{"id":171294,"date":"2026-08-04T11:52:24","date_gmt":"2026-08-04T11:52:24","guid":{"rendered":"https:\/\/pabau.com\/?p=171294"},"modified":"2026-08-17T11:45:32","modified_gmt":"2026-08-17T11:45:32","slug":"cpt-code-01420","status":"publish","type":"post","link":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/","title":{"rendered":"CPT code 01420: Anesthesia for knee cast procedures"},"content":{"rendered":"\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"MedicalWebPage\",\"headline\":\"CPT code 01420: Anesthesia for knee cast procedures\",\"description\":\"CPT code 01420 covers anesthesia for all cast applications, removal, or repair involving the knee joint, at 3 base units. Billing rules, modifiers, Medicare payment, and ICD-10 pairings.\",\"url\":\"https:\/\/pabau.com\/procedure-codes\/cpt-code-01420\/\",\"audience\":{\"@type\":\"MedicalAudience\",\"audienceType\":\"Clinician\"},\"reviewedBy\":{\"@type\":\"Person\",\"name\":\"Dr Vanja Kitanova\",\"jobTitle\":\"Medical Reviewer\",\"affiliation\":{\"@type\":\"Organization\",\"name\":\"Pabau\"},\"knowsAbout\":[\"Medical Coding\",\"Clinical Documentation\",\"Healthcare Billing\",\"Clinical Safety\"],\"sameAs\":\"https:\/\/pabau.com\/blog\/author\/vanja\/\"},\"datePublished\":\"2026-08-04\",\"dateModified\":\"2026-08-04\"}<\/script>\n\n\n        <div id=\"key_takeaways\">\n            <div class=\"header\">\n                                    <img decoding=\"async\" src=\"https:\/\/pabau.com\/wp-content\/uploads\/2025\/12\/Key-Takeaways-Icon.svg\" alt=\"Key takeaways\" height=\"42\" width=\"42\">\n                                <h3>Key takeaways<\/h3>\n            <\/div>\n            <div class=\"list\">\n                                                            <div class=\"item\">\n                            <div>\n                                <svg width=\"20\" height=\"27\" viewBox=\"0 0 20 27\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                                    <path\n                                        d=\"M18.6223 14.3857C19.1246 13.8975 19.1246 13.1045 18.6223 12.6162L12.1938 6.36621C11.6915 5.87793 10.8759 5.87793 10.3737 6.36621C9.87143 6.85449 9.87143 7.64746 10.3737 8.13574L14.6125 12.2529H2.28571C1.57455 12.2529 1 12.8115 1 13.5029C1 14.1943 1.57455 14.7529 2.28571 14.7529H14.6085L10.3777 18.8701C9.87545 19.3584 9.87545 20.1514 10.3777 20.6396C10.8799 21.1279 11.6955 21.1279 12.1978 20.6396L18.6263 14.3896L18.6223 14.3857Z\"\n                                        fill=\"#3D3D46\" \/>\n                                <\/svg>\n                            <\/div>\n                            <p>CPT code 01420 covers anesthesia for all cast applications, removal, or repair involving the knee joint.<\/p>\n                        <\/div>\n                                                                                <div class=\"item\">\n                            <div>\n                                <svg width=\"20\" height=\"27\" viewBox=\"0 0 20 27\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                                    <path\n                                        d=\"M18.6223 14.3857C19.1246 13.8975 19.1246 13.1045 18.6223 12.6162L12.1938 6.36621C11.6915 5.87793 10.8759 5.87793 10.3737 6.36621C9.87143 6.85449 9.87143 7.64746 10.3737 8.13574L14.6125 12.2529H2.28571C1.57455 12.2529 1 12.8115 1 13.5029C1 14.1943 1.57455 14.7529 2.28571 14.7529H14.6085L10.3777 18.8701C9.87545 19.3584 9.87545 20.1514 10.3777 20.6396C10.8799 21.1279 11.6955 21.1279 12.1978 20.6396L18.6263 14.3896L18.6223 14.3857Z\"\n                                        fill=\"#3D3D46\" \/>\n                                <\/svg>\n                            <\/div>\n                            <p>The code covers casting work rather than knee surgery, and it carries 3 base units in the ASA Relative Value Guide.<\/p>\n                        <\/div>\n                                                                                <div class=\"item\">\n                            <div>\n                                <svg width=\"20\" height=\"27\" viewBox=\"0 0 20 27\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                                    <path\n                                        d=\"M18.6223 14.3857C19.1246 13.8975 19.1246 13.1045 18.6223 12.6162L12.1938 6.36621C11.6915 5.87793 10.8759 5.87793 10.3737 6.36621C9.87143 6.85449 9.87143 7.64746 10.3737 8.13574L14.6125 12.2529H2.28571C1.57455 12.2529 1 12.8115 1 13.5029C1 14.1943 1.57455 14.7529 2.28571 14.7529H14.6085L10.3777 18.8701C9.87545 19.3584 9.87545 20.1514 10.3777 20.6396C10.8799 21.1279 11.6955 21.1279 12.1978 20.6396L18.6263 14.3896L18.6223 14.3857Z\"\n                                        fill=\"#3D3D46\" \/>\n                                <\/svg>\n                            <\/div>\n                            <p>Knee surgery anesthesia belongs elsewhere: 01380 for closed procedures, 01400 for open or arthroscopic, 01402 for total knee arthroplasty.<\/p>\n                        <\/div>\n                                                                                <div class=\"item\">\n                            <div>\n                                <svg width=\"20\" height=\"27\" viewBox=\"0 0 20 27\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                                    <path\n                                        d=\"M18.6223 14.3857C19.1246 13.8975 19.1246 13.1045 18.6223 12.6162L12.1938 6.36621C11.6915 5.87793 10.8759 5.87793 10.3737 6.36621C9.87143 6.85449 9.87143 7.64746 10.3737 8.13574L14.6125 12.2529H2.28571C1.57455 12.2529 1 12.8115 1 13.5029C1 14.1943 1.57455 14.7529 2.28571 14.7529H14.6085L10.3777 18.8701C9.87545 19.3584 9.87545 20.1514 10.3777 20.6396C10.8799 21.1279 11.6955 21.1279 12.1978 20.6396L18.6263 14.3896L18.6223 14.3857Z\"\n                                        fill=\"#3D3D46\" \/>\n                                <\/svg>\n                            <\/div>\n                            <p>Total units are base units plus time units plus qualifying circumstance units, and every claim needs a physical status and a provider-role modifier.<\/p>\n                        <\/div>\n                                                                                <div class=\"item\">\n                            <div>\n                                <svg width=\"20\" height=\"27\" viewBox=\"0 0 20 27\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                                    <path\n                                        d=\"M18.6223 14.3857C19.1246 13.8975 19.1246 13.1045 18.6223 12.6162L12.1938 6.36621C11.6915 5.87793 10.8759 5.87793 10.3737 6.36621C9.87143 6.85449 9.87143 7.64746 10.3737 8.13574L14.6125 12.2529H2.28571C1.57455 12.2529 1 12.8115 1 13.5029C1 14.1943 1.57455 14.7529 2.28571 14.7529H14.6085L10.3777 18.8701C9.87545 19.3584 9.87545 20.1514 10.3777 20.6396C10.8799 21.1279 11.6955 21.1279 12.1978 20.6396L18.6263 14.3896L18.6223 14.3857Z\"\n                                        fill=\"#3D3D46\" \/>\n                                <\/svg>\n                            <\/div>\n                            <p>Practice management software like Pabau keeps anesthesia times, modifiers, and diagnosis codes in one patient record, so claims go out complete.<\/p>\n                        <\/div>\n                                                <\/div>\n        <\/div>\n    \n\n\n<p class=\"wp-block-paragraph\">CPT code 01420 covers anesthesia for cast work on the knee, not knee surgery. The official descriptor is <strong>Anesthesia for all cast applications, removal, or repair involving knee joint<\/strong>. The procedure being anesthetized is the cast. That&#8217;s easy to miss, because the code sits in the middle of the knee surgery series and reads like a catch-all.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That distinction changes the base unit value, the diagnosis codes that support the claim, and the payment. 01420 carries 3 base units. A total knee replacement carries 7 under 01402. Accurate <a href=\"https:\/\/pabau.com\/features\/claims-management-software\/\">claims management<\/a> on this code starts with reading the descriptor rather than the code number.<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\">\n<div class=\"wp-block-embed__wrapper\">\n<iframe title=\"CPT Coding Pitfalls Every Medical Practice Faces\" width=\"800\" height=\"450\" src=\"https:\/\/www.youtube.com\/embed\/vbvV5okdXKg?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div>\n<\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">CPT code 01420: Descriptor and clinical scope<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">CPT code 01420 carries the official descriptor <strong>Anesthesia for all cast applications, removal, or repair involving knee joint<\/strong>. It sits in the Anesthesia for Procedures on the Knee and Popliteal Area subsection, codes 01320 to 01444. The <a href=\"https:\/\/www.ama-assn.org\/practice-management\/cpt\/cpt-code-set-overview\" target=\"_blank\" rel=\"nofollow noopener\">American Medical Association (AMA)<\/a> maintains the CPT code set.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The word \u00aball\u00bb in the descriptor refers to all cast work, not all knee procedures. Three activities fall inside it: applying a cast that crosses the knee, removing or bivalving one, and repairing one already in place. The joint itself is not opened, reduced, or instrumented.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Anesthesia for a cast is the exception rather than the rule, so payers look closely at these claims. The usual reasons are a young child who cannot hold position, a patient with spasticity, or a fixed contracture.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Those last two often sit on a rehabilitation or occupational therapy caseload, where serial casting is a planned part of treatment. Severe pain on manipulation and an otherwise intolerable cast change also qualify. The anesthesia record should say which of those applied.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">One boundary matters more than any other. If the surgeon reduces or manipulates the knee joint during the same session, the closed-procedure code 01380 applies instead. And if a cast goes on at the end of knee surgery, the surgical anesthesia code already covers the whole anesthesia period. Adding 01420 on top of it is duplicate billing.<\/p>\n\n\n        <div id=\"pro_tip\">\n            <div class=\"img\">\n                <svg width=\"42\" height=\"42\" viewBox=\"0 0 42 42\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                    <path fill-rule=\"evenodd\" clip-rule=\"evenodd\"\n                        d=\"M12.6383 19.5238C12.6632 21.2071 12.8734 22.9926 12.0685 24.5523C11.0341 26.8917 8.45076 28.169 7.56292 30.5918C6.63082 33.1061 7.19505 36.185 9.31371 37.9786C10.929 39.5678 13.4183 39.9873 15.6061 39.5463C17.4592 39.073 19.1049 37.8388 19.9706 36.1608C20.781 34.7141 20.7866 32.9904 20.5293 31.3985C20.1006 29.3092 18.3775 27.8705 16.9807 26.362C14.8814 24.1005 14.6684 20.6854 15.595 17.8915C16.4331 15.4768 19.0026 14.2344 20.0425 11.9461C20.7202 10.6769 20.7506 9.20327 20.6068 7.81304C20.1864 5.40098 18.3139 3.23631 15.8716 2.56674C13.9742 2.03969 11.8224 2.30052 10.1739 3.37614C8.70522 4.34688 7.5878 5.86618 7.28356 7.58178C6.76081 9.82981 7.53525 12.2822 9.20307 13.9118C10.7658 15.4741 12.4806 17.2273 12.6383 19.5238Z\"\n                        fill=\"#2BADD4\" \/>\n                    <path fill-rule=\"evenodd\" clip-rule=\"evenodd\"\n                        d=\"M22.7048 19.8387C22.6822 22.3279 24.4507 24.6234 26.7493 25.4682C28.0531 25.961 29.4725 25.9183 30.7989 25.5487C32.0575 24.9955 33.301 24.2237 34.0069 23.0092C34.8384 21.5811 35.2982 19.8286 34.7832 18.2094C34.3611 16.2507 32.8739 14.6541 31.0275 13.9426C28.6736 12.9595 25.8073 13.7942 24.1719 15.7001C23.2022 16.8366 22.6143 18.3326 22.7048 19.8387Z\"\n                        fill=\"#2BADD4\" \/>\n                <\/svg>\n            <\/div>\n            <div class=\"text\">\n                <h3>Pro Tip<\/h3>\n                <p>Read the operative note before you pick the code. The schedule entry is not enough. A case booked as \u00abknee cast under anesthesia\u00bb often turns out to include a closed reduction. That moves the claim to 01380, which is a different descriptor at the same 3 base units.<\/p>\n            <\/div>\n        <\/div>\n    \n\n\n<h2 class=\"wp-block-heading\">Procedures covered under CPT code 01420<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">01420 is an anesthesia code, so it never travels alone. It reports the anesthesia service for a surgical CPT code in the casting series. The table below maps 01420 to the cast procedures it accompanies most often, all of which cross or involve the knee joint.<\/p>\n\n\n\n<table style=\"width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;font-size:15px;line-height:1.5;margin:1.5em 0 2em;box-shadow:0 2px 12px rgba(0,0,0,0.08)\">\n<thead>\n<tr>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Surgical CPT code<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Procedure<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Why 01420 fits<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">29345<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Application of long leg cast (thigh to toes)<\/td>\n<td style=\"padding:12px 16px;color:#374151\">The cast spans the knee joint<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">29355<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Application of long leg cast, walker or ambulatory type<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Same span, weight-bearing version<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">29358<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Application of long leg cast brace<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Brace-type cast crossing the knee<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">29365<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Application of cylinder cast (thigh to ankle)<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Standard cast for a stable patellar fracture<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">29505<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Application of long leg splint (thigh to ankle or toes)<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Splint immobilizing the knee<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">29705<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Removal or bivalving; full arm or full leg cast<\/td>\n<td style=\"padding:12px 16px;color:#374151\">The removal half of the descriptor<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">29730<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Windowing of cast<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Cast repair work on a cast already in place<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">29740<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Wedging of cast (except clubfoot casts)<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Cast repair to correct alignment<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">Casts that stop below the knee do not qualify. A short leg cast is a lower leg procedure, so the anesthesia code comes from the 01462-01522 range instead. Check where the cast starts and stops before you code the anesthesia.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Code details at a glance<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The table below is the quick reference billers need before building a 01420 claim.<\/p>\n\n\n\n<table style=\"width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;font-size:15px;line-height:1.5;margin:1.5em 0 2em;box-shadow:0 2px 12px rgba(0,0,0,0.08)\">\n<thead>\n<tr>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Field<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Detail<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Code number<\/td>\n<td style=\"padding:12px 16px;color:#374151\">01420<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Short descriptor<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia, knee cast application, removal or repair<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Long descriptor<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia for all cast applications, removal, or repair involving knee joint<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">CPT subsection<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia for Procedures on the Knee and Popliteal Area (01320-01444)<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">ASA base units<\/td>\n<td style=\"padding:12px 16px;color:#374151\">3<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Code type<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Standalone anesthesia code<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Not for<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Knee arthroplasty, arthroscopy, ligament repair, or closed reduction<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Maintained by<\/td>\n<td style=\"padding:12px 16px;color:#374151\">American Medical Association (AMA)<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Base units source<\/td>\n<td style=\"padding:12px 16px;color:#374151\">ASA Relative Value Guide (RVG)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<h2 class=\"wp-block-heading\">Base units and total anesthesia unit calculation<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">CPT code 01420 carries <strong>3 base units<\/strong>, assigned by the American Society of Anesthesiologists (ASA) in its Relative Value Guide (RVG). The Centers for Medicare and Medicaid Services (CMS) adopts that value.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Base units reflect the inherent complexity and risk of the anesthesia service. Three units is the floor of the knee series, which fits a procedure that does not enter the joint.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If you have been billing 01420 at 4 base units, the source of the error is usually a crosswalk that confuses it with 01400. That code sits at 4 units and covers open or arthroscopic knee surgery. Total anesthesia units on any 01420 claim follow this formula.<\/p>\n\n\n\n<table style=\"width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;font-size:15px;line-height:1.5;margin:1.5em 0 2em;box-shadow:0 2px 12px rgba(0,0,0,0.08)\">\n<thead>\n<tr>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Component<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Description<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:center;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Example (45-min case)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Base units<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Fixed value assigned by ASA for CPT code 01420<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">3<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Time units<\/td>\n<td style=\"padding:12px 16px;color:#374151\">1 unit per 15 minutes of anesthesia time (payer-dependent)<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">3 (45 min \/ 15)<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Qualifying circumstance units<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Add-on units from codes 99100-99140, if applicable<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">0 or variable<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\"><strong>Total units<\/strong><\/td>\n<td style=\"padding:12px 16px;color:#374151\">Base + time + qualifying circumstance<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\"><strong>6<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">So a 45-minute cast application gives 3 base units plus 3 time units, for 6 total units. Multiply that by the payer&#8217;s anesthesia conversion factor to get the dollar payment. Cast cases are usually short, which means base units make up a larger share of the total than they do on a two-hour surgical case.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Anesthesia time units<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Most Medicare and commercial payers use 1 time unit per 15 minutes of anesthesia time. Some commercial payers use a 10-minute increment. Medicare contractors divide the reported minutes by 15 and keep the fraction, so 40 minutes becomes 2.7 time units rather than 2. Verify the increment and the rounding rule with each payer.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Time runs from the point the anesthesia provider begins preparing the patient until they are no longer in personal attendance. On a cast case that window can be barely longer than the procedure itself, so short-case documentation has to be precise. Reporting the cast application time instead of the anesthesia time is the most common audit flag on these claims.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Qualifying circumstance add-on codes<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Qualifying circumstance codes add units when a documented condition made the anesthesia harder. They are add-on codes billed alongside 01420, not modifiers. Two of the four rarely have anything to do with a cast, and billing them on a casting claim invites a review.<\/p>\n\n\n\n<table style=\"width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;font-size:15px;line-height:1.5;margin:1.5em 0 2em;box-shadow:0 2px 12px rgba(0,0,0,0.08)\">\n<thead>\n<tr>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Code<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Descriptor<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:center;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">ASA units<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Applicability with 01420<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">99100<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia for patient of extreme age, younger than 1 year and older than seventy<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">1<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Often applies, since many knee cast cases are pediatric<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">99116<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia complicated by utilization of total body hypothermia<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">5<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Not clinically plausible for a cast procedure<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">99135<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia complicated by utilization of controlled hypotension<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">5<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Not clinically plausible for a cast procedure<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">99140<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia complicated by emergency conditions (specify)<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">2<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Applies when the cast goes on under emergent conditions<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">Traditional Medicare does not pay these codes separately. CMS gives 99100 through 99140 a status indicator of B, which bundles their value into the primary anesthesia code. Many commercial payers do recognize them, so the units are worth reporting where the contract allows it.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Physical status modifiers<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Every anesthesia claim, including an 01420 claim, needs a physical status modifier describing the patient&#8217;s health at the time of the procedure. These modifiers come from the ASA Physical Status Classification System. Payers differ on whether they add units for them, and some commercial plans pay nothing extra for P3 and above.<\/p>\n\n\n\n<table style=\"width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;font-size:15px;line-height:1.5;margin:1.5em 0 2em;box-shadow:0 2px 12px rgba(0,0,0,0.08)\">\n<thead>\n<tr>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Modifier<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Description<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:center;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Additional units (ASA RVG)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">P1<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Normal healthy patient<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">0<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">P2<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Patient with mild systemic disease<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">0<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">P3<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Patient with severe systemic disease<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">1<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">P4<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Patient with severe systemic disease that is a constant threat to life<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">2<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">P5<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Moribund patient not expected to survive without the operation<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">3<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">P6<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Brain-dead patient whose organs are being removed for donor purposes<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">Most knee cast cases are P1 or P2. P3 shows up more often on this code than you might expect. Patients who need anesthesia for a cast often have a neurological or developmental condition behind that need. Each modifier has to be supported by the pre-anesthesia assessment. Using structured medical forms for that assessment keeps the supporting detail on file.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Anesthesia modifiers: AA, QK, QX, QY, and QZ<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Provider-role modifiers say who delivered the anesthesia and whether medical direction applied. They set the percentage of the allowed amount that Medicare and most commercial payers pay. Every 01420 claim carries one of them.<\/p>\n\n\n\n<table style=\"width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;font-size:15px;line-height:1.5;margin:1.5em 0 2em;box-shadow:0 2px 12px rgba(0,0,0,0.08)\">\n<thead>\n<tr>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Modifier<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Description<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Payment rate (Medicare)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">AA<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia services personally performed by an anesthesiologist<\/td>\n<td style=\"padding:12px 16px;color:#374151\">100% of allowed amount<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">QK<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Medical direction of 2-4 concurrent anesthesia procedures by a physician<\/td>\n<td style=\"padding:12px 16px;color:#374151\">50% of allowed amount<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">QX<\/td>\n<td style=\"padding:12px 16px;color:#374151\">CRNA service with medical direction by a physician<\/td>\n<td style=\"padding:12px 16px;color:#374151\">50% of allowed amount<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">QY<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Medical direction of one CRNA by an anesthesiologist<\/td>\n<td style=\"padding:12px 16px;color:#374151\">50% of allowed amount<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">QZ<\/td>\n<td style=\"padding:12px 16px;color:#374151\">CRNA service without medical direction by a physician<\/td>\n<td style=\"padding:12px 16px;color:#374151\">100% of allowed amount<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<h3 class=\"wp-block-heading\">Medical direction rules and their impact on billing<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">CMS medical direction requires the anesthesiologist to perform and document seven steps for each directed case. Short cases make this harder rather than easier. The whole anesthetic may last 20 minutes, and all seven steps still have to land inside it.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Perform a pre-anesthetic examination and evaluation<\/li><li>Prescribe the anesthesia plan<\/li><li>Personally participate in the most demanding parts of the plan, including induction and emergence where applicable<\/li><li>Ensure that any part of the plan they do not perform is performed by a qualified anesthetist<\/li><li>Monitor the course of anesthesia administration at frequent intervals<\/li><li>Remain physically present and available for immediate diagnosis and treatment of emergencies<\/li><li>Provide the indicated post-anesthesia care<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">When all seven are met for 2-4 concurrent cases, the anesthesiologist reports QK and the CRNA reports QX. QY is for a single directed CRNA. Missing even one documented step can downcode the claim or trigger a post-payment review.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Medicare reimbursement for CPT code 01420<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Medicare pays anesthesia using an anesthesia conversion factor (CF) set each year by CMS. The formula is <strong>payment = total anesthesia units x anesthesia conversion factor<\/strong>. The national figures are $20.4349 per unit for 2024 and $20.3178 for 2025.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For 2026, CMS finalized two national anesthesia conversion factors: $20.4976 for most clinicians and $20.5998 for those in a qualifying Advanced Alternative Payment Model. Current locality figures live in the <a href=\"https:\/\/www.cms.gov\/medicare\/physician-fee-schedule\/search\/overview\" target=\"_blank\" rel=\"nofollow noopener\">CMS Physician Fee Schedule lookup tool<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Geographic locality matters. Medicare pays a different conversion factor depending on where the service is rendered. The same 01420 claim pays more in San Francisco than in rural Mississippi. Always check the locality rate before you quote a number to anyone.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The examples below use the 2024 national figure of $20.4349 and the correct 3 base units. They show why a coding error on this line is small per claim and large across a year.<\/p>\n\n\n\n<table style=\"width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;font-size:15px;line-height:1.5;margin:1.5em 0 2em;box-shadow:0 2px 12px rgba(0,0,0,0.08)\">\n<thead>\n<tr>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Scenario<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:center;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Total units<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:center;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">CF (2024 national)<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:center;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Estimated payment<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">30-min cast application, P1, AA modifier<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">5 (3 base + 2 time)<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">$20.4349<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">$102.17<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">45-min cast application, P2, AA modifier<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">6 (3 base + 3 time)<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">$20.4349<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">$122.61<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">60-min cast change, P2, QK and QX split<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">7, paid at 50% each<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">$20.4349<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">$71.52 per provider<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">Compare that with billing the same case at 4 base units. A 45-minute case would come out at 7 units and $143.04, which is $20.43 more than Medicare allows. Across a pediatric orthopedic service running several of these a week, the overpayment is the kind of pattern a post-payment audit finds easily.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">ICD-10 diagnosis codes that support an 01420 claim<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Anesthesia claims need an ICD-10-CM diagnosis that establishes medical necessity. For 01420 the diagnosis has to explain the cast rather than a knee operation. Osteoarthritis and ligament tears belong on surgical anesthesia claims, and a payer can spot that mismatch from the claim alone.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The codes below reflect conditions that genuinely lead to a cast crossing the knee. They support patient care management documentation as well as the claim.<\/p>\n\n\n\n<table style=\"width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;font-size:15px;line-height:1.5;margin:1.5em 0 2em;box-shadow:0 2px 12px rgba(0,0,0,0.08)\">\n<thead>\n<tr>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">ICD-10-CM code<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Description<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Casting context<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">S82.001A<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Unspecified fracture of right patella, initial encounter for closed fracture<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Cylinder cast for a stable patellar fracture<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">S82.002A<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Unspecified fracture of left patella, initial encounter for closed fracture<\/td>\n<td style=\"padding:12px 16px;color:#374151\">The same presentation on the left side<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">S82.101A<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Unspecified fracture of upper end of right tibia, initial encounter for closed fracture<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Long leg cast for a proximal tibia fracture<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">S72.401A<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Unspecified fracture of lower end of right femur, initial encounter for closed fracture<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Long leg or cylinder cast spanning the knee<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">S82.001D<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Unspecified fracture of right patella, subsequent encounter for closed fracture with routine healing<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Cast removal or cast change at a follow-up visit<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M24.561<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Contracture, right knee<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Serial casting for a fixed knee flexion contracture<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Z47.89<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Encounter for other orthopedic aftercare<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Planned cast repair or replacement with no new injury<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">Two details on this table decide whether the claim pays. Fracture codes need the right seventh character, so A for the initial encounter and D for a subsequent encounter with routine healing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Laterality is the other one, and it turns on a single digit. S82.001A is the right patella, S82.002A the left. An unspecified-side code on a limb injury is one of the fastest ways to earn a denial.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Serial casting for a contracture usually runs alongside a physical therapy program, so M24.561 fits the claim better than any arthritis code. Pediatric orthopedic services should get the diagnosis to the anesthesia team before the claim is built. Mismatched diagnosis codes remain a leading cause of medical necessity denials on anesthesia lines.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Related anesthesia CPT codes for the knee<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">This is the table most people looking up 01420 need. The knee series splits by what is done to the joint, and the base units move with it. If the operation was knee surgery rather than cast work, your code is somewhere else in this list. Base units below come from the ASA Relative Value Guide.<\/p>\n\n\n\n<table style=\"width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;font-size:15px;line-height:1.5;margin:1.5em 0 2em;box-shadow:0 2px 12px rgba(0,0,0,0.08)\">\n<thead>\n<tr>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">CPT code<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Descriptor<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:center;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Base units<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">When it applies instead of 01420<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">01380<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia for all closed procedures on knee joint<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">3<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Closed reduction or manipulation of the knee joint<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">01382<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia for diagnostic arthroscopic procedures of knee joint<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">3<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Diagnostic knee arthroscopy with no surgical repair<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">01400<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia for open or surgical arthroscopic procedures on knee joint; not otherwise specified<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">4<\/td>\n<td style=\"padding:12px 16px;color:#374151\">ACL reconstruction, meniscectomy, synovectomy, patellar surgery<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">01402<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia for open or surgical arthroscopic procedures on knee joint; total knee arthroplasty<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">7<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Total knee replacement<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">01404<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia for open or surgical arthroscopic procedures on knee joint; disarticulation at knee<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">5<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Amputation or disarticulation at the knee<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\"><strong>01420<\/strong><\/td>\n<td style=\"padding:12px 16px;color:#374151\"><strong>Anesthesia for all cast applications, removal, or repair involving knee joint<\/strong><\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\"><strong>3<\/strong><\/td>\n<td style=\"padding:12px 16px;color:#374151\"><strong>The cast is the procedure<\/strong><\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\"><a href=\"https:\/\/pabau.com\/procedure-codes\/cpt-code-01430\/\">01430<\/a><\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia for procedures on veins of knee and popliteal area; not otherwise specified<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">3<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Venous procedures in the popliteal fossa<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\"><a href=\"https:\/\/pabau.com\/procedure-codes\/cpt-code-01440\/\">01440<\/a><\/td>\n<td style=\"padding:12px 16px;color:#374151\">Anesthesia for procedures on arteries of knee and popliteal area; not otherwise specified<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">8<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Arterial procedures in the popliteal fossa<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">Read the spread of base units in that column, because it is the whole argument for getting this right. The same anatomical region runs from 3 units to 8. Coding a total knee arthroplasty as 01420 gives away 4 base units, and coding a cast change as 01440 overbills by 5.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The series also has an edge at the femur. An open procedure on the lower third of the femur leaves the knee codes behind and reports under 01360.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Billing guidelines and common claim errors<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">01420 denials cluster around a handful of recurring mistakes, and most of them start in the record rather than in the billing system. Structured HIPAA-compliant documentation in the anesthesia department removes a lot of that risk.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Documentation requirements<\/h3>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>Anesthesia start and stop times<\/strong> recorded to the minute, with a note on what those times represent<\/li><li><strong>The reason anesthesia was needed for a cast<\/strong>, such as age, spasticity, contracture, or intolerable pain<\/li><li><strong>Physical status modifier<\/strong> supported by a pre-anesthesia evaluation note<\/li><li><strong>Provider-role modifier<\/strong> (AA, QK, QX, QY, or QZ) matched to entries in the anesthesia record<\/li><li><strong>ICD-10-CM diagnosis code<\/strong> that explains the cast, with the correct laterality and seventh character<\/li><li><strong>Qualifying circumstance rationale<\/strong> if 99100 or 99140 is added to the claim<\/li><\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Common denial reasons for 01420 claims<\/h3>\n\n\n\n<table style=\"width:100%;border-collapse:separate;border-spacing:0;border-radius:12px;overflow:hidden;font-size:15px;line-height:1.5;margin:1.5em 0 2em;box-shadow:0 2px 12px rgba(0,0,0,0.08)\">\n<thead>\n<tr>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Error type<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">What goes wrong<\/th>\n<th style=\"background:#121D36;color:#fff;padding:14px 16px;text-align:left;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">How to prevent it<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Wrong code from the same family<\/td>\n<td style=\"padding:12px 16px;color:#374151\">01420 billed for knee surgery, or a surgical code billed for cast work<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Match the descriptor to the operative note, not the code number<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Wrong base units<\/td>\n<td style=\"padding:12px 16px;color:#374151\">01420 billed at 4 units after a crosswalk mix-up with 01400<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Lock 3 base units into the fee schedule and audit the line<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Cast bundled into surgery<\/td>\n<td style=\"padding:12px 16px;color:#374151\">01420 added when a cast went on at the end of knee surgery<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Bill only the surgical anesthesia code for that session<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Missing medical necessity<\/td>\n<td style=\"padding:12px 16px;color:#374151\">No record of why the cast needed anesthesia at all<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Document the clinical reason in the pre-anesthesia note<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Diagnosis mismatch<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Osteoarthritis or a ligament tear paired with a casting code<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Use a fracture, contracture, or aftercare diagnosis<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Laterality error<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Unspecified-side code used on a limb fracture<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Confirm side and seventh character before submission<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Missing modifier<\/td>\n<td style=\"padding:12px 16px;color:#374151\">No AA, QK, QX, QY, or QZ on the claim<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Include a provider-role modifier on every anesthesia line<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">Using digital forms for pre-anesthesia intake captures the physical status and history fields that support modifier choice. Practices that connect intake data to billing keep the claim aligned with what the clinician recorded. The Pabau blog covers the wider workflow in its guide to EHR integration.<\/p>\n\n\n        <div id=\"pro_tip\">\n            <div class=\"img\">\n                <svg width=\"42\" height=\"42\" viewBox=\"0 0 42 42\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                    <path fill-rule=\"evenodd\" clip-rule=\"evenodd\"\n                        d=\"M12.6383 19.5238C12.6632 21.2071 12.8734 22.9926 12.0685 24.5523C11.0341 26.8917 8.45076 28.169 7.56292 30.5918C6.63082 33.1061 7.19505 36.185 9.31371 37.9786C10.929 39.5678 13.4183 39.9873 15.6061 39.5463C17.4592 39.073 19.1049 37.8388 19.9706 36.1608C20.781 34.7141 20.7866 32.9904 20.5293 31.3985C20.1006 29.3092 18.3775 27.8705 16.9807 26.362C14.8814 24.1005 14.6684 20.6854 15.595 17.8915C16.4331 15.4768 19.0026 14.2344 20.0425 11.9461C20.7202 10.6769 20.7506 9.20327 20.6068 7.81304C20.1864 5.40098 18.3139 3.23631 15.8716 2.56674C13.9742 2.03969 11.8224 2.30052 10.1739 3.37614C8.70522 4.34688 7.5878 5.86618 7.28356 7.58178C6.76081 9.82981 7.53525 12.2822 9.20307 13.9118C10.7658 15.4741 12.4806 17.2273 12.6383 19.5238Z\"\n                        fill=\"#2BADD4\" \/>\n                    <path fill-rule=\"evenodd\" clip-rule=\"evenodd\"\n                        d=\"M22.7048 19.8387C22.6822 22.3279 24.4507 24.6234 26.7493 25.4682C28.0531 25.961 29.4725 25.9183 30.7989 25.5487C32.0575 24.9955 33.301 24.2237 34.0069 23.0092C34.8384 21.5811 35.2982 19.8286 34.7832 18.2094C34.3611 16.2507 32.8739 14.6541 31.0275 13.9426C28.6736 12.9595 25.8073 13.7942 24.1719 15.7001C23.2022 16.8366 22.6143 18.3326 22.7048 19.8387Z\"\n                        fill=\"#2BADD4\" \/>\n                <\/svg>\n            <\/div>\n            <div class=\"text\">\n                <h3>Pro Tip<\/h3>\n                <p>Run a quarterly audit of every 01420 line you submitted. Sort by the surgical CPT code on the same claim. Anything paired with 29881, 29888, or 27447 is a miscode, because those are arthroscopy and arthroplasty procedures that belong to 01400 and 01402.<\/p>\n            <\/div>\n        <\/div>\n    \n\n\n<p class=\"wp-block-paragraph\">For code-level verification, the <a href=\"https:\/\/www.aapc.com\/codes\/cpt-codes-range\/\" target=\"_blank\" rel=\"nofollow noopener\">AAPC Codify CPT lookup<\/a> gives descriptor and modifier detail for every code in the knee series.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Related CPT codes<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/pabau.com\/procedure-codes\/cpt-code-00940\/\">CPT code 00940 \u2014 Anesthesia for vaginal procedures<\/a><\/li>\n\n\n<li><a href=\"https:\/\/pabau.com\/procedure-codes\/cpt-code-01432\/\">CPT code 01432 \u2014 Billing for knee and popliteal AV fistula<\/a><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">How Pabau supports anesthesia claim accuracy<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The 01420 problem is a documentation problem before it is a billing problem. The reason anesthesia was needed for a cast sits in the pre-anesthesia note. The start and stop times sit in the anesthesia record, and the diagnosis sits with the surgeon.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When those three live in separate places, the biller reconstructs the claim from memory and picks the code that sounds right.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Practice management software like Pabau keeps them in one patient record. Intake and consent forms are customizable. A pre-anesthesia form can carry the physical status classification, the reason for anesthesia, and the side being treated as required fields. Nothing moves forward with those blank, so the biller is not guessing later.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Treatment notes, times, forms, and the diagnosis then sit against the same appointment. Your billing team can see whether a cast was the procedure or the closing step of knee surgery before the claim goes out. That&#8217;s the difference between a clean 01420 line and a denial you appeal three weeks later.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"https:\/\/cdn.pabau.com\/cdn\/attachments\/pulse\/content-engine\/billing_codes\/cpt-code-01420\/customizable-consent-and-intake-forms.webp\" alt=\"Customizable consent and intake forms in Pabau\"\/><figcaption class=\"wp-element-caption\"><em>Pabau&#8217;s customizable intake and consent forms capture physical status and the reason for anesthesia, so every 01420 claim ships with its support.<\/em><\/figcaption><\/figure>\n\n\n\n<div style=\"height:35px;width:800px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n        <div id=\"book_a_demo\">\n            <div class=\"left-side\">\n                <div class=\"logo\">\n                    <img decoding=\"async\"\n                        src=\"https:\/\/pabau.com\/wp-content\/uploads\/2026\/01\/Logo.svg\"\n                        alt=\"Logo\"\n                        loading=\"lazy\"\n                    \/>\n                <\/div>\n\n                <h3 class=\"heading\">\n                    Keep anesthesia claims tied to the record                <\/h3>\n\n                <p class=\"description\">\n                    Pabau keeps pre-anesthesia forms, procedure times, and diagnosis codes on one patient record. Your team can then code from the record rather than the schedule entry.                <\/p>\n\n                <div class=\"button-group\">\n                    <a href=\"\/book-demo\/\" class=\"btn btn-scale-effect btn-cta-color btn-md\">\n                        <span class=\"btn-text\">Book a demo<\/span>\n                        <div class=\"btn-icon btn-icon-right\" aria-hidden=\"true\">\n                            <svg\n                                width=\"14\"\n                                height=\"12\"\n                                viewBox=\"0 0 14 12\"\n                                fill=\"none\"\n                                xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\n                            >\n                                <path\n                                    d=\"M0.75 4.77295C0.335786 4.77295 0 5.10874 0 5.52295C0 5.93716 0.335786 6.27295 0.75 6.27295V5.52295V4.77295ZM13.2803 6.05328C13.5732 5.76039 13.5732 5.28551 13.2803 4.99262L8.50736 0.219648C8.21447 -0.073245 7.73959 -0.073245 7.4467 0.219648C7.15381 0.512542 7.15381 0.987415 7.4467 1.28031L11.6893 5.52295L7.4467 9.76559C7.15381 10.0585 7.15381 10.5334 7.4467 10.8263C7.73959 11.1191 8.21447 11.1191 8.50736 10.8263L13.2803 6.05328ZM0.75 5.52295V6.27295L12.75 6.27295V5.52295V4.77295L0.75 4.77295V5.52295Z\"\n                                    fill=\"currentColor\"\n                                ><\/path>\n                            <\/svg>\n                        <\/div>\n                    <\/a>\n                <\/div>\n            <\/div>\n\n            <div class=\"right-side\">\n                <img decoding=\"async\"\n                    src=\"https:\/\/pabau.com\/wp-content\/uploads\/2026\/01\/Home-Page-Concept-4.webp\"\n                    alt=\"Pabau claims management dashboard\"\n                    loading=\"lazy\"\n                \/>\n            <\/div>\n        <\/div>\n        \n\n\n<h2 class=\"wp-block-heading\">Conclusion<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If you take one thing from this guide, make it the descriptor. CPT code 01420 is a cast code at 3 base units. Every claim you built on the idea that it covers knee surgery is wrong in two directions. The units are off, and so is the diagnosis supporting them.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The fix is cheap and worth doing this week. Pull your last quarter of 01420 lines and check the surgical code beside each one. Then confirm your fee schedule holds 3 base units rather than 4.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Where the case was an arthroplasty or an arthroscopy, the code you wanted was 01402 or 01400. Fixing it now costs a corrected claim. Leaving it costs an audit.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The trade-off worth remembering is that short cases magnify base unit errors. On a 30-minute cast, base units are more than half the payment, so a one-unit mistake moves the whole line. <a href=\"https:\/\/pabau.com\/book-demo\/\">Book a demo<\/a> to see how Pabau keeps anesthesia documentation and diagnosis codes together so your claims match the record.<\/p>\n\n\n        <div id=\"expert_picks\">\n            <div class=\"header\">\n                                    <img decoding=\"async\" src=\"https:\/\/pabau.com\/wp-content\/uploads\/2025\/11\/Expert-Picks.svg\" alt=\"Continue your research\" height=\"42\" width=\"42\">\n                                <h3>Continue your research<\/h3>\n            <\/div>\n            <div class=\"content\">\n                                                            <div class=\"item\">\n                            <div>\n                                <svg width=\"20\" height=\"27\" viewBox=\"0 0 20 27\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                                    <path\n                                        d=\"M18.6223 14.3857C19.1246 13.8975 19.1246 13.1045 18.6223 12.6162L12.1938 6.36621C11.6915 5.87793 10.8759 5.87793 10.3737 6.36621C9.87143 6.85449 9.87143 7.64746 10.3737 8.13574L14.6125 12.2529H2.28571C1.57455 12.2529 1 12.8115 1 13.5029C1 14.1943 1.57455 14.7529 2.28571 14.7529H14.6085L10.3777 18.8701C9.87545 19.3584 9.87545 20.1514 10.3777 20.6396C10.8799 21.1279 11.6955 21.1279 12.1978 20.6396L18.6263 14.3896L18.6223 14.3857Z\"\n                                        fill=\"#54B2D3\" \/>\n                                <\/svg>\n                            <\/div>\n                            <p><strong>Coding anesthesia for the hip instead?<\/strong> <a href=\"https:\/\/pabau.com\/procedure-codes\/cpt-code-01212\/\">CPT code 01212<\/a> sets out the base units and modifiers for hip disarticulation.<\/p>\n                        <\/div>\n                                                                                <div class=\"item\">\n                            <div>\n                                <svg width=\"20\" height=\"27\" viewBox=\"0 0 20 27\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                                    <path\n                                        d=\"M18.6223 14.3857C19.1246 13.8975 19.1246 13.1045 18.6223 12.6162L12.1938 6.36621C11.6915 5.87793 10.8759 5.87793 10.3737 6.36621C9.87143 6.85449 9.87143 7.64746 10.3737 8.13574L14.6125 12.2529H2.28571C1.57455 12.2529 1 12.8115 1 13.5029C1 14.1943 1.57455 14.7529 2.28571 14.7529H14.6085L10.3777 18.8701C9.87545 19.3584 9.87545 20.1514 10.3777 20.6396C10.8799 21.1279 11.6955 21.1279 12.1978 20.6396L18.6263 14.3896L18.6223 14.3857Z\"\n                                        fill=\"#54B2D3\" \/>\n                                <\/svg>\n                            <\/div>\n                            <p><strong>Billing anesthesia for a leg artery procedure?<\/strong> <a href=\"https:\/\/pabau.com\/procedure-codes\/cpt-code-01270\/\">CPT code 01270<\/a> walks through the femoral artery code and the documentation it needs.<\/p>\n                        <\/div>\n                                                                                <div class=\"item\">\n                            <div>\n                                <svg width=\"20\" height=\"27\" viewBox=\"0 0 20 27\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                                    <path\n                                        d=\"M18.6223 14.3857C19.1246 13.8975 19.1246 13.1045 18.6223 12.6162L12.1938 6.36621C11.6915 5.87793 10.8759 5.87793 10.3737 6.36621C9.87143 6.85449 9.87143 7.64746 10.3737 8.13574L14.6125 12.2529H2.28571C1.57455 12.2529 1 12.8115 1 13.5029C1 14.1943 1.57455 14.7529 2.28571 14.7529H14.6085L10.3777 18.8701C9.87545 19.3584 9.87545 20.1514 10.3777 20.6396C10.8799 21.1279 11.6955 21.1279 12.1978 20.6396L18.6263 14.3896L18.6223 14.3857Z\"\n                                        fill=\"#54B2D3\" \/>\n                                <\/svg>\n                            <\/div>\n                            <p><strong>Adjusting an external fixator between visits?<\/strong> <a href=\"https:\/\/pabau.com\/procedure-codes\/cpt-code-20697\/\">CPT code 20697<\/a> covers strut exchange billing and the notes that support it.<\/p>\n                        <\/div>\n                                                                                <div class=\"item\">\n                            <div>\n                                <svg width=\"20\" height=\"27\" viewBox=\"0 0 20 27\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                                    <path\n                                        d=\"M18.6223 14.3857C19.1246 13.8975 19.1246 13.1045 18.6223 12.6162L12.1938 6.36621C11.6915 5.87793 10.8759 5.87793 10.3737 6.36621C9.87143 6.85449 9.87143 7.64746 10.3737 8.13574L14.6125 12.2529H2.28571C1.57455 12.2529 1 12.8115 1 13.5029C1 14.1943 1.57455 14.7529 2.28571 14.7529H14.6085L10.3777 18.8701C9.87545 19.3584 9.87545 20.1514 10.3777 20.6396C10.8799 21.1279 11.6955 21.1279 12.1978 20.6396L18.6263 14.3896L18.6223 14.3857Z\"\n                                        fill=\"#54B2D3\" \/>\n                                <\/svg>\n                            <\/div>\n                            <p><strong>Charging for an ultrasound-guided joint injection?<\/strong> <a href=\"https:\/\/pabau.com\/procedure-codes\/cpt-code-20604\/\">CPT code 20604<\/a> explains how imaging guidance changes the code and the claim.<\/p>\n                        <\/div>\n                                                                                <div class=\"item\">\n                            <div>\n                                <svg width=\"20\" height=\"27\" viewBox=\"0 0 20 27\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\">\n                                    <path\n                                        d=\"M18.6223 14.3857C19.1246 13.8975 19.1246 13.1045 18.6223 12.6162L12.1938 6.36621C11.6915 5.87793 10.8759 5.87793 10.3737 6.36621C9.87143 6.85449 9.87143 7.64746 10.3737 8.13574L14.6125 12.2529H2.28571C1.57455 12.2529 1 12.8115 1 13.5029C1 14.1943 1.57455 14.7529 2.28571 14.7529H14.6085L10.3777 18.8701C9.87545 19.3584 9.87545 20.1514 10.3777 20.6396C10.8799 21.1279 11.6955 21.1279 12.1978 20.6396L18.6263 14.3896L18.6223 14.3857Z\"\n                                        fill=\"#54B2D3\" \/>\n                                <\/svg>\n                            <\/div>\n                            <p><strong>Running an orthopedic or sports practice?<\/strong> <a href=\"https:\/\/pabau.com\/blog\/7-sports-medicine-software\/\">Sports medicine software<\/a> compares the systems that keep notes, codes, and claims in one place.<\/p>\n                        <\/div>\n                                                <\/div>\n        <\/div>\n    \n\n\n<h2 class=\"wp-block-heading\">Frequently asked questions<\/h2>\n\n\n\n<div class=\"schema-faq wp-block-yoast-faq-block\"><div class=\"schema-faq-section\" id=\"faq-question-1785753216494\"><h3 class=\"schema-faq-question\">What is CPT code 01420 used for?<\/h3> <p class=\"schema-faq-answer\">CPT code 01420 reports anesthesia for cast application, removal, or repair involving the knee joint. The cast work is what the anesthesia covers. If the surgeon operated on the joint, the anesthesia code comes from the 01380 to 01404 range instead.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753216495\"><h3 class=\"schema-faq-question\">How many base units does CPT 01420 have?<\/h3> <p class=\"schema-faq-answer\">CPT code 01420 carries 3 base units in the ASA Relative Value Guide, and CMS adopts that value for Medicare. Any fee schedule holding 4 base units for this code has it confused with 01400.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753216496\"><h3 class=\"schema-faq-question\">Which code should I use for knee surgery anesthesia instead of 01420?<\/h3> <p class=\"schema-faq-answer\">Use 01380 for closed procedures on the knee joint at 3 base units. 01400 covers open or arthroscopic procedures at 4 units, and 01402 total knee arthroplasty at 7. 01404 covers disarticulation at the knee at 5 units, and 01382 diagnostic knee arthroscopy at 3.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753216497\"><h3 class=\"schema-faq-question\">How do you calculate total anesthesia units for CPT code 01420?<\/h3> <p class=\"schema-faq-answer\">Total units are 3 base units plus time units plus any qualifying circumstance units. Most payers count 1 time unit per 15 minutes of anesthesia time, though some use 10 minutes. A 45-minute cast application gives 3 time units, for 6 total units.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753216498\"><h3 class=\"schema-faq-question\">What modifiers apply to CPT code 01420?<\/h3> <p class=\"schema-faq-answer\">Every 01420 claim needs a physical status modifier from P1 through P6 and a provider-role modifier. The provider-role options are AA for a personally performed service and QK for medical direction of 2 to 4 concurrent cases. QX covers a medically directed CRNA, QY one directed CRNA, and QZ a CRNA without medical direction.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753216499\"><h3 class=\"schema-faq-question\">What ICD-10 codes pair with CPT code 01420?<\/h3> <p class=\"schema-faq-answer\">Pair it with diagnoses that explain the cast. S82.001A covers an initial closed fracture of the right patella, and S82.101A the upper end of the right tibia. S72.401A covers the lower end of the right femur. M24.561 is a right knee contracture, and Z47.89 is other orthopedic aftercare. Osteoarthritis and ligament tear codes belong on surgical anesthesia claims.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753216500\"><h3 class=\"schema-faq-question\">What is the Medicare reimbursement for CPT code 01420?<\/h3> <p class=\"schema-faq-answer\">Payment equals total anesthesia units multiplied by the CMS anesthesia conversion factor for the locality. The national figures are $20.4349 for 2024 and $20.3178 for 2025. For 2026, CMS finalized $20.4976 for most clinicians and $20.5998 for qualifying Advanced Alternative Payment Model participants. A 45-minute case at 6 units and the 2024 national rate comes to about $122.61.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753216501\"><h3 class=\"schema-faq-question\">Can you bill 01420 when a cast is applied at the end of knee surgery?<\/h3> <p class=\"schema-faq-answer\">No. The surgical anesthesia code already covers the whole anesthesia period, including the cast that goes on before the patient wakes. Adding 01420 on top of it is duplicate billing. Report 01420 only when the cast work is the reason for the anesthesia.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753216502\"><h3 class=\"schema-faq-question\">Which qualifying circumstance codes can be billed with CPT code 01420?<\/h3> <p class=\"schema-faq-answer\">99100 for extreme age carries 1 unit and often applies, since many knee cast cases are pediatric. 99140 for emergency conditions carries 2 units. 99116 for total body hypothermia and 99135 for controlled hypotension carry 5 units each but are not clinically plausible here. Traditional Medicare bundles all four rather than paying them separately.<\/p> <\/div> <\/div>\n\n","protected":false},"excerpt":{"rendered":"<p>CPT code 01420 covers anesthesia for cast work on the knee, not knee surgery. The official descriptor is Anesthesia for all cast applications, removal, or repair involving knee joint. The procedure being anesthetized is the cast. That&#8217;s easy to miss, because the code sits in the middle of the knee surgery series and reads like [&hellip;]<\/p>\n","protected":false},"author":81,"featured_media":171293,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_yoast_wpseo_linkdex":"","_yoast_wpseo_content_score":"","_yoast_wpseo_is_cornerstone":"","_yoast_wpseo_keywordsynonyms":"","_yoast_wpseo_focuskw_text_input":"","_seo_original_html":"","footnotes":""},"categories":[1433,1546],"tags":[],"class_list":["post-171294","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-billing-codes","category-cpt-codes"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v28.2 (Yoast SEO v28.2) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>CPT code 01420: Anesthesia for knee cast procedures<\/title>\n<meta name=\"description\" content=\"CPT code 01420 covers anesthesia for knee cast application, removal, or repair. 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If the surgeon operated on the joint, the anesthesia code comes from the 01380 to 01404 range instead.","inLanguage":"es"},"inLanguage":"es"},{"@type":"Question","@id":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216495","position":2,"url":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216495","name":"How many base units does CPT 01420 have?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"CPT code 01420 carries 3 base units in the ASA Relative Value Guide, and CMS adopts that value for Medicare. 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Most payers count 1 time unit per 15 minutes of anesthesia time, though some use 10 minutes. A 45-minute cast application gives 3 time units, for 6 total units.","inLanguage":"es"},"inLanguage":"es"},{"@type":"Question","@id":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216498","position":5,"url":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216498","name":"What modifiers apply to CPT code 01420?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"Every 01420 claim needs a physical status modifier from P1 through P6 and a provider-role modifier. The provider-role options are AA for a personally performed service and QK for medical direction of 2 to 4 concurrent cases. QX covers a medically directed CRNA, QY one directed CRNA, and QZ a CRNA without medical direction.","inLanguage":"es"},"inLanguage":"es"},{"@type":"Question","@id":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216499","position":6,"url":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216499","name":"What ICD-10 codes pair with CPT code 01420?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"Pair it with diagnoses that explain the cast. S82.001A covers an initial closed fracture of the right patella, and S82.101A the upper end of the right tibia. S72.401A covers the lower end of the right femur. M24.561 is a right knee contracture, and Z47.89 is other orthopedic aftercare. Osteoarthritis and ligament tear codes belong on surgical anesthesia claims.","inLanguage":"es"},"inLanguage":"es"},{"@type":"Question","@id":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216500","position":7,"url":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216500","name":"What is the Medicare reimbursement for CPT code 01420?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"Payment equals total anesthesia units multiplied by the CMS anesthesia conversion factor for the locality. The national figures are $20.4349 for 2024 and $20.3178 for 2025. For 2026, CMS finalized $20.4976 for most clinicians and $20.5998 for qualifying Advanced Alternative Payment Model participants. A 45-minute case at 6 units and the 2024 national rate comes to about $122.61.","inLanguage":"es"},"inLanguage":"es"},{"@type":"Question","@id":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216501","position":8,"url":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216501","name":"Can you bill 01420 when a cast is applied at the end of knee surgery?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"No. The surgical anesthesia code already covers the whole anesthesia period, including the cast that goes on before the patient wakes. Adding 01420 on top of it is duplicate billing. Report 01420 only when the cast work is the reason for the anesthesia.","inLanguage":"es"},"inLanguage":"es"},{"@type":"Question","@id":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216502","position":9,"url":"https:\/\/pabau.com\/es\/procedure-codes\/cpt-code-01420\/#faq-question-1785753216502","name":"Which qualifying circumstance codes can be billed with CPT code 01420?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"99100 for extreme age carries 1 unit and often applies, since many knee cast cases are pediatric. 99140 for emergency conditions carries 2 units. 99116 for total body hypothermia and 99135 for controlled hypotension carry 5 units each but are not clinically plausible here. Traditional Medicare bundles all four rather than paying them separately.","inLanguage":"es"},"inLanguage":"es"}]}},"yoast":{"focus_keyword":"CPT code 01420","seo_title":"CPT code 01420: Anesthesia for knee cast procedures","meta_description":"CPT code 01420 covers anesthesia for knee cast application, removal, or repair. Get the 3 base units, modifiers, and ICD-10 pairings.","content_score":"","is_cornerstone":"","related_keyphrases":[{"keyword":"anesthesia base units calculation","synonyms":["CPT 01420","01420 CPT code description","CPT code 01420 anesthesia knee","01420 anesthesia base units"]},{"keyword":"physical status modifiers anesthesia","synonyms":["CPT 01420","01420 CPT code description","CPT code 01420 anesthesia knee","01420 anesthesia base units"]},{"keyword":"Medicare anesthesia reimbursement rates","synonyms":["CPT 01420","01420 CPT code description","CPT code 01420 anesthesia knee","01420 anesthesia base units"]}]},"_links":{"self":[{"href":"https:\/\/pabau.com\/es\/wp-json\/wp\/v2\/posts\/171294","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pabau.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pabau.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pabau.com\/es\/wp-json\/wp\/v2\/users\/81"}],"replies":[{"embeddable":true,"href":"https:\/\/pabau.com\/es\/wp-json\/wp\/v2\/comments?post=171294"}],"version-history":[{"count":4,"href":"https:\/\/pabau.com\/es\/wp-json\/wp\/v2\/posts\/171294\/revisions"}],"predecessor-version":[{"id":182013,"href":"https:\/\/pabau.com\/es\/wp-json\/wp\/v2\/posts\/171294\/revisions\/182013"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pabau.com\/es\/wp-json\/wp\/v2\/media\/171293"}],"wp:attachment":[{"href":"https:\/\/pabau.com\/es\/wp-json\/wp\/v2\/media?parent=171294"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pabau.com\/es\/wp-json\/wp\/v2\/categories?post=171294"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pabau.com\/es\/wp-json\/wp\/v2\/tags?post=171294"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}