{"id":171318,"date":"2026-08-03T13:56:05","date_gmt":"2026-08-03T13:56:05","guid":{"rendered":"https:\/\/pabau.com\/?p=171318"},"modified":"2026-08-17T12:29:43","modified_gmt":"2026-08-17T12:29:43","slug":"icd-10-code-m456","status":"publish","type":"post","link":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/","title":{"rendered":"ICD-10 Code M45.6: Ankylosing spondylitis lumbar region"},"content":{"rendered":"\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"MedicalWebPage\",\"headline\":\"ICD-10 Code M45.6: Ankylosing spondylitis lumbar region\",\"description\":\"ICD-10 Code M45.6 covers ankylosing spondylitis of the lumbar region. Learn its billable status, the M45 sibling codes, the M45.A series for non-radiographic axSpA, documentation requirements, excludes notes, and the ICD-9 crosswalk.\",\"url\":\"https:\/\/pabau.com\/diagnostic-codes\/icd-10-code-m456\/\",\"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\":\"2026-08-03\",\"dateModified\":\"2026-08-03\"}<\/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>ICD-10 code M45.6 is the billable ICD-10-CM diagnosis code for ankylosing spondylitis of the lumbar region, valid for FY2026 claims.<\/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 FY2026 edition took effect on October 1, 2025. Always confirm the current fiscal year before you submit.<\/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>Using M45.9 for unspecified site when the lumbar region is documented is a common and auditable coding error.<\/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>Non-radiographic axial spondyloarthritis has its own codes inside M45, the M45.A series, so M46.x is the wrong destination.<\/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 ties the documented spinal region to the claim, so specificity errors surface before submission.<\/p>\n                        <\/div>\n                                                <\/div>\n        <\/div>\n    \n\n\n<p class=\"wp-block-paragraph\">ICD-10 Code M45.6 is the billable ICD-10-CM diagnosis code for <strong>ankylosing spondylitis of the lumbar region<\/strong>. Use it when the physician confirms ankylosing spondylitis and names the lumbar spine as the affected site. When the note records no site at all, M45.9 is the fallback.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This reference covers the code&#8217;s description and billable status, the full M45 sibling table, documentation requirements, excludes notes, common pitfalls, and the ICD-9 crosswalk. It is written for medical coders, rheumatology practices, and physical therapists who document inflammatory spinal conditions.<\/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=\"ICD-10 Revisions: Stay Updated or Fall Behind\" width=\"800\" height=\"450\" src=\"https:\/\/www.youtube.com\/embed\/bqAyb-BCA0w?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\">ICD-10 Code M45.6: Definition and billable status<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">M45.6 is valid for use in FY2026 claims and became effective on October 1, 2025 under the <a href=\"https:\/\/www.cms.gov\/medicare\/coding-billing\/icd-10-codes\" target=\"_blank\" rel=\"nofollow noopener\">CMS annual ICD-10-CM update<\/a>. The code comes from the International Classification of Diseases, 10th Revision, Clinical Modification. That US adaptation is maintained jointly by CMS and the National Center for Health Statistics under HIPAA.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ankylosing spondylitis (AS) is a chronic inflammatory arthritis that mainly affects the axial skeleton. The lumbar spine is one of the most common sites of clinical involvement. That makes M45.6 one of the most frequently used codes in the M45 category. Below is the at-a-glance reference for this code.<\/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<\/td>\n<td style=\"padding:12px 16px;color:#374151\">M45.6<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Official description<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis lumbar region<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Billable\/specific<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Yes, valid for reimbursement<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Parent code<\/td>\n<td style=\"padding:12px 16px;color:#374151\">M45 (Ankylosing spondylitis)<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">ICD-10-CM chapter<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Block<\/td>\n<td style=\"padding:12px 16px;color:#374151\">M45-M49 (Spondylopathies)<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">FY2026 effective date<\/td>\n<td style=\"padding:12px 16px;color:#374151\">October 1, 2025<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Valid for submission<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Yes<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<h2 class=\"wp-block-heading\">Clinical overview: ankylosing spondylitis of the lumbar region<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Ankylosing spondylitis is a seronegative spondyloarthropathy marked by chronic inflammation of the spinal and sacroiliac joints. It leads to progressive ankylosis, or fusion, of vertebral segments over time. The lumbar spine is often the first or most prominently affected region. Patients present with inflammatory back pain that is worse at rest and improves with movement.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Region coding matters because AS can affect several spinal segments, and payers expect the submitted code to match the documented site. A note that says only &#8220;ankylosing spondylitis&#8221; leaves the coder with no basis for anything more specific than M45.9. For physical therapy EMR users treating musculoskeletal patients, region-specific documentation from the referring clinician is what drives accurate code selection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Key clinical indicators that support the M45.6 diagnosis:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Confirmed diagnosis of ankylosing spondylitis by a rheumatologist or treating physician<\/li><li>Documented lumbar region as the primary or most affected spinal site<\/li><li>Inflammatory back pain lasting more than three months, beginning before age 45<\/li><li>Evidence of sacroiliitis on imaging, whether X-ray or MRI, or HLA-B27 positivity<\/li><li>Clinical response to NSAIDs, supporting an inflammatory rather than mechanical etiology<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">HLA-B27 positivity appears in roughly 90% of AS patients, according to the NIH&#8217;s <a href=\"https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK551523\/\" target=\"_blank\" rel=\"nofollow noopener\">StatPearls review<\/a>. Its presence supports the diagnosis but does not replace physician documentation of confirmed AS in the lumbar region. A coder cannot infer M45.6 from a positive marker alone.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">M45.6 within the M45 code category: sibling codes by spinal region<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">ICD-10 Code M45.6 sits within the M45 category, which covers ankylosing spondylitis across all spinal regions. The parent code M45 is not billable on its own. Coders select the 4th-character subcode that matches the documented spinal region. The <a href=\"https:\/\/icd10cmtool.cdc.gov\/\" target=\"_blank\" rel=\"nofollow noopener\">CDC\/NCHS ICD-10-CM web tool<\/a> lists every valid M45 code for the current fiscal 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\">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:center;font-weight:600;font-size:14px;letter-spacing:0.3px;border-bottom:2px solid #2BADD4\">Billable<\/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\">M45.0<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis of multiple sites in spine<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">Yes<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M45.1<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis of occipito-atlanto-axial region<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">Yes<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M45.2<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis of cervical region<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">Yes<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M45.3<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis of cervicothoracic region<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">Yes<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M45.4<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis of thoracic region<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">Yes<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M45.5<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis of thoracolumbar region<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">Yes<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#2BADD4;font-size:15px\">M45.6<\/td>\n<td style=\"padding:12px 16px;color:#121D36;font-weight:600\">Ankylosing spondylitis lumbar region (this code)<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">Yes<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M45.7<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis of lumbosacral region<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">Yes<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M45.8<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis sacral and sacrococcygeal region<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">Yes<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M45.9<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis of unspecified sites in spine<\/td>\n<td style=\"padding:12px 16px;text-align:center;color:#374151\">Yes<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">When AS affects both the lumbar region (L1-L5) and the lumbosacral junction, the correct code shifts to M45.7. When documentation confirms involvement at multiple distinct spinal levels, M45.0 applies. M45.9 covers an unspecified site only, never a site that is known but left out of the note.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The M45 category also carries the M45.A series for non-radiographic axial spondyloarthritis, added effective October 1, 2021. Those codes follow the same regional pattern, so M45.A6 is the lumbar entry. They are not interchangeable with M45.6, which requires radiographic AS.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">ICD-10-CM documentation requirements for M45.6<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Payers expect the clinical record to substantiate every element of a submitted diagnosis code. For M45.6, the documentation must establish both the diagnosis and the anatomical site. Maintaining structured client records with diagnosis-specific fields reduces the risk of medical necessity denials.<\/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\/diagnostic_codes\/icd-10-code-m456\/detailed-client-records-in-pabau.webp\" alt=\"Detailed client records in Pabau\"\/><figcaption class=\"wp-element-caption\"><em>Pabau&#8217;s client record keeps medical history, medications, and test results on one screen, so the documented lumbar diagnosis is easy to verify.<\/em><\/figcaption><\/figure>\n\n\n\n<div style=\"height:35px;width:800px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">The <a href=\"https:\/\/www.aapc.com\/codes\/icd-10-codes-range\/\" target=\"_blank\" rel=\"nofollow noopener\">AAPC ICD-10-CM coding guidelines<\/a> reinforce one rule above all others. The physician must document both the confirmed diagnosis and the affected region, and coders cannot infer either element.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>Confirmed diagnosis statement:<\/strong> the treating physician, usually a rheumatologist, must explicitly state &#8220;ankylosing spondylitis.&#8221; A working diagnosis or rule-out language does not support coding.<\/li><li><strong>Lumbar region specificity:<\/strong> the note must identify the lumbar spine (L1-L5 vertebrae) as the affected site. &#8220;Low back pain&#8221; or &#8220;back pain&#8221; alone is insufficient.<\/li><li><strong>Supporting clinical evidence:<\/strong> imaging findings, inflammatory markers, or a history consistent with AS can be documented to support medical necessity.<\/li><li><strong>HLA-B27 status:<\/strong> when recorded, HLA-B27 positivity strengthens the clinical picture but does not replace the physician&#8217;s diagnostic statement.<\/li><li><strong>Chronicity:<\/strong> documentation should reflect the chronic, progressive nature of the condition for ongoing visit coding.<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Practices running practice management software can build note templates with a mandatory diagnosis and site field. That prompts clinicians to capture what coders need, which cuts query volume and shortens billing cycles.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Excludes notes and coding restrictions for M45.6<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">ICD-10-CM uses two types of excludes notes, and they carry different coding implications. Getting them wrong produces unbundling errors or false claim submissions. Using compliance management tools inside your EHR helps flag excludes conflicts before submission.<\/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\/diagnostic_codes\/icd-10-code-m456\/hipaa-compliance-in-pabau.webp\" alt=\"HIPAA compliance in Pabau\"\/><figcaption class=\"wp-element-caption\"><em>Pabau&#8217;s security tools enforce two-factor authentication and HIPAA settings, so the notes that support an M45.6 claim stay protected.<\/em><\/figcaption><\/figure>\n\n\n\n<div style=\"height:35px;width:800px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\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\">Note 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 it means<\/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\">Practical rule<\/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\">Excludes1<\/td>\n<td style=\"padding:12px 16px;color:#374151\">A true exclusion. The excluded condition cannot coexist with the coded condition at the same anatomical site.<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Do not assign both codes at once.<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Excludes2<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Not included here. The excluded condition is a different condition that may coexist and be coded separately.<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Both codes may be assigned when documented.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">For the M45 category, the key Excludes1 note covers arthropathy in Reiter&#8217;s disease (M02.3-). Coders must not assign M45.6 alongside reactive arthritis codes when the spondylitis is attributable to Reiter&#8217;s disease rather than primary AS. If the record describes both conditions at different anatomical sites, query the physician before proceeding.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Non-radiographic axial spondyloarthritis (nr-axSpA) is not coded to M45.6, but it does sit inside the M45 category. ICD-10-CM added dedicated M45.A subcodes for it, effective October 1, 2021, running from M45.A0 through M45.A9. For lumbar nr-axSpA, that code is M45.A6. Reaching for M46.x instead is a coding error, not a conservative choice.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Common coding errors to avoid with ICD-10 Code M45.6<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Coding audits for ankylosing spondylitis claims surface the same mistakes again and again. The list below reflects patterns that show up in rheumatology audits and in wider medical billing reviews. Catching them before submission is faster than appealing a denial.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>Using M45.9 when the lumbar region is documented.<\/strong> This is the most common error. If the physician has specified the lumbar spine, M45.6 is the correct code. M45.9 is for cases where no site has been documented, not for administrative convenience.<\/li><li><strong>Confusing M45.6 with M54.5 for low back pain.<\/strong> Low back pain is a symptom code, in the same family as M54.2. Ankylosing spondylitis is a confirmed diagnosis, so submitting M54.5 for a documented AS patient under-codes the condition.<\/li><li><strong>Coding non-radiographic axSpA as M45.6.<\/strong> Without radiographic confirmation, the M45.A subcodes apply, and M45.A6 covers the lumbar region. Check the physician&#8217;s documented certainty level before selecting M45.6.<\/li><li><strong>Assuming HLA-B27 positivity supports M45.6 on its own.<\/strong> HLA-B27 is a risk marker, not a diagnosis. The physician must document confirmed AS affecting the lumbar region for M45.6 to be valid.<\/li><li><strong>Omitting the lumbar qualifier for multi-site AS.<\/strong> When AS affects several documented spinal regions including the lumbar spine, M45.0 may be more accurate than M45.6. Review the full clinical note before defaulting to the lumbar-specific code.<\/li><\/ul>\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 on your M45.x submissions. Pull every claim coded M45.9 and cross-check it against the clinical note. Any case with a documented spinal site should be recoded to the region-specific M45.x variant. That one correction resolves most specificity-related denials in rheumatology billing.<\/p>\n            <\/div>\n        <\/div>\n    \n\n\n<h2 class=\"wp-block-heading\">ICD-9 to ICD-10 crosswalk for M45.6<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Practices that keep legacy claims data or process late submissions for prior periods sometimes need to cross-reference ICD-9-CM against ICD-10-CM. The General Equivalence Mappings (GEMs), documented by <a href=\"https:\/\/resdac.org\/articles\/international-classification-disease-icd-codes-medicare-files\" target=\"_blank\" rel=\"nofollow noopener\">ResDAC<\/a>, provide the official crosswalk framework. ICD-10-CM offers greater anatomical specificity than ICD-9-CM, so the conversion is approximate.<\/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-9-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\">ICD-9 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\">ICD-10-CM equivalent<\/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\">Notes<\/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\">720.0<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis<\/td>\n<td style=\"padding:12px 16px;color:#374151\">M45.6 (and other M45 codes)<\/td>\n<td style=\"padding:12px 16px;color:#374151\">ICD-9 did not specify spinal region. ICD-10-CM requires site selection.<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">720.0<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Ankylosing spondylitis<\/td>\n<td style=\"padding:12px 16px;color:#374151\">M45.9<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Used only when ICD-9 documentation lacked any regional specification.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">ICD-9-CM 720.0 mapped to every ankylosing spondylitis diagnosis without distinguishing spinal level. Under ICD-10-CM, that single code fans out across ten M45 subcodes based on the documented site. When converting legacy records, review the original clinical note to assign the right regional subcode. Defaulting to M45.9 without that review is inaccurate.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Related diagnoses and co-occurring conditions<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Ankylosing spondylitis rarely presents in isolation. Coders working with AS patients meet co-occurring and differential diagnoses, from degenerative disease such as M17.5 to systemic inflammatory conditions such as M35.2.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For practices that run on <a href=\"https:\/\/pabau.com\/industry\/sports-medicine-software\/\">sports medicine software<\/a>, musculoskeletal comorbidities are especially common. The same patient may carry an inflammatory diagnosis and a mechanical injury, and each documented condition gets its own code.<\/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\">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\">Relationship to M45.6<\/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\">M46.1<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Sacroiliitis, not elsewhere classified<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Common early feature of AS. Code it alongside M45.6 when clinically distinct.<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M46.80<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Other specified inflammatory spondylopathies, site unspecified<\/td>\n<td style=\"padding:12px 16px;color:#374151\">For inflammatory spondylopathies that are not AS. Non-radiographic axSpA belongs in M45.A, not here.<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M77.30<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Calcaneal spur, unspecified foot<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Enthesopathy frequently co-occurs with AS. Code it separately when documented.<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">M47.816<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Spondylosis without myelopathy or radiculopathy, lumbar region<\/td>\n<td style=\"padding:12px 16px;color:#374151\">A differential. Spondylosis is degenerative rather than inflammatory, so distinguish it from AS in the note.<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">L40.53<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Psoriatic spondylitis<\/td>\n<td style=\"padding:12px 16px;color:#374151\">A separate spondyloarthropathy. It requires psoriasis documentation, so do not use M45.6.<\/td>\n<\/tr>\n<tr style=\"border-bottom:1px solid #E8ECF0;background:#F9FAFB\">\n<td style=\"padding:12px 16px;font-weight:600;color:#121D36\">Z13.828<\/td>\n<td style=\"padding:12px 16px;color:#374151\">Encounter for screening for musculoskeletal disorder<\/td>\n<td style=\"padding:12px 16px;color:#374151\">May appear on preventive visits while AS is being worked up.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<h2 class=\"wp-block-heading\">Related ICD-10 codes<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/pabau.com\/diagnostic-codes\/icd-10-code-m5126\/\">ICD-10 code M51.26 \u2014 Lumbar Disc Displacement<\/a><\/li>\n\n\n<li><a href=\"https:\/\/pabau.com\/diagnostic-codes\/icd-10-code-m457\/\">ICD-10 Code M45.7 \u2014 Ankylosing spondylitis of lumbosacral region<\/a><\/li>\n\n\n<li><a href=\"https:\/\/pabau.com\/diagnostic-codes\/icd-10-code-m458\/\">ICD-10 Code M45.8 \u2014 Ankylosing spondylitis of the sacral region<\/a><\/li>\n\n\n<li><a href=\"https:\/\/pabau.com\/diagnostic-codes\/icd-10-code-m459\/\">ICD-10 M45.9 \u2014 Ankylosing spondylitis, unspecified spine<\/a><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">How Pabau supports ICD-10 diagnostic coding workflows<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Accurate diagnosis coding starts in the clinical note, long before a claim is submitted. When documentation is structured and linked to billing, what the physician records and what the coder submits stay in step. Practice management software like Pabau is built for that handoff.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pabau&#8217;s claims management software connects clinical documentation to the billing workflow, so fewer manual handoffs sit between the note and the claim. Practices can build condition-specific note templates that prompt clinicians to record the affected spinal region alongside the confirmed diagnosis. Coders working on M45.6 claims then have what they need without raising a query.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a lumbar AS workup, that detail is what supports the site-specific code 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\/diagnostic_codes\/icd-10-code-m456\/fully-integrated-with-pabau-billing.webp\" alt=\"Fully integrated with Pabau billing\"\/><figcaption class=\"wp-element-caption\"><em>Pabau matches insurer remittances line by line, so a reissued or unpaid M45.6 claim surfaces before it ages out.<\/em><\/figcaption><\/figure>\n\n\n\n<div style=\"height:35px;width:800px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">For rheumatology and musculoskeletal practices managing chronic conditions like AS, the returns compound over time. Fewer denials, faster resubmissions, and cleaner audit trails all follow from one accurate note. <\/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>Build a lumbar AS note template with a mandatory field for spinal region. A rheumatologist who records &#8216;ankylosing spondylitis, lumbar spine affected&#8217; in a structured field gives the coder everything M45.6 needs, with no query. One template, zero ambiguity.<\/p>\n            <\/div>\n        <\/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                    See how Pabau supports diagnostic coding workflows                <\/h3>\n\n                <p class=\"description\">\n                    Connect clinical documentation to billing in one platform. Reduce M45.6 denials with structured note templates and integrated claims management.                <\/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 practice management platform 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\">The only thing standing between M45.6 and a denial is a note that names both the diagnosis and the lumbar spine. Build that habit into the record and code selection takes care of itself.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If your practice codes AS regularly, start with the note template rather than a tighter review step. A mandatory site field costs a clinician two seconds and saves the coder a query. <a href=\"https:\/\/pabau.com\/book-demo\/\">Book a demo<\/a> to see how Pabau links lumbar AS documentation to the claim that follows.<\/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 another systemic inflammatory diagnosis?<\/strong> <a href=\"https:\/\/pabau.com\/diagnostic-codes\/icd-10-code-m310\/\">M31.0<\/a> walks through hypersensitivity angiitis and the documentation payers expect on vasculitis claims.<\/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>Need the necrotizing vasculopathy codes?<\/strong> <a href=\"https:\/\/pabau.com\/diagnostic-codes\/icd-10-code-m318\/\">M31.8<\/a> sets out what belongs in the other specified category and what does not.<\/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>Separating degenerative arthritis from inflammatory disease?<\/strong> <a href=\"https:\/\/pabau.com\/diagnostic-codes\/icd-10-code-m184\/\">M18.4<\/a> explains secondary osteoarthritis coding at the first carpometacarpal joints.<\/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>Documenting a lumbar or sacral nerve injury?<\/strong> <a href=\"https:\/\/pabau.com\/diagnostic-codes\/icd-10-code-s345xxa\/\">S34.5XXA<\/a> covers initial-encounter coding for the lumbar, sacral, and pelvic sympathetic nerves.<\/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>Seeing jaw involvement in a spondyloarthritis patient?<\/strong> <a href=\"https:\/\/pabau.com\/diagnostic-codes\/icd-10-code-m279\/\">M27.9<\/a> explains when an unspecified jaw diagnosis is defensible.<\/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-1785753250169\"><h3 class=\"schema-faq-question\">What is ICD-10 Code M45.6?<\/h3> <p class=\"schema-faq-answer\">ICD-10 Code M45.6 is the billable ICD-10-CM diagnosis code for ankylosing spondylitis of the lumbar region. It is valid for FY2026 claims, became effective October 1, 2025, and falls under Chapter 13 of ICD-10-CM (diseases of the musculoskeletal system, M00-M99).<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753250170\"><h3 class=\"schema-faq-question\">Is M45.6 a billable ICD-10-CM code?<\/h3> <p class=\"schema-faq-answer\">Yes. M45.6 is a billable and specific ICD-10-CM code valid for use in FY2026 diagnosis and reimbursement submissions. It requires physician documentation of confirmed ankylosing spondylitis with the lumbar region identified as the affected site.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753250171\"><h3 class=\"schema-faq-question\">What is the difference between M45.6 and M45.9?<\/h3> <p class=\"schema-faq-answer\">M45.6 specifies ankylosing spondylitis of the lumbar region. M45.9 is used only when no spinal site has been documented. When the lumbar region is recorded in the clinical note, M45.6 is the correct code. Using M45.9 for a documented lumbar case is a common specificity error that invites payer scrutiny.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753250172\"><h3 class=\"schema-faq-question\">What documentation is required to use ICD-10 Code M45.6?<\/h3> <p class=\"schema-faq-answer\">The physician must explicitly document a confirmed ankylosing spondylitis diagnosis and identify the lumbar spine as the affected region. Supporting evidence such as imaging findings, HLA-B27 status, or inflammatory markers strengthens the clinical record but does not replace the diagnostic statement.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753250173\"><h3 class=\"schema-faq-question\">Is axial spondyloarthritis coded the same as ankylosing spondylitis?<\/h3> <p class=\"schema-faq-answer\">No. Ankylosing spondylitis with radiographic confirmation maps to M45 codes, including M45.6. Non-radiographic axial spondyloarthritis has its own subcodes inside M45, the M45.A series, with M45.A6 covering the lumbar region. Verify the physician&#8217;s documented imaging evidence before selecting M45.6.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1785753250174\"><h3 class=\"schema-faq-question\">What was the ICD-9 equivalent of M45.6?<\/h3> <p class=\"schema-faq-answer\">The closest ICD-9-CM equivalent is 720.0 (Ankylosing spondylitis). ICD-9-CM did not distinguish between spinal regions, so a single code mapped to all AS diagnoses. Under ICD-10-CM, 720.0 converts to multiple M45 subcodes depending on the documented spinal site. Converting legacy claims requires reviewing the original clinical note rather than defaulting to M45.9.<\/p> <\/div> <\/div>\n\n","protected":false},"excerpt":{"rendered":"<p>ICD-10 Code M45.6 is the billable ICD-10-CM diagnosis code for ankylosing spondylitis of the lumbar region. Use it when the physician confirms ankylosing spondylitis and names the lumbar spine as the affected site. When the note records no site at all, M45.9 is the fallback. This reference covers the code&#8217;s description and billable status, the [&hellip;]<\/p>\n","protected":false},"author":81,"featured_media":171317,"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":[1433,1549,1550,1125],"tags":[1586,1363,1305,2635,3655],"class_list":["post-171318","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-billing-codes","category-diagnostic-codes","category-icd-10-cm","category-musculoskeletal-pain-management","tag-billing-guide","tag-icd-10","tag-icd-10-codes","tag-rheumatology-coding","tag-spine-coding"],"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>ICD-10 Code M45.6: Lumbar ankylosing spondylitis billing 2026<\/title>\n<meta name=\"description\" content=\"M45.6 is the billable ICD-10-CM code for ankylosing spondylitis of the lumbar region. Non-radiographic axSpA belongs in M45.A, not M46.x.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/\" \/>\n<meta property=\"og:locale\" content=\"nl_NL\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"ICD-10 Code M45.6: Lumbar ankylosing spondylitis billing 2026\" \/>\n<meta property=\"og:description\" content=\"M45.6 is the billable ICD-10-CM code for ankylosing spondylitis of the lumbar region. Non-radiographic axSpA belongs in M45.A, not M46.x.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/\" \/>\n<meta property=\"og:site_name\" content=\"Pabau\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/Pabau\/\" \/>\n<meta property=\"article:published_time\" content=\"2026-08-03T13:56:05+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-08-17T12:29:43+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/pabau.com\/wp-content\/uploads\/2026\/08\/icd-10-code-m456.webp\" \/>\n\t<meta property=\"og:image:width\" content=\"1200\" \/>\n\t<meta property=\"og:image:height\" content=\"630\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/webp\" \/>\n<meta name=\"author\" content=\"Aleksandar Kochovski\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@pabaucrm\" \/>\n<meta name=\"twitter:site\" content=\"@pabaucrm\" \/>\n<meta name=\"twitter:label1\" content=\"Geschreven door\" \/>\n\t<meta name=\"twitter:data1\" content=\"Aleksandar Kochovski\" \/>\n\t<meta name=\"twitter:label2\" content=\"Geschatte leestijd\" \/>\n\t<meta name=\"twitter:data2\" content=\"12 minuten\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/\"},\"author\":{\"name\":\"Aleksandar Kochovski\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/#\\\/schema\\\/person\\\/73b672a49e20bfba8161e3c17ee3dda2\"},\"headline\":\"ICD-10 Code M45.6: Ankylosing spondylitis lumbar region\",\"datePublished\":\"2026-08-03T13:56:05+00:00\",\"dateModified\":\"2026-08-17T12:29:43+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/\"},\"wordCount\":2321,\"publisher\":{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/pabau.com\\\/wp-content\\\/uploads\\\/2026\\\/08\\\/icd-10-code-m456.webp\",\"keywords\":[\"Billing Guide\",\"ICD-10\",\"ICD-10 codes\",\"Rheumatology coding\",\"Spine Coding\"],\"articleSection\":[\"Billing Codes\",\"Diagnostic Codes\",\"ICD-10-CM\",\"Musculoskeletal &amp; Pain Management\"],\"inLanguage\":\"nl-NL\"},{\"@type\":[\"WebPage\",\"FAQPage\"],\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/\",\"url\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/\",\"name\":\"ICD-10 Code M45.6: Lumbar ankylosing spondylitis billing 2026\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/pabau.com\\\/wp-content\\\/uploads\\\/2026\\\/08\\\/icd-10-code-m456.webp\",\"datePublished\":\"2026-08-03T13:56:05+00:00\",\"dateModified\":\"2026-08-17T12:29:43+00:00\",\"description\":\"M45.6 is the billable ICD-10-CM code for ankylosing spondylitis of the lumbar region. Non-radiographic axSpA belongs in M45.A, not M46.x.\",\"mainEntity\":[{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250169\"},{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250170\"},{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250171\"},{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250172\"},{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250173\"},{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250174\"}],\"inLanguage\":\"nl-NL\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"nl-NL\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#primaryimage\",\"url\":\"https:\\\/\\\/pabau.com\\\/wp-content\\\/uploads\\\/2026\\\/08\\\/icd-10-code-m456.webp\",\"contentUrl\":\"https:\\\/\\\/pabau.com\\\/wp-content\\\/uploads\\\/2026\\\/08\\\/icd-10-code-m456.webp\",\"width\":1200,\"height\":630},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/#website\",\"url\":\"https:\\\/\\\/pabau.com\\\/nl\\\/\",\"name\":\"Pabau\",\"description\":\"Clinic Software for your Business | Go Paperless Today\",\"publisher\":{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/pabau.com\\\/nl\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"nl-NL\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/#organization\",\"name\":\"Pabau\",\"url\":\"https:\\\/\\\/pabau.com\\\/nl\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"nl-NL\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/pabau.com\\\/wp-content\\\/uploads\\\/2022\\\/05\\\/Logo-4-e1654525062364.png\",\"contentUrl\":\"https:\\\/\\\/pabau.com\\\/wp-content\\\/uploads\\\/2022\\\/05\\\/Logo-4-e1654525062364.png\",\"width\":736,\"height\":195,\"caption\":\"Pabau\"},\"image\":{\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/Pabau\\\/\",\"https:\\\/\\\/x.com\\\/pabaucrm\",\"https:\\\/\\\/www.linkedin.com\\\/company\\\/pabau-ltd\\\/\",\"https:\\\/\\\/www.instagram.com\\\/pabausoftware\\\/\"],\"description\":\"Pabau is an all-in-one healthcare practice management software platform designed for clinics, medspas, therapists, and medical professionals. It combines scheduling, electronic health records, clinical forms, payments, marketing automation, reporting, and patient engagement tools into one secure cloud system to help practices streamline operations and grow their business.\",\"foundingDate\":\"2011-10-20\",\"numberOfEmployees\":{\"@type\":\"QuantitativeValue\",\"minValue\":\"201\",\"maxValue\":\"500\"}},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/#\\\/schema\\\/person\\\/73b672a49e20bfba8161e3c17ee3dda2\",\"name\":\"Aleksandar Kochovski\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"nl-NL\",\"@id\":\"https:\\\/\\\/pabau.com\\\/wp-content\\\/uploads\\\/2026\\\/06\\\/cropped-aleksandar-kochovski-profile-picture-96x96.jpeg\",\"url\":\"https:\\\/\\\/pabau.com\\\/wp-content\\\/uploads\\\/2026\\\/06\\\/cropped-aleksandar-kochovski-profile-picture-96x96.jpeg\",\"contentUrl\":\"https:\\\/\\\/pabau.com\\\/wp-content\\\/uploads\\\/2026\\\/06\\\/cropped-aleksandar-kochovski-profile-picture-96x96.jpeg\",\"caption\":\"Aleksandar Kochovski\"},\"description\":\"Aleksandar is a content strategist and editor working in tech publishing, with a background in higher education. He specializes in topics around compliance in software solutions. When he's not writing at Pabau, you can find him tending to his bonsai collection or hitting the gym.\",\"url\":\"https:\\\/\\\/pabau.com\\\/nl\\\/blog\\\/author\\\/aleksandar-kochovski\\\/\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250169\",\"position\":1,\"url\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250169\",\"name\":\"What is ICD-10 Code M45.6?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"ICD-10 Code M45.6 is the billable ICD-10-CM diagnosis code for ankylosing spondylitis of the lumbar region. It is valid for FY2026 claims, became effective October 1, 2025, and falls under Chapter 13 of ICD-10-CM (diseases of the musculoskeletal system, M00-M99).\",\"inLanguage\":\"nl-NL\"},\"inLanguage\":\"nl-NL\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250170\",\"position\":2,\"url\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250170\",\"name\":\"Is M45.6 a billable ICD-10-CM code?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. M45.6 is a billable and specific ICD-10-CM code valid for use in FY2026 diagnosis and reimbursement submissions. It requires physician documentation of confirmed ankylosing spondylitis with the lumbar region identified as the affected site.\",\"inLanguage\":\"nl-NL\"},\"inLanguage\":\"nl-NL\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250171\",\"position\":3,\"url\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250171\",\"name\":\"What is the difference between M45.6 and M45.9?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"M45.6 specifies ankylosing spondylitis of the lumbar region. M45.9 is used only when no spinal site has been documented. When the lumbar region is recorded in the clinical note, M45.6 is the correct code. Using M45.9 for a documented lumbar case is a common specificity error that invites payer scrutiny.\",\"inLanguage\":\"nl-NL\"},\"inLanguage\":\"nl-NL\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250172\",\"position\":4,\"url\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250172\",\"name\":\"What documentation is required to use ICD-10 Code M45.6?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"The physician must explicitly document a confirmed ankylosing spondylitis diagnosis and identify the lumbar spine as the affected region. Supporting evidence such as imaging findings, HLA-B27 status, or inflammatory markers strengthens the clinical record but does not replace the diagnostic statement.\",\"inLanguage\":\"nl-NL\"},\"inLanguage\":\"nl-NL\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250173\",\"position\":5,\"url\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250173\",\"name\":\"Is axial spondyloarthritis coded the same as ankylosing spondylitis?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No. Ankylosing spondylitis with radiographic confirmation maps to M45 codes, including M45.6. Non-radiographic axial spondyloarthritis has its own subcodes inside M45, the M45.A series, with M45.A6 covering the lumbar region. Verify the physician's documented imaging evidence before selecting M45.6.\",\"inLanguage\":\"nl-NL\"},\"inLanguage\":\"nl-NL\"},{\"@type\":\"Question\",\"@id\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250174\",\"position\":6,\"url\":\"https:\\\/\\\/pabau.com\\\/nl\\\/diagnostic-codes\\\/icd-10-code-m456\\\/#faq-question-1785753250174\",\"name\":\"What was the ICD-9 equivalent of M45.6?\",\"answerCount\":1,\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"The closest ICD-9-CM equivalent is 720.0 (Ankylosing spondylitis). ICD-9-CM did not distinguish between spinal regions, so a single code mapped to all AS diagnoses. Under ICD-10-CM, 720.0 converts to multiple M45 subcodes depending on the documented spinal site. Converting legacy claims requires reviewing the original clinical note rather than defaulting to M45.9.\",\"inLanguage\":\"nl-NL\"},\"inLanguage\":\"nl-NL\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"ICD-10 Code M45.6: Lumbar ankylosing spondylitis billing 2026","description":"M45.6 is the billable ICD-10-CM code for ankylosing spondylitis of the lumbar region. Non-radiographic axSpA belongs in M45.A, not M46.x.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/","og_locale":"nl_NL","og_type":"article","og_title":"ICD-10 Code M45.6: Lumbar ankylosing spondylitis billing 2026","og_description":"M45.6 is the billable ICD-10-CM code for ankylosing spondylitis of the lumbar region. Non-radiographic axSpA belongs in M45.A, not M46.x.","og_url":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/","og_site_name":"Pabau","article_publisher":"https:\/\/www.facebook.com\/Pabau\/","article_published_time":"2026-08-03T13:56:05+00:00","article_modified_time":"2026-08-17T12:29:43+00:00","og_image":[{"width":1200,"height":630,"url":"https:\/\/pabau.com\/wp-content\/uploads\/2026\/08\/icd-10-code-m456.webp","type":"image\/webp"}],"author":"Aleksandar Kochovski","twitter_card":"summary_large_image","twitter_creator":"@pabaucrm","twitter_site":"@pabaucrm","twitter_misc":{"Geschreven door":"Aleksandar Kochovski","Geschatte leestijd":"12 minuten"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#article","isPartOf":{"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/"},"author":{"name":"Aleksandar Kochovski","@id":"https:\/\/pabau.com\/nl\/#\/schema\/person\/73b672a49e20bfba8161e3c17ee3dda2"},"headline":"ICD-10 Code M45.6: Ankylosing spondylitis lumbar region","datePublished":"2026-08-03T13:56:05+00:00","dateModified":"2026-08-17T12:29:43+00:00","mainEntityOfPage":{"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/"},"wordCount":2321,"publisher":{"@id":"https:\/\/pabau.com\/nl\/#organization"},"image":{"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#primaryimage"},"thumbnailUrl":"https:\/\/pabau.com\/wp-content\/uploads\/2026\/08\/icd-10-code-m456.webp","keywords":["Billing Guide","ICD-10","ICD-10 codes","Rheumatology coding","Spine Coding"],"articleSection":["Billing Codes","Diagnostic Codes","ICD-10-CM","Musculoskeletal &amp; Pain Management"],"inLanguage":"nl-NL"},{"@type":["WebPage","FAQPage"],"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/","url":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/","name":"ICD-10 Code M45.6: Lumbar ankylosing spondylitis billing 2026","isPartOf":{"@id":"https:\/\/pabau.com\/nl\/#website"},"primaryImageOfPage":{"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#primaryimage"},"image":{"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#primaryimage"},"thumbnailUrl":"https:\/\/pabau.com\/wp-content\/uploads\/2026\/08\/icd-10-code-m456.webp","datePublished":"2026-08-03T13:56:05+00:00","dateModified":"2026-08-17T12:29:43+00:00","description":"M45.6 is the billable ICD-10-CM code for ankylosing spondylitis of the lumbar region. Non-radiographic axSpA belongs in M45.A, not M46.x.","mainEntity":[{"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250169"},{"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250170"},{"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250171"},{"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250172"},{"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250173"},{"@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250174"}],"inLanguage":"nl-NL","potentialAction":[{"@type":"ReadAction","target":["https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/"]}]},{"@type":"ImageObject","inLanguage":"nl-NL","@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#primaryimage","url":"https:\/\/pabau.com\/wp-content\/uploads\/2026\/08\/icd-10-code-m456.webp","contentUrl":"https:\/\/pabau.com\/wp-content\/uploads\/2026\/08\/icd-10-code-m456.webp","width":1200,"height":630},{"@type":"WebSite","@id":"https:\/\/pabau.com\/nl\/#website","url":"https:\/\/pabau.com\/nl\/","name":"Pabau","description":"Clinic Software for your Business | Go Paperless Today","publisher":{"@id":"https:\/\/pabau.com\/nl\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/pabau.com\/nl\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"nl-NL"},{"@type":"Organization","@id":"https:\/\/pabau.com\/nl\/#organization","name":"Pabau","url":"https:\/\/pabau.com\/nl\/","logo":{"@type":"ImageObject","inLanguage":"nl-NL","@id":"https:\/\/pabau.com\/nl\/#\/schema\/logo\/image\/","url":"https:\/\/pabau.com\/wp-content\/uploads\/2022\/05\/Logo-4-e1654525062364.png","contentUrl":"https:\/\/pabau.com\/wp-content\/uploads\/2022\/05\/Logo-4-e1654525062364.png","width":736,"height":195,"caption":"Pabau"},"image":{"@id":"https:\/\/pabau.com\/nl\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/Pabau\/","https:\/\/x.com\/pabaucrm","https:\/\/www.linkedin.com\/company\/pabau-ltd\/","https:\/\/www.instagram.com\/pabausoftware\/"],"description":"Pabau is an all-in-one healthcare practice management software platform designed for clinics, medspas, therapists, and medical professionals. It combines scheduling, electronic health records, clinical forms, payments, marketing automation, reporting, and patient engagement tools into one secure cloud system to help practices streamline operations and grow their business.","foundingDate":"2011-10-20","numberOfEmployees":{"@type":"QuantitativeValue","minValue":"201","maxValue":"500"}},{"@type":"Person","@id":"https:\/\/pabau.com\/nl\/#\/schema\/person\/73b672a49e20bfba8161e3c17ee3dda2","name":"Aleksandar Kochovski","image":{"@type":"ImageObject","inLanguage":"nl-NL","@id":"https:\/\/pabau.com\/wp-content\/uploads\/2026\/06\/cropped-aleksandar-kochovski-profile-picture-96x96.jpeg","url":"https:\/\/pabau.com\/wp-content\/uploads\/2026\/06\/cropped-aleksandar-kochovski-profile-picture-96x96.jpeg","contentUrl":"https:\/\/pabau.com\/wp-content\/uploads\/2026\/06\/cropped-aleksandar-kochovski-profile-picture-96x96.jpeg","caption":"Aleksandar Kochovski"},"description":"Aleksandar is a content strategist and editor working in tech publishing, with a background in higher education. He specializes in topics around compliance in software solutions. When he's not writing at Pabau, you can find him tending to his bonsai collection or hitting the gym.","url":"https:\/\/pabau.com\/nl\/blog\/author\/aleksandar-kochovski\/"},{"@type":"Question","@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250169","position":1,"url":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250169","name":"What is ICD-10 Code M45.6?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"ICD-10 Code M45.6 is the billable ICD-10-CM diagnosis code for ankylosing spondylitis of the lumbar region. It is valid for FY2026 claims, became effective October 1, 2025, and falls under Chapter 13 of ICD-10-CM (diseases of the musculoskeletal system, M00-M99).","inLanguage":"nl-NL"},"inLanguage":"nl-NL"},{"@type":"Question","@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250170","position":2,"url":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250170","name":"Is M45.6 a billable ICD-10-CM code?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"Yes. M45.6 is a billable and specific ICD-10-CM code valid for use in FY2026 diagnosis and reimbursement submissions. It requires physician documentation of confirmed ankylosing spondylitis with the lumbar region identified as the affected site.","inLanguage":"nl-NL"},"inLanguage":"nl-NL"},{"@type":"Question","@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250171","position":3,"url":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250171","name":"What is the difference between M45.6 and M45.9?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"M45.6 specifies ankylosing spondylitis of the lumbar region. M45.9 is used only when no spinal site has been documented. When the lumbar region is recorded in the clinical note, M45.6 is the correct code. Using M45.9 for a documented lumbar case is a common specificity error that invites payer scrutiny.","inLanguage":"nl-NL"},"inLanguage":"nl-NL"},{"@type":"Question","@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250172","position":4,"url":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250172","name":"What documentation is required to use ICD-10 Code M45.6?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"The physician must explicitly document a confirmed ankylosing spondylitis diagnosis and identify the lumbar spine as the affected region. Supporting evidence such as imaging findings, HLA-B27 status, or inflammatory markers strengthens the clinical record but does not replace the diagnostic statement.","inLanguage":"nl-NL"},"inLanguage":"nl-NL"},{"@type":"Question","@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250173","position":5,"url":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250173","name":"Is axial spondyloarthritis coded the same as ankylosing spondylitis?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"No. Ankylosing spondylitis with radiographic confirmation maps to M45 codes, including M45.6. Non-radiographic axial spondyloarthritis has its own subcodes inside M45, the M45.A series, with M45.A6 covering the lumbar region. Verify the physician's documented imaging evidence before selecting M45.6.","inLanguage":"nl-NL"},"inLanguage":"nl-NL"},{"@type":"Question","@id":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250174","position":6,"url":"https:\/\/pabau.com\/nl\/diagnostic-codes\/icd-10-code-m456\/#faq-question-1785753250174","name":"What was the ICD-9 equivalent of M45.6?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"The closest ICD-9-CM equivalent is 720.0 (Ankylosing spondylitis). ICD-9-CM did not distinguish between spinal regions, so a single code mapped to all AS diagnoses. Under ICD-10-CM, 720.0 converts to multiple M45 subcodes depending on the documented spinal site. Converting legacy claims requires reviewing the original clinical note rather than defaulting to M45.9.","inLanguage":"nl-NL"},"inLanguage":"nl-NL"}]}},"yoast":{"focus_keyword":"ICD-10 Code M45.6","seo_title":"ICD-10 Code M45.6: Lumbar ankylosing spondylitis billing 2026","meta_description":"M45.6 is the billable ICD-10-CM code for ankylosing spondylitis of the lumbar region. Non-radiographic axSpA belongs in M45.A, not M46.x.","content_score":"","is_cornerstone":"","related_keyphrases":[{"keyword":"ankylosing spondylitis diagnosis code","synonyms":["icd-10 m45.6","m45.6 ankylosing spondylitis lumbar region","ankylosing spondylitis icd 10"]},{"keyword":"m45.6 icd-10-cm","synonyms":["icd-10 m45.6","m45.6 ankylosing spondylitis lumbar region","ankylosing spondylitis icd 10"]},{"keyword":"ankylosing spondylitis lumbar region","synonyms":["icd-10 m45.6","m45.6 ankylosing spondylitis lumbar region","ankylosing spondylitis icd 10"]}]},"_links":{"self":[{"href":"https:\/\/pabau.com\/nl\/wp-json\/wp\/v2\/posts\/171318","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pabau.com\/nl\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pabau.com\/nl\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pabau.com\/nl\/wp-json\/wp\/v2\/users\/81"}],"replies":[{"embeddable":true,"href":"https:\/\/pabau.com\/nl\/wp-json\/wp\/v2\/comments?post=171318"}],"version-history":[{"count":3,"href":"https:\/\/pabau.com\/nl\/wp-json\/wp\/v2\/posts\/171318\/revisions"}],"predecessor-version":[{"id":183135,"href":"https:\/\/pabau.com\/nl\/wp-json\/wp\/v2\/posts\/171318\/revisions\/183135"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pabau.com\/nl\/wp-json\/wp\/v2\/media\/171317"}],"wp:attachment":[{"href":"https:\/\/pabau.com\/nl\/wp-json\/wp\/v2\/media?parent=171318"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pabau.com\/nl\/wp-json\/wp\/v2\/categories?post=171318"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pabau.com\/nl\/wp-json\/wp\/v2\/tags?post=171318"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}