CPT code 28485 – Open treatment of metatarsal fracture

Key takeaways

CPT code 28485 covers open treatment of a fracture of any metatarsal, 1st through 5th, and is reported once per fractured metatarsal.

Great-toe phalanx fractures use their own codes: 28490, 28495 or 28496 for closed or percutaneous treatment, and 28505 for open treatment.

A 90-day global period applies, so routine post-op E&M visits are bundled and cannot be billed separately during that window.

Most payers want modifier LT or RT. A second or later metatarsal treated open in the same session also needs modifier 59 or XS.

Pabau’s claims management software checks claims for missing or invalid details, verifies eligibility through Claim.MD, and attaches prior authorizations at booking.

CPT code 28485: Official descriptor and procedure overview

CPT code 28485 is defined by the American Medical Association’s CPT code set as: Open treatment of metatarsal fracture, includes internal fixation, when performed, each. “When performed” means the code applies whether or not fixation hardware was placed, as long as the approach was open. “Each” means it is reported once per fractured metatarsal.

“Open treatment” means a skin incision was made to directly visualize and reduce the fracture. That separates it from closed manipulation performed through intact skin. Internal fixation refers to hardware placed during surgery: plates and screws, Kirschner wires (K-wires), or an intramedullary nail. The code covers any metatarsal, from the 1st to the 5th.

• Anatomical scope: Any metatarsal, 1st through 5th, reported once per fractured metatarsal. Great-toe phalanx fractures are coded separately with 28490, 28495, 28496 or 28505.
• Surgical elements bundled into 28485: Skin incision, fracture exposure, reduction, hardware placement, fluoroscopic guidance (when used), and wound closure.
• Fixation is optional: Some open reductions are stabilized with cast immobilization alone rather than hardware; 28485 applies either way once the open approach is confirmed.
• Facility vs. non-facility: The procedure is typically performed in a hospital outpatient department (HOPD) or ambulatory surgery center (ASC). That setting affects the practice expense component of reimbursement.

What CPT code 28485 includes and what it excludes

Knowing which components of CPT code 28485 are bundled and which are separately reportable prevents both under-coding and NCCI bundling violations. The global surgical package already wraps a defined set of services into the base payment.

Bone graft harvested through a separate incision is easy to miss as a separately billable service. If the operative note documents it, report CPT 20900 or 20902 in addition to 28485. NCCI edit pairs change during the year, so check them each quarter and confirm payment indicators in the CMS Physician Fee Schedule lookup tool.

How CPT code 28485 differs from adjacent metatarsal fracture codes

The metatarsal fracture codes run from 28470 to 28485, and the great-toe codes 28490 to 28505 sit right next to them. Picking the wrong one is a costly documentation error in foot fracture billing. The deciding variables are approach (open or closed), whether manipulation was performed, and the anatomical site.

Confusing closed and open treatment is a commonly flagged audit error in foot fracture billing. The decision path below follows the operative note one question at a time.

For 28485 to be supportable, the operative note must describe a skin incision. If the surgeon performed closed manipulation only and the note mentions no incision, code 28475 or 28476. That holds whatever fixation was used.

Operative documentation requirements for CPT code 28485

Payers reviewing CPT code 28485 claims expect the operative note to confirm several elements before paying at the open-treatment rate. Missing one of them can lead to a CO-50 denial (not medically necessary as documented). Good medical billing compliance starts with knowing what the auditor’s checklist contains.

• Open approach confirmed: The note must explicitly state that a skin incision was made and describe its location relative to the affected metatarsal. Phrases like “surgical approach,” “incision made over the dorsal aspect of the 3rd metatarsal,” or “fracture site exposed” establish this.
• Fracture identification: The operative note should identify which metatarsal was treated, whether the fracture was displaced or non-displaced, and its pattern (transverse, oblique, comminuted).
• Fixation hardware documented: If fixation was performed, the note must name the hardware type (plate, screws, K-wire, IMN) and the number and size of implants. It should also confirm that reduction was verified under fluoroscopy.
• Fluoroscopy documentation: If intraoperative imaging was used, document it, including the number of images. Fluoroscopy is bundled into 28485 and not separately billable, but auditors look for its mention.
• Surgeon credentials: The operating surgeon must be credentialed and enrolled with the payer for surgical fracture repair. Podiatrists (DPM) are authorized for this code under most plans, but MAC-specific LCD policies for Medicare should be verified.

Submitting a clean claim for CPT code 28485 requires all documentation to be in the system before the claim leaves the practice. A clear operative note template for metatarsal ORIF procedures standardizes documentation across surgeons and reduces retrospective audit exposure.

ICD-10 codes paired with CPT code 28485

Metatarsal fracture ICD-10-CM codes fall under category S92.3, which covers metatarsals 1 to 5. S92.31- codes the 1st metatarsal, S92.32- through S92.35- the 2nd through 5th, and S92.30- an unspecified metatarsal. Three variables must match the operative note exactly: laterality, displacement status, and encounter type.

The 7th character “A” applies to the initial surgical encounter and to any visit that is active treatment. Use “B” instead when the fracture itself was open, meaning the injury broke the skin. Open treatment does not turn a closed fracture into an open one.

Follow-up visits use “D” for routine healing, “G” for delayed healing, “K” for nonunion, and “P” for malunion. A routine post-op visit for a displaced right 2nd metatarsal fracture, for example, is coded S92.321D. The CDC/NCHS ICD-10-CM system updates the codes every October 1. Check laterality and displacement codes against the current fiscal year’s tables before submission.

Modifiers that apply to 28485 claims

Wrong or missing modifiers are a primary denial trigger on CPT code 28485 claims. Each modifier serves a specific function and needs its own documentation support.

• LT / RT (laterality): Required by most payers to indicate left or right foot. Append RT for the right foot, LT for the left. Some Medicare Administrative Contractors (MACs) require laterality modifiers on all foot surgery claims. Check your MAC’s local coverage determination (LCD) before submitting without one.
• 59 (distinct procedural service): Required when billing CPT code 28485 more than once in the same operative session (multiple metatarsals). Append modifier 59 to the second and each subsequent unit to bypass NCCI bundling edits. Verify NCCI edits quarterly via the CMS NCCI tool.
• XS (separate structure): The CMS-preferred alternative to modifier 59 for Medicare claims where the second metatarsal treated is anatomically distinct from the first. XS (and XE, XP, XU) are more specific than 59 and reduce audit risk on Medicare claims.
• 51 (multiple procedures): Signals that more than one procedure was performed in the same session. The second procedure is reimbursed at 50% of its allowed amount. Do not use with add-on codes.
• 22 (increased procedural services): Used when the procedure took substantially more work than typically described, such as a severely comminuted fracture with extensive soft-tissue dissection. It needs a written explanation in the operative note and a cover letter to the payer detailing the added complexity.

Billing multiple metatarsal fractures in a single operative session

When two or more metatarsal fractures need open treatment in the same session, CPT code 28485 is reported once per metatarsal treated. That follows from the word “each” in the descriptor. Getting it wrong triggers both underpayment and NCCI violations.

Correct billing sequence for two metatarsals (same session, same foot):

1. Report CPT 28485 on the first line with modifier RT (or LT) only.
2. Report CPT 28485 a second time on a new line with modifier RT (or LT) plus modifier 59 (or XS for Medicare).
3. The second unit is reimbursed at 50% of the allowed amount under the multiple-procedure reduction rule.
4. If bone graft was harvested through a separate incision, add CPT 20900 or 20902 on its own line with modifier 59. That separates it from the fracture codes.

Three metatarsals treated open in the same session follow the same pattern. The third unit of 28485 again carries modifier 59, and its payment also drops to 50%. The 100%/50%/50% structure is the Medicare multiple surgery rule in the Medicare Claims Processing Manual, Chapter 12, section 40.6.

Global surgery period and post-operative billing

The global surgery period for CPT code 28485 is 90 days, beginning the day after the operative date. During that window, routine post-operative evaluation and management (E&M) services are bundled into the procedure payment and cannot be billed separately.

• Bundled (not separately billable): Post-op wound checks, suture removal, cast changes, and any E&M visit whose chief complaint relates directly to the fracture repair. Follow-up X-rays are diagnostic tests and are billed separately.
• Separately billable with modifier 24: An E&M visit for a condition unrelated to the metatarsal fracture, such as hypertension management during the global period.
• Separately billable with modifier 78: A return to the operating room during the global period for a complication of the original procedure. Hardware failure needing revision is a typical case.
• Separately billable with modifier 79: An unrelated surgical procedure performed during the global period (a different anatomical site or diagnosis).

Billing routine post-op visits without a modifier during the 90-day global period is commonly flagged in surgical audits. Start a global period tracker for every CPT code 28485 claim on the day of surgery, not retrospectively.

Medicare reimbursement and RVUs for CPT code 28485

Medicare reimbursement for CPT code 28485 is calculated from relative value units (RVUs) set annually in the Medicare Physician Fee Schedule (MPFS). Rates vary by geographic practice cost index (GPCI), so the figures below are approximate national values from the FastRVU 2026 RVU lookup tool. Verify them on the CMS PFS search tool for your locality before you rely on them.

These figures reflect CMS payment to the physician or surgeon only and exclude facility fees paid to the ASC or hospital. Commercial payers typically reimburse at a multiple of the Medicare rate, commonly 110% to 200% depending on the payer contract.

Prior authorization requirements for CPT code 28485

Prior authorization (PA) requirements for CPT code 28485 depend on payer type. Traditional Medicare (fee-for-service) does not require PA for surgical fracture repair in most cases. Medicare Advantage plans are a different matter. CMS lets MA plans require prior authorization for services that traditional Medicare covers without it, and many do for orthopedic surgery.

Thorough insurance eligibility verification before surgery should include a check on whether the patient’s specific plan requires PA for surgical codes in the 28xxx range. The documentation typically requested includes:

• Imaging confirming the fracture (X-ray, CT scan, or MRI report)
• Clinical notes documenting the mechanism of injury and symptom severity
• Confirmation that conservative management was attempted or is contraindicated (displacement severity, instability, or patient activity requirements)
• Surgeon’s clinical justification for open versus closed treatment

For Medicaid, PA requirements vary significantly by state managed care organization. Commercial insurers often require PA for surgical procedures above a defined complexity threshold. Missing or expired prior authorization is a commonly flagged denial reason for 28485 claims, especially where no one tracks authorizations systematically.

Common denial reasons and how to avoid them

Systematic denial management workflows for CPT code 28485 start with the CARC (Claim Adjustment Reason Code) that comes with each rejection. Each denial type has a distinct corrective action.

CO-97 is a frequent denial on CPT code 28485 claims. It means “the benefit for this service is included in the payment/allowance for another service or procedure that has already been adjudicated.” The usual cause is a post-op visit billed during the global period. Another cause is a separately reportable code, such as a bone graft harvest, sent without the modifier that unbundles it.

For codes outside this table, our CARC reference for billers maps each adjustment reason to the corrective action.

How practice management software supports CPT code 28485 billing

Podiatric and orthopedic practices billing CPT code 28485 tend to lose money at three points. Claims go out with missing details, eligibility is checked too late, and prior authorization isn’t tracked when the surgery is booked. Purpose-built claims management software catches these before submission rather than after a denial.

Pabau, the practice management platform we build, scrubs every claim for missing or invalid details before it leaves the system. US claims go out as CMS-1500s through Claim.MD to thousands of payers. Insurance eligibility verification runs through Claim.MD before the visit, so coverage problems surface ahead of the surgery date.

Each prior authorization is stored in Pabau as a case. Attach the case when booking the surgery, and the authorization code follows the appointment through to the claim. If a claim still comes back rejected, Pabau flags it as Needs action so your billing team can correct it.

Catch CPT 28485 claim errors before submission

Pabau checks each claim for missing or invalid details, verifies eligibility through Claim.MD, and attaches prior authorizations at booking. Your billing team spends less time reworking denied foot surgery claims.

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Conclusion

The incision decides a 28485 claim. If the operative note shows one over a named metatarsal, report 28485 once per bone with laterality and distinct-procedure modifiers. If it doesn’t, code closed or percutaneous treatment, however much hardware went in.

The cheapest fixes sit upstream of the claim. A standard operative note template and an authorization check at booking head off most of the denial scenarios in this guide. Start the 90-day clock on the surgery date, and follow-up visits stop leaking into rejected claims.

Want claim validation, eligibility checks and authorization cases in one billing workflow for your foot surgery claims? Book a demo to see how Pabau handles it.

Continue your research

Need to understand how clearinghouse validation works? Medical claims clearinghouse guide explains how claims are scrubbed, transmitted, and adjudicated before reaching the payer.

Working through a denied surgical claim? Denial codes in medical billing maps CARC and RARC codes to corrective actions for common surgical procedure denials.

Want a step-by-step on submitting 837P claims electronically? 837 file guide covers the electronic transaction standard for professional claims, including loop and segment requirements.

Planning authorization before the surgery date? Prior authorization process walks through each step from request to approval.

Billing a larger graft alongside the fracture repair? CPT code 20902 covers major or large bone graft harvest and how it differs from 20900.

Frequently asked questions