Osteotomy of multiple metatarsals performed during a single operative session, typically to correct forefoot deformity, transfer metatarsalgia, or address pathologic alignment across more than one ray.

Verified May 8, 2026 · 6 sources ↓

Medicare: $835.69
Total RVUs: 25.02
Global, days: 90
Region: Foot & ankle

Drawn from CMSAAPCCgsmedicareEmedny

Documentation requirements

What must appear in the operative or office note to support the claim.

Source · Editorial brief grounded in 6 cited references ↓

Identify each specific metatarsal on which osteotomy was performed (e.g., 2nd, 3rd, 4th ray) — vague references to 'multiple metatarsals' without enumeration flag audits
State the type of osteotomy performed at each ray (Weil, dorsal closing wedge, oblique, etc.) — 'standard approach' language is an audit risk
Document the preoperative diagnosis and clinical indication for each metatarsal addressed, including failure or inadequacy of conservative treatment
Include intraoperative fluoroscopy findings if imaging guidance was used to verify osteotomy position, and note whether it is separately billable or integral to the procedure
Record fixation method for each osteotomy site (K-wire, screw, no internal fixation) to support implant billing where applicable
Note any concurrent procedures performed through separate incisions or on separate anatomical structures to support additional CPT codes with appropriate modifiers

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 50 Bilateral procedure 51 Multiple procedures 58 Staged or related 59 Distinct service 76 Repeat, same physician 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 28309 covers surgical cutting of multiple metatarsal bones in one operative setting. It is the appropriate code when the operative note documents osteotomy performed on more than one metatarsal — as opposed to 28308, which applies to a single metatarsal osteotomy. Common clinical scenarios include Weil osteotomies across multiple rays for metatarsalgia, corrective forefoot reconstruction following Charcot arthropathy, or realignment procedures for rheumatoid forefoot deformity.

The 90-day global period means all routine post-op visits, wound checks, dressing changes, and cast management through day 90 are bundled. Unrelated E/M services or procedures during that window require modifier 24 or 79, respectively. If a staged procedure on a different site is planned and performed within the global, use modifier 58. Bilateral forefoot osteotomies billed on the same day require modifier 50 on a single claim line for most Part B carriers; ASC settings require separate LT and RT lines.

ICD-10 diagnosis coding must support medical necessity — metatarsalgia (M77.4x), acquired deformity of toes (M20.5x), rheumatoid arthritis with foot involvement (M05.37x), and Charcot arthropathy (M14.67x) are common pairings. Payers, particularly commercial plans, may require documented failure of conservative management before authorizing this procedure.

RVU & reimbursement

Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	13.81
Practice expense RVU	8.96
Malpractice RVU	2.25
Total RVU	25.02
Medicare national rate	$835.69
Global period	90 days

Payment by site of service

Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.

Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026

Setting	Medicare rate (national)
Office (PFS non-facility) Procedure performed in physician's office	$835.69
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI A2) Ambulatory surgical center (freestanding)	$3,695.53

Common denial reasons

The recurring reasons claims for CPT 28309 get rejected.

Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓

Upcoding scrutiny: billing 28309 when the operative note documents only one metatarsal osteotomy — that maps to 28308, not 28309
Missing or vague ICD-10 linkage — payers deny when the diagnosis code does not directly correspond to the metatarsal(s) documented as surgically treated
Lack of documented conservative treatment failure prior to surgical authorization, particularly for commercial and Medicare Advantage plans
Bundling conflicts when same-day lesser toe procedures (e.g., 28285, 28308) are billed without NCCI-compliant modifier or without documentation of distinct anatomical sites
Bilateral procedure billing errors — submitting two units of 28309 instead of modifier 50 (Part B) or separate LT/RT lines (ASC) triggers claim-level rejection

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01What is the difference between 28308 and 28309?

28308 is for a single metatarsal osteotomy. 28309 applies when osteotomy is performed on more than one metatarsal in the same session. If your operative note documents two Weil osteotomies on separate rays, 28309 is the correct single code — not two units of 28308.

02Can I bill 28309 with lesser toe correction codes on the same day?

Potentially yes, but check NCCI PTP edits first. When lesser toe procedures (e.g., 28285) are performed through a separate incision at a distinct anatomical site, modifier 59 or XS can bypass the bundling edit if documentation supports it. Use the CGS NCCI PTP lookup tool to confirm current edit status before billing.

03How is bilateral 28309 billed correctly?

For Medicare Part B, bill one line with modifier 50. For ASC claims, bill two lines — one with LT and one with RT, each with one unit of service. Do not bill two units of 28309 on a single line without modifier 50; that triggers a MUE denial.

04What is the global period for 28309 and what does it include?

The global period is 90 days. It covers the operative day, the day-before pre-op visit if billed, and all routine post-op care through day 90 including office visits, wound checks, and cast/splint management. Separate billing in that window for unrelated services requires modifier 24 (E/M) or 79 (unrelated procedure).

05Does intraoperative fluoroscopy bill separately with 28309?

Only if it is not already integral to the osteotomy technique. Per NCCI policy, if the code descriptor or CMS guidance indicates imaging is included, you cannot bill fluoroscopy separately. Review the operative report and applicable NCCI guidance before appending an imaging code.

06Which ICD-10 codes most commonly support 28309?

Metatarsalgia (M77.4x), acquired deformities of toes (M20.5x), rheumatoid arthritis with foot involvement (M05.37x), and Charcot arthropathy (M14.67x) are the most frequently paired diagnoses. The diagnosis must map specifically to the metatarsals treated — a general foot pain code will not reliably clear prior authorization or post-payment review.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira AI Scribe

Mira's AI scribe captures the number of metatarsals treated, osteotomy type at each ray, fixation method, and approach from dictation — locking in the specificity that separates a defensible 28309 from a downcoded 28308 or an unsupported claim. That prevents the most common denial pattern for this code: operative notes that reference multiple metatarsals in passing without naming each bone and technique.

See how Mira captures CPT 28309 documentation