Open repair of tibial nonunion or malunion using iliac crest or other autograft, including harvest of the graft at the same operative session.

Verified May 8, 2026 · 6 sources ↓

Medicare: $1,134.63
Total RVUs: 33.97
Global, days: 90
Region: Foot & ankle

Drawn from AAPCCMSGenhealthAAOSMdclarity

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Confirm diagnosis as tibial nonunion or malunion with imaging (X-ray or CT) showing failed union or malalignment
Specify the graft donor site (e.g., ipsilateral iliac crest, contralateral iliac crest, or alternative autograft source)
Document graft harvest technique and approximate volume or dimensions of bone harvested
Describe placement of graft at the nonunion/malunion site and method of fixation (plate, nail, screws, external fixator)
Record intraoperative fluoroscopy or imaging confirming alignment after repair
Note any prior failed treatment attempts (prior ORIF hardware, previous bone grafting) to support medical necessity

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 24 Unrelated E/M during global 51 Multiple procedures 52 Reduced services 58 Staged or related 59 Distinct service 62 Co-surgeons 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 27724 covers open surgical correction of a tibia that has failed to unite (nonunion) or has healed in an unacceptable position (malunion) after fracture, performed with autogenous bone graft harvested from the iliac crest or another donor site during the same procedure. The graft is placed between or around the fracture fragments to stimulate osseous healing and restore mechanical alignment. Graft harvest is bundled — do not separately report a graft-harvest code.

This is a 90-day global procedure. All routine post-op visits, wound checks, and cast or splint changes through day 90 are included. Any visit or procedure unrelated to tibial repair within the global window requires modifier 24 (E/M) or 79 (unrelated procedure). A return to the OR for a complication directly related to the tibial repair — hardware failure, wound dehiscence, re-fixation — uses modifier 78.

Distinguish 27724 from 27722 (nonunion/malunion repair without graft) and 27725 (synostosis with fibula). If the operative note doesn't confirm autograft harvest, payers will downcode to 27722. Document the donor site, volume of graft harvested, and placement technique explicitly.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	18.83
Practice expense RVU	11.18
Malpractice RVU	3.96
Total RVU	33.97
Medicare national rate	$1,134.63
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	$1,134.63
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI J8) Ambulatory surgical center (freestanding)	$4,974.17

Common denial reasons

The recurring reasons claims for CPT 27724 get rejected.

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

Downcoding to 27722 when operative note lacks explicit documentation of autograft harvest
Medical necessity denial when pre-op imaging is absent or does not confirm nonunion/malunion diagnosis
Separate graft-harvest CPT code billed in addition to 27724, triggering NCCI bundling edit
Global period conflict when post-op E/M visits are billed without modifier 24 during the 90-day window
Incorrect laterality — failing to append LT or RT when payer edits require anatomic modifier for unilateral leg procedures

Frequently asked questions

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

01What is the difference between CPT 27724 and 27722?

27722 covers nonunion or malunion repair without bone graft. 27724 requires autograft harvest and placement. If the operative note doesn't document graft harvest, payers will downcode to 27722 — a meaningful reimbursement difference.

02Can I bill separately for iliac crest bone graft harvest?

No. The code descriptor explicitly includes obtaining the graft. Billing a separate harvest code triggers an NCCI bundling edit and will be denied.

03What modifiers apply if I perform 27724 on both tibiae at the same session?

Bilateral tibial repair at a single session is rare but possible. Append LT and RT to separate line items and modifier 51 on the secondary procedure. Expect payer scrutiny — document medical necessity for bilateral intervention thoroughly.

04How does the 90-day global period affect post-op billing?

All routine follow-up through day 90 is bundled. Append modifier 24 on E/M visits for unrelated conditions within that window. Use modifier 78 for an unplanned return to the OR for a complication related to the tibial repair, and modifier 79 for an unrelated surgical problem.

05When is modifier 22 appropriate for 27724?

Modifier 22 applies when the procedure is substantially more complex than typical — for example, revision after prior failed grafting with extensive scar, hardware removal required before new fixation, or unusually difficult anatomy. Document increased operative time and the specific factors driving complexity in the operative note.

06What ICD-10 diagnoses support 27724?

Tibial nonunion (M84.361–M84.369 for delayed union; M84.361A–S for sequelae) and malunion (M84.371–M84.379) are the primary diagnoses. The laterality and encounter type (initial, subsequent, sequela) must match across the claim.

07Is 27724 performed in an ASC or only hospital outpatient?

27724 is payable in both HOPD and ASC settings under CMS 2026. Payment rates differ between the two sites — see the Site of Service comparison on this page. Confirm your ASC is approved for orthopedic reconstruction cases before scheduling.

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 nonunion or malunion diagnosis, donor site identification, graft harvest description, placement technique, and fixation method directly from surgeon dictation. That detail prevents the single most common denial for 27724: downcoding to 27722 because the operative note didn't explicitly confirm autograft harvest was performed.

See how Mira captures CPT 27724 documentation