Open ankle joint arthrotomy with removal of the synovial membrane lining, performed through direct incision of the ankle joint capsule.

Verified May 8, 2026 · 8 sources ↓

Medicare: $548.11
Total RVUs: 16.41
Global, days: 90
Region: Foot & ankle

Drawn from CMSFastrvuAAPCFindacodeMdclarity

Documentation requirements

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

Source · Editorial brief grounded in 8 cited references ↓

Diagnosis driving synovectomy — specify the inflammatory or proliferative condition (e.g., rheumatoid arthritis, PVNS, chronic synovitis) with supporting ICD-10 code
Confirmation that the approach is open (arthrotomy), not arthroscopic — operative note must describe incision, capsulotomy, and direct visualization
Extent of synovial tissue resected — partial vs. complete synovectomy affects medical necessity support and distinguishes 27625 from 27626
Laterality documented explicitly (right vs. left ankle) to support LT/RT modifiers required by most MACs
Failed conservative treatment history prior to surgical intervention — payers routinely deny without documented prior management
Pathology specimen disposition if tissue was sent — supports the diagnosis and is expected when PVNS or synovial chondromatosis is suspected

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 LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 8 cited references ↓

CPT 27625 describes an open arthrotomy of the ankle with synovectomy — the surgeon opens the ankle joint and excises the synovial membrane. This is the open version of the procedure; 27626 is used when the approach is more extensive and includes the tendon sheaths. Both carry a 90-day global period.

Synovectomy is typically indicated for inflammatory arthropathies (rheumatoid arthritis, pigmented villonodular synovitis, chronic synovitis) that haven't responded to conservative management. Document the specific pathology driving synovial resection — audit reviewers flag operative notes that lack a diagnosis-to-procedure link when inflammatory joint disease is claimed.

For arthroscopic ankle synovectomy, use 29894 instead. Billing 27625 for a scope-assisted case is a misrepresentation and a common audit target. If you perform open synovectomy alongside another distinct open ankle procedure, modifier 51 applies to the lower-RVU code. Laterality modifiers LT and RT are required by most Medicare Administrative Contractors.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	8.28
Practice expense RVU	6.79
Malpractice RVU	1.34
Total RVU	16.41
Medicare national rate	$548.11
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	$548.11
HOPD (APC 5113) Hospital outpatient department	$3,342.87
ASC (PI A2) Ambulatory surgical center (freestanding)	$1,644.87

Common denial reasons

The recurring reasons claims for CPT 27625 get rejected.

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

Wrong code for arthroscopic approach — billing 27625 when operative note describes a scope-assisted synovectomy (correct code: 29894)
Missing or vague diagnosis linkage — operative notes that don't connect the synovectomy to a specific documented joint pathology are flagged for medical necessity denial
Absent laterality modifier — Medicare and most commercial payers reject ankle surgery claims without LT or RT appended
Insufficient conservative treatment documentation — payers deny when prior non-surgical management (injections, physical therapy, medications) isn't established in the record
Bundling conflict when 27625 is billed same-day with a procedure that includes synovectomy as a component — verify NCCI edits before billing

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 8 cited references ↓

01What's the difference between 27625 and 27626?

27625 is ankle arthrotomy with synovectomy of the joint proper. 27626 extends the synovectomy to include the tendon sheaths. Use 27626 when operative documentation confirms tendon sheath involvement was addressed — don't upcode to 27626 based on diagnosis alone.

02When should I use 29894 instead of 27625?

Use 29894 for arthroscopic ankle synovectomy. If the surgeon used a scope at any point and did not convert to a formal open arthrotomy, 27625 is incorrect. Billing 27625 for an arthroscopic case misrepresents the approach and is a common audit finding.

03Is 27625 ever billed bilaterally on the same date?

Bilateral ankle synovectomy in one session is rare but codeable. Append modifier 50 and confirm the operative note explicitly documents bilateral pathology and bilateral surgical intervention. Some payers require LT and RT on separate lines instead of modifier 50 — check payer-specific rules.

04What modifier applies if 27625 is performed during the global period of a prior ankle surgery?

If the synovectomy is unplanned and related to the prior procedure, use modifier 78. If it's unrelated to the original surgery, use modifier 79. Don't use modifier 58 unless the synovectomy was staged or planned as a follow-on to the original procedure.

05What ICD-10 codes are most commonly paired with 27625?

M06.871 (rheumatoid arthritis, right ankle), M06.872 (left ankle), M12.271–M12.272 (PVNS), M67.371–M67.372 (transient synovitis), and M65.871–M65.872 (synovitis and tenosynovitis) are the primary drivers. The diagnosis must be supported by imaging or prior workup in the record.

06Does the 90-day global period for 27625 include post-op ankle injections or physical therapy?

Routine post-op visits, wound care, and casting are bundled into the global. A corticosteroid injection into the same ankle joint during the 90-day global billed by the operating surgeon requires modifier 79 only if it's truly unrelated. If the injection is treating the surgical site, it's bundled. Physical therapy billed by the surgeon's practice in the global window needs modifier 24 with documentation of a distinct condition.

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 surgical approach (open arthrotomy vs. arthroscopic), the specific ankle pathology documented in the dictation, extent of synovial resection, and laterality — preventing the two most common denials: wrong-code selection (27625 vs. 29894) and missing laterality that triggers MAC auto-rejection.

See how Mira captures CPT 27625 documentation