Arthroscopic surgery of the subtalar joint that includes excision of inflamed synovial tissue (synovectomy).

Verified May 8, 2026 · 6 sources ↓

Medicare: $477.63
Work RVU: 8.95
Global, days: 90
Region: Foot & ankle

Drawn from CMSAbosCgsmedicareAAPCMdclarity

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Specify the joint entered: subtalar (talocalcaneal), not ankle (tibiotalar/fibulotalar) — payers audit this distinction against 29897/29898.
Document portal placement sites and arthroscopic findings with explicit description of synovial pathology observed.
State that synovectomy was performed and describe extent — partial vs. complete — to support medical necessity.
Include the indication: diagnosis driving synovitis (e.g., inflammatory arthritis, impingement, OA) with corresponding ICD-10 code.
Note laterality (right, left, or bilateral) in both the operative note header and the body of the report.
Document that fluoroscopy, if used intraoperatively, was for guidance only — it cannot be billed separately with this code.

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 AS PA/NP/CNS assistant LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 29905 covers arthroscopic synovectomy of the subtalar joint — the articulation between the talus and calcaneus near the heel. The surgeon introduces an arthroscope through small portals, visualizes the joint, and excises inflamed or hypertrophied synovium. This is distinct from 29904 (loose body removal), 29906 (debridement), and 29907 (subtalar arthrodesis); each represents a separate, more or less involved intervention in the same joint family.

The code carries a 90-day global period. All routine post-op visits, wound checks, and dressing changes through day 90 are bundled. Any unrelated procedure billed within that window requires modifier 79; a related, unplanned return to the OR uses modifier 78. Fluoroscopy used intraoperatively is integral and cannot be separately reported.

Site-of-service distinction matters here. HOPD and ASC payment rates differ significantly — see the site-of-service comparison table on this page. Bilateral subtalar synovectomy is unusual but possible; for professional claims, report modifier 50 on a single line. ASC must use two lines with LT and RT per NCCI bilateral surgery policy.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU vs. total RVU

The work RVU (8.95) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (14.3) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	8.95
Practice expense RVU	4.57
Malpractice RVU	0.78
Total RVU	14.3
Medicare national rate	$477.63
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	$477.63
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI G2) Ambulatory surgical center (freestanding)	$3,695.53

Common denial reasons

The recurring reasons claims for CPT 29905 get rejected.

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

Wrong joint coded: arthroscopy documented in the ankle (tibiotalar) billed as subtalar — mismatched anatomy triggers medical-necessity denial.
Lack of documented synovial pathology: notes that describe only 'joint inspection' without excision findings do not support 29905 over a diagnostic code.
Unbundling fluoroscopy: separately billing intraoperative fluoroscopy with this arthroscopy code violates NCCI policy and will deny.
Global period conflict: post-op E/M visits billed without modifier 24 during the 90-day global period deny as included services.
Missing laterality modifier: some payers require LT or RT on all extremity surgical codes; absence triggers a technical denial.

Frequently asked questions

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

01What separates 29905 from 29906?

29905 is specifically for synovectomy — excision of inflamed synovium. 29906 covers debridement, which is a broader smoothing or removal of damaged tissue. The operative note must match the code: if you excised synovium and also debrided cartilage, review whether 29906 better captures the primary work, or whether both are separately reportable with modifier 59 and NCCI PTP guidance.

02Can I bill 29905 and 29907 together if I performed synovectomy and then arthrodesis at the same session?

Arthrodesis (29907) is a more extensive procedure and typically represents the definitive intervention. Synovectomy performed as part of joint preparation for arthrodesis is generally considered integral. Separately billing 29905 with 29907 at the same session will likely trigger an NCCI PTP edit. Check the current NCCI PTP table before reporting both.

03Is modifier 50 appropriate if I perform bilateral subtalar synovectomy?

For professional claims, yes — append modifier 50 to 29905 on a single line. For ASC facility claims, report two separate lines using LT on one and RT on the other, per NCCI bilateral surgery reporting policy.

04What ICD-10 codes are commonly paired with 29905?

Common diagnoses include M08 (juvenile idiopathic arthritis), M13.871 or M13.872 (other specified arthritis, ankle/foot), M65.871/872 (synovitis and tenosynovitis, ankle/foot), and M19.071/072 (primary osteoarthritis, ankle and foot). Payer LCD policies vary — confirm your MAC's covered diagnosis list before submission.

05How does the 90-day global period affect post-op billing?

All routine follow-up visits related to the subtalar synovectomy through day 90 are bundled into 29905. Bill unrelated E/M services with modifier 24 and document a separate, unrelated chief complaint. A new, unrelated surgical procedure in the same global window uses modifier 79. A related, unplanned return to the OR uses modifier 78.

06Can I separately report intraoperative fluoroscopy with 29905?

No. Per NCCI policy, fluoroscopy used during arthroscopic procedures is integral to the procedure and cannot be billed separately. This rule applies across all arthroscopy codes, including 29905.

Sources & references

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

Mira Scribe

Mira's AI scribe captures joint identification (subtalar vs. tibiotalar), portal sites, arthroscopic findings, extent of synovectomy performed, and laterality directly from dictation. This prevents the most common audit flag for 29905 — operative notes that document ankle arthroscopy findings but are billed under the subtalar code — and ensures ICD-10 diagnosis alignment is present before the claim leaves the practice.

See how Mira captures CPT 29905 documentation