Open ankle joint arthrotomy with exploration, with or without biopsy, with or without removal of a loose or foreign body

Verified May 8, 2026 · 6 sources ↓

Medicare: $435.55
Work RVU: 6
Global, days: 90
Region: Foot & ankle

Drawn from CMSAAPCAbosAcgmeFindacode

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Specify laterality (right vs. left ankle) in the operative note and on the claim
Document the surgical approach and joint entry — 'standard approach' is audit bait; name the capsulotomy site
State explicitly whether biopsy was taken, loose body retrieved, or foreign body removed — even if none were performed, note absence
Record the pre-op diagnosis driving the indication for open exploration vs. arthroscopic approach
Document findings at the time of joint exploration — payer reviewers look for clinical necessity supported by intra-operative findings
Confirm no concurrent arthrocentesis was billed separately, since NCCI bundles 20605 into 27620

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 25 Significant separate E/M 51 Multiple procedures 52 Reduced services 57 Decision for surgery 58 Staged or related 59 Distinct service 76 Repeat, same physician 77 Repeat, another physician 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 27620 covers an open ankle arthrotomy in which the surgeon incises into the joint capsule to directly visualize the ankle joint space. The procedure inherently includes exploration; the surgeon may also take a biopsy specimen, retrieve a loose body, or remove a foreign body — none of those add-ons elevate the code because they're all within the descriptor. This distinguishes 27620 from 27610, which covers exploration and foreign-body removal but not biopsy.

27620 carries a 90-day global period, so all routine post-op care from the day before surgery through day 90 is bundled. Bill modifier 24 for unrelated E&M visits and modifier 79 for unrelated procedures performed during that window. An arthrocentesis (20605) performed at the same operative session is bundled into 27620 per NCCI; don't append a modifier to unbundle it — the joint entry is already captured in the arthrotomy.

Site of service matters here: HOPD and ASC payments differ substantially (see the Site of Service comparison table). Most payers expect this procedure in an ASC or outpatient hospital setting. Document laterality — LT or RT modifier is required for bilateral or unilateral billing to avoid claim rejection on laterality-sensitive edits.

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 (6) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (13.04) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	6
Practice expense RVU	6.01
Malpractice RVU	1.03
Total RVU	13.04
Medicare national rate	$435.55
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	$435.55
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 27620 get rejected.

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

Missing laterality modifier (LT/RT) causes claim rejection on laterality-sensitive edits
Arthrocentesis (20605) billed separately same-day — NCCI bundles it; modifier will not override
Medical necessity denied when documentation lacks a pre-op diagnosis or fails to justify open over arthroscopic approach
Unbundling with 27610 on the same ankle same-day — the two codes are mutually exclusive; bill the one that best describes the procedure performed
Post-op E&M services billed without modifier 24 during the 90-day global period trigger automatic denial

Frequently asked questions

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

01What's the difference between 27610 and 27620?

27610 covers open ankle arthrotomy for exploration, drainage, or foreign-body removal. 27620 adds the option of biopsy. If a biopsy was taken, 27620 is correct. If only exploration or foreign-body removal occurred, either code may apply — but don't bill both for the same ankle on the same date.

02Can I bill 20605 (arthrocentesis) with 27620 on the same day?

No. NCCI bundles 20605 into 27620. The arthrotomy inherently includes joint entry, so the arthrocentesis is not separately reportable. No modifier overrides this edit.

03Does 27620 require a laterality modifier?

Yes. Append LT or RT on every claim. Missing laterality is one of the most common rejection triggers for ankle procedure codes and requires a corrected claim to resolve.

04How does the 90-day global period affect same-day E&M billing?

The global covers the day-before visit, the procedure, and all routine post-op care through day 90. A separately identifiable E&M unrelated to the ankle procedure needs modifier 24 (post-op) or 25 (same-day pre-op decision). Modifier 57 applies if the E&M on the day of or day before surgery was the decision-making visit for a major procedure.

05When is modifier 22 appropriate with 27620?

Modifier 22 applies when the procedure is substantially more complex than typical — for example, dense adhesions from prior surgery, severe deformity, or prolonged operative time with documented justification. The operative note must quantify the added difficulty; a blanket statement of 'difficult case' won't hold up to audit.

06Can 27620 and 27625 (ankle synovectomy) be billed together?

Only if a synovectomy was distinctly performed in addition to the exploration or biopsy. Review current NCCI edits before billing both on the same date — if bundled, modifier 59 or XS may apply, but documentation must support a separate and distinct service.

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 ankle joint entry site, intra-operative findings, whether a biopsy specimen was taken, and whether any loose or foreign body was identified and removed — all from dictation. That specificity prevents the two most common audit flags: operative notes that say 'explored, no loose bodies' without documenting what was actually visualized, and missing laterality that triggers claim-level rejection before a human reviewer ever sees the note.

See how Mira captures CPT 27620 documentation