Surgical opening of a metacarpophalangeal joint with incision into the joint capsule and removal of a synovial tissue sample for pathologic analysis.

Verified May 8, 2026 · 6 sources ↓

Medicare: $340.36
Work RVU: 3.73
Global, days: 90
Region: Hand

Drawn from CMSAAPCCgsmedicareMdclarity

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 exact finger and joint biopsied (e.g., right index MCP joint) — vague 'finger joint' documentation triggers audit flags.
Identify the surgical approach and confirm the joint capsule was entered, not just a periarticular soft tissue excision.
Document the clinical indication driving the biopsy — the diagnostic question must link directly to the ICD-10 code submitted.
Confirm pathology specimen was sent; include the pathology requisition or report reference in the operative note.
Record laterality (right vs. left hand) explicitly to support LT/RT modifier use.
If multiple joints were biopsied in the same session, document each joint separately with individual findings to support per-joint billing.

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 52 Reduced services 58 Staged or related 59 Distinct service 78 Unplanned return — related 79 Unrelated during global LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 6 cited references ↓

CPT 26105 describes an arthrotomy with biopsy of a metacarpophalangeal (MCP) joint — meaning the surgeon opens the joint at the base of a finger, excises a specimen of the synovial lining, and sends it for pathologic evaluation. The code applies per joint; if you biopsy multiple MCP joints in the same session, report it for each with appropriate digit modifiers. It sits in the arthrotomy-with-biopsy family alongside 26100 (carpometacarpal joint) and 26110 (interphalangeal joint) — joint selection drives code selection.

The 90-day global period means routine post-op management through day 90 is bundled. Any unrelated E/M or procedure during that window needs modifier 24 or 79, respectively. The diagnostic purpose of this code — obtaining tissue for pathology — is central to medical necessity justification. ICD-10 diagnosis codes should reflect the clinical question driving the biopsy (e.g., inflammatory arthropathy, suspected synovial neoplasm) rather than a nonspecific joint pain code, which is a common audit trigger.

Site of service matters here: HOPD and ASC payment rates differ substantially (see the Site of Service comparison table). Most volume flows through orthopedic surgery. If the biopsy is performed concurrently with a more extensive procedure on the same joint, NCCI bundling rules may apply — verify the PTP edit pair and confirm whether a modifier can override before billing both codes.

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 (3.73) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (10.19) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	3.73
Practice expense RVU	5.66
Malpractice RVU	0.8
Total RVU	10.19
Medicare national rate	$340.36
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	$340.36
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 26105 get rejected.

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

Nonspecific diagnosis code (e.g., M25.549 — unspecified joint pain) fails to justify biopsy medical necessity; payers expect a specific inflammatory or neoplastic clinical question.
Bundling denial when 26105 is billed same-day with a more comprehensive procedure on the same joint without a valid NCCI PTP modifier.
Missing or mismatched laterality modifier — billing without LT or RT when payer requires anatomic specificity.
Global period conflict when the biopsy follows a prior hand procedure and no modifier 79 (unrelated) or 78 (related complication) is appended.
Lack of pathology documentation — if no specimen was sent or no pathology report exists, payers may downcode or deny as insufficiently supported.

Frequently asked questions

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

01Is 26105 reported per joint or per finger?

Per joint. If you biopsy the MCP joints of two different fingers in the same session, bill 26105 for each with digit-level modifiers to distinguish them. Don't collapse multiple joints into a single unit.

02How does 26105 differ from 26100 and 26110?

Joint anatomy is the differentiator. Use 26100 for carpometacarpal joints, 26105 for metacarpophalangeal joints, and 26110 for interphalangeal joints. The operative note must name the specific joint — audit teams flag notes that don't distinguish between these anatomic levels.

03Can I bill an E/M on the same day as 26105?

Only if the E/M is significant, separately identifiable, and goes beyond the standard pre-op evaluation for this procedure. Append modifier 25 to the E/M. If the visit was solely to decide on surgery, it's bundled — modifier 25 doesn't apply.

04What ICD-10 codes support medical necessity for 26105?

Payers expect a code that reflects a specific diagnostic question — inflammatory arthropathy (e.g., M06.3x for rheumatoid nodule, M05-series for seropositive RA), pigmented villonodular synovitis (M12.2x), or suspected synovial neoplasm. A generic joint pain code will draw scrutiny. Match the ICD-10 to the clinical question documented in the note.

05Does the 90-day global period affect billing for post-op visits after 26105?

Yes. The 90-day global bundles all routine post-op care from the surgery date through day 90. Unrelated E/M visits in that window need modifier 24. A return to the OR for a related complication needs modifier 78; for an unrelated procedure, modifier 79.

06When is modifier 50 appropriate versus separate LT/RT claims?

Modifier 50 signals a bilateral procedure on the same anatomic site on both sides of the body — appropriate if you biopsy the same MCP joint bilaterally (e.g., bilateral index finger MCP joints). Some payers prefer two line items with LT and RT instead of a single line with modifier 50. Check payer-specific instructions before submitting.

Sources & references

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

Mira Scribe

Mira's AI scribe captures the joint name and finger number, laterality, surgical approach, confirmation that the joint capsule was entered, the clinical indication driving the biopsy, and whether a pathology specimen was submitted. This prevents the most common denial pattern for 26105: a nonspecific diagnosis code that fails to justify why a biopsy — rather than imaging or aspiration — was medically necessary.

See how Mira captures CPT 26105 documentation