Open arthrotomy of the elbow joint performed solely to obtain a synovial tissue biopsy for diagnostic purposes.

Verified May 8, 2026 · 6 sources ↓

Medicare: $411.17
Work RVU: 4.94
Global, days: 90
Region: Elbow

Drawn from CMSFastrvuNovitasMdclarity

Documentation requirements

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

Source · Editorial brief grounded in 6 cited references ↓

Operative note must confirm the joint was entered (arthrotomy performed) and that synovial tissue was the sole target of the procedure.
Specify the surgical approach by name — posterior, lateral, medial — not just 'standard approach'; audit teams flag generic approach language.
Pathology requisition and final pathology report must be present to justify the diagnostic intent of the biopsy.
Laterality must be documented (left, right, or bilateral) to support modifier LT, RT, or 50 on the claim.
If modifier 22 is appended, the operative note must describe specific factors that made the procedure substantially more complex than typical — dense adhesions, prior surgery, extreme obesity.
Pre-op diagnosis should support medical necessity — documented joint effusion, inflammatory arthropathy, suspected infection, or other joint pathology requiring tissue confirmation.

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 50 Bilateral procedure 51 Multiple procedures 52 Reduced services 57 Decision for surgery 76 Repeat, same physician 77 Repeat, another 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 24100 covers an open elbow arthrotomy in which the surgeon enters the joint capsule exclusively to harvest synovial tissue for biopsy. The procedure is diagnostic in intent — the tissue is sent to pathology to evaluate for conditions such as rheumatoid arthritis, gout, pigmented villonodular synovitis, or infectious arthritis. It is not coded when synovectomy (debridement or excision of synovium) is performed at the same time; that work escalates to a different code.

The 90-day global period means all routine post-op E/M visits, wound checks, and stitch removals are bundled through day 90. Any E/M during that window for an unrelated condition requires modifier 24. A new, unrelated surgical procedure in the same 90-day period requires modifier 79; an unplanned return to the OR for a related complication requires modifier 78.

Side matters for claims. Append LT or RT to identify which elbow was operated on. If both elbows were biopsied in the same session — uncommon but possible in bilateral inflammatory disease — bill with modifier 50 and document the bilateral indication explicitly in the operative note.

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 (4.94) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (12.31) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	4.94
Practice expense RVU	6.3
Malpractice RVU	1.07
Total RVU	12.31
Medicare national rate	$411.17
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	$411.17
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 24100 get rejected.

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

Missing or mismatched laterality — claim lacks LT/RT modifier or operative note laterality contradicts the billed modifier.
Bundling with a same-day synovectomy code when both open synovial biopsy and synovectomy are performed; only the more extensive procedure should be reported.
Lack of documented medical necessity — no pre-op imaging, labs, or clinical notes supporting the need for open biopsy rather than less invasive diagnostic workup.
E/M billed same-day without modifier 25; a decision-for-surgery visit on the day of 24100 requires modifier 57 if it drove the decision to operate.
90-day global period violations — follow-up E/M visits billed without modifier 24 when the presenting problem is unrelated to the elbow procedure.

Frequently asked questions

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

01Can 24100 be billed with a same-day elbow synovectomy code?

No. If synovectomy is performed at the same operative session, bill only the synovectomy — it is the more extensive service and the biopsy is considered included. Billing both will trigger a bundling denial under NCCI.

02What modifier is required if the surgeon decides to operate during the same-day office visit?

Use modifier 57 on the E/M when that visit represents the decision for surgery for a major procedure with a 90-day global. Modifier 25 applies to minor procedures (10-day or 0-day global), not to 24100.

03Does the pathology report need to be in the chart before billing 24100?

You can bill 24100 once the procedure is complete — you don't need to wait for the pathology result. However, the pathology requisition documenting that tissue was sent supports medical necessity and should be in the record before the claim is submitted.

04How is a bilateral elbow synovial biopsy billed?

Append modifier 50 to 24100 and document bilateral indication in the operative note. Most payers price the second elbow at 50% of the allowed amount for the first. Confirm your specific payer's bilateral payment policy before submitting.

05Is 24100 typically done as an outpatient procedure, and does site of service affect payment?

24100 is performed in both HOPD and ASC settings. The HOPD facility rate and ASC rate differ significantly — see the Site of Service comparison table on this page. The physician professional fee also differs between facility and non-facility settings per CMS PFS 2026 rules.

06What ICD-10 diagnoses most commonly support medical necessity for 24100?

Rheumatoid arthritis of the elbow, crystal-induced arthropathy (gout), pigmented villonodular synovitis, septic arthritis, and unspecified inflammatory arthropathy with joint effusion are the most common supporting diagnoses. The diagnosis code must match the clinical indication documented in the pre-op assessment.

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 by name, confirms synovial biopsy as the sole intraoperative objective, flags laterality, and records any complicating factors (adhesions, prior surgery, anatomic distortion) that support modifier 22. This prevents the two most common audit flags for 24100: operative notes that omit the named approach and notes that fail to distinguish a diagnostic-only biopsy from a concurrent synovectomy.

See how Mira captures CPT 24100 documentation