84155 Assay of protein serum

What 84155 is

CMS fee schedule short descriptor: Assay of protein serum.

Full CPT long descriptions are licensed by the American Medical Association and are not published on this site; the short descriptor above is the one CMS prints in its own fee schedule file. See About CPT.

Medicare payment for 84155 (CY2026)

This code has no Physician Fee Schedule rate: Statutory exclusion - not payable under the Physician Fee Schedule. It may be paid under a different fee schedule (clinical laboratory, DMEPOS, anesthesia) or not paid at all - check the relevant CMS schedule.

Medically Unlikely Edit (MUE)

Medicare caps 84155 at 1 unit per date of service for practitioner claims (MAI 3 - date of service edit (clinical): units above the MUE may pay with documentation on appeal), rationale: Clinical: Data. Units above the cap are denied unless the edit's adjudication rules allow an appeal with documentation.

Billed with 84155? These codes are bundled into it

84155 is a Column 1 code in 2 active NCCI PTP edits. When one of these Column 2 codes is reported on the same date of service, it is denied as bundled - unless the edit's modifier indicator is 1 and documentation supports a distinct service with an NCCI-associated modifier.

84155 is bundled into these codes

84155 appears as a Column 2 code in 3 active edits. Reported with one of these Column 1 codes on the same date of service, 84155 is the code that denies.

Data: CMS CY2026 Physician Fee Schedule RVU file (October release, RVU26D) and Medicare NCCI PTP practitioner edits v32.3 (2026 Q4). Verify against the official files before billing or contracting decisions.