C2642 — Brachytherapy source, stranded, cesium-131, per source
C2642 is a HCPCS Level II code for brachytherapy source, stranded, cesium-131, per source. It belongs to the Outpatient Prospective Payment System section. Whether Medicare pays it depends on the coverage rule below.
Medicare coverage: Special coverage instructions apply
There are published conditions attached to this code. Check the applicable coverage policy before billing it: the code being valid is not the same as the service being covered.
From the coverage field of the CMS Alpha-Numeric HCPCS File, release 2026Q3-Jul. This states Medicare’s position on the code, not on your particular claim.
Medically Unlikely Edits — units per day
The most units of C2642 Medicare will pay on one date of service. Bill more on a single line and it is denied. The limit is not the same in every setting, so the row that matters is the one matching the claim you are building.
- practitioner
- 120 units MAI 3 — Date of Service Edit: Clinical · Clinical: Data
- outpatient
- 120 units MAI 3 — Date of Service Edit: Clinical · Clinical: Data
The adjudication indicator decides whether exceeding the limit is worth appealing at all: MAI 1 is a line edit you can support with documentation, MAI 3 is a date-of-service edit that is also appealable, and MAI 2 is absolute — no documentation overrides it. CMS MUE 2026Q3.
The CMS record for C2642
- Long descriptor
- Brachytherapy source, stranded, cesium-131, per source
- Short descriptor
- Brachytx, stranded, c-131
- Added
- July 1, 2007
- BETOS
- I4B
- Pricing indicator
- 53 — Other
The official wording. This is what the code means.
CMS's 28-character form, which is what shows up on a remittance advice.
When CMS introduced the code.
Berenson-Eggers Type of Service — CMS's own analytic grouping.
Statute.
Codes adjacent to C2642
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If C2642 is not quite right, the correct code is very often within a few positions of it.
- C2634Brachytherapy source, non-stranded, high activity, iodine-125, greater than 1.01 mci (nist), per source
- C2635Brachytherapy source, non-stranded, high activity, palladium-103, greater than 2.2 mci (nist), per source
- C2636Brachytherapy linear source, non-stranded, palladium-103, per 1 mm
- C2637Brachytherapy source, non-stranded, ytterbium-169, per source
- C2638Brachytherapy source, stranded, iodine-125, per source
- C2639Brachytherapy source, non-stranded, iodine-125, per source
- C2640Brachytherapy source, stranded, palladium-103, per source
- C2641Brachytherapy source, non-stranded, palladium-103, per source
- C2643Brachytherapy source, non-stranded, cesium-131, per source
- C2644Brachytherapy source, cesium-131 chloride solution, per millicurie
- C2645Brachytherapy planar source, palladium-103, per square millimeter
- C2698Brachytherapy source, stranded, not otherwise specified, per source
- C2699Brachytherapy source, non-stranded, not otherwise specified, per source
- C5271Application of low cost skin substitute graft to trunk, arms, legs, total wound surface area up to 100 sq cm; first 25 sq cm or less wound surface areaterminated
- C5272Application of low cost skin substitute graft to trunk, arms, legs, total wound surface area up to 100 sq cm; each additional 25 sq cm wound surface area, or part thereof (list separately in addition to code for primary procedure)terminated
- C5273Application of low cost skin substitute graft to trunk, arms, legs, total wound surface area greater than or equal to 100 sq cm; first 100 sq cm wound surface area, or 1% of body area of infants and childrenterminated
Questions about C2642
What is HCPCS code C2642?
C2642 is a HCPCS Level II code for brachytherapy source, stranded, cesium-131, per source. It sits in the Outpatient Prospective Payment System section.
Does Medicare cover C2642?
The CMS HCPCS file marks C2642 as "Special coverage instructions apply". There are published conditions attached to this code. Check the applicable coverage policy before billing it: the code being valid is not the same as the service being covered.