C2634 — Brachytherapy source, non-stranded, high activity, iodine-125, greater than 1.01 mci (nist), per source
C2634 is a HCPCS Level II code for brachytherapy source, non-stranded, high activity, iodine-125, greater than 1.01 mci (nist), 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 C2634 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
- 24 units MAI 3 — Date of Service Edit: Clinical · Clinical: Data
- outpatient
- 24 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 C2634
- Long descriptor
- Brachytherapy source, non-stranded, high activity, iodine-125, greater than 1.01 mci (nist), per source
- Short descriptor
- Brachytx, non-str, ha, i-125
- Added
- January 1, 2005
- 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 C2634
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If C2634 is not quite right, the correct code is very often within a few positions of it.
- C2624Implantable wireless pulmonary artery pressure sensor with delivery catheter, including all system components
- C2625Stent, non-coronary, temporary, with delivery system
- C2626Infusion pump, non-programmable, temporary (implantable)
- C2627Catheter, suprapubic/cystoscopic
- C2628Catheter, occlusion
- C2629Introducer/sheath, other than guiding, other than intracardiac electrophysiological, laser
- C2630Catheter, electrophysiology, diagnostic/ablation, other than 3d or vector mapping, cool-tip
- C2631Repair device, urinary, incontinence, without sling graft
- 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
- C2642Brachytherapy source, stranded, cesium-131, per source
Questions about C2634
What is HCPCS code C2634?
C2634 is a HCPCS Level II code for brachytherapy source, non-stranded, high activity, iodine-125, greater than 1.01 mci (nist), per source. It sits in the Outpatient Prospective Payment System section.
Does Medicare cover C2634?
The CMS HCPCS file marks C2634 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.