A9546 — Cobalt co-57/58, cyanocobalamin, diagnostic, per study dose, up to 1 microcurie
A9546 is a HCPCS Level II code for cobalt co-57/58, cyanocobalamin, diagnostic, per study dose, up to 1 microcurie. It belongs to the Transportation, Medical & Surgical Supplies, Administrative section. Whether Medicare pays it depends on the coverage rule below.
Medicare coverage: Carrier judgment
Coverage is decided by your Medicare contractor, not by national policy. Whether this is paid depends on the LCD for your jurisdiction and on what the documentation supports.
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.
Physician fee schedule statusC
Contractor-priced. Your MAC establishes the RVUs and the payment amount case by case, usually after reviewing documentation. There is no national amount to compute.
Global period: XXX
Want the dollar amount for your locality? The fee calculator applies your GPCI and the current conversion factor.
Medically Unlikely Edits — units per day
The most units of A9546 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
- 1 unit MAI 3 — Date of Service Edit: Clinical · Code Descriptor / CPT Instruction
- outpatient
- 1 unit MAI 3 — Date of Service Edit: Clinical · Code Descriptor / CPT Instruction
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 A9546
- Long descriptor
- Cobalt co-57/58, cyanocobalamin, diagnostic, per study dose, up to 1 microcurie
- Short descriptor
- Co57/58
- Added
- January 1, 2006
- BETOS
- I1E
- 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 A9546
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If A9546 is not quite right, the correct code is very often within a few positions of it.
- A9538Technetium tc-99m pyrophosphate, diagnostic, per study dose, up to 25 millicuries
- A9539Technetium tc-99m pentetate, diagnostic, per study dose, up to 25 millicuries
- A9540Technetium tc-99m macroaggregated albumin, diagnostic, per study dose, up to 10 millicuries
- A9541Technetium tc-99m sulfur colloid, diagnostic, per study dose, up to 20 millicuries
- A9542Indium in-111 ibritumomab tiuxetan, diagnostic, per study dose, up to 5 millicuries
- A9543Yttrium y-90 ibritumomab tiuxetan, therapeutic, per treatment dose, up to 40 millicuries
- A9544Iodine i-131 tositumomab, diagnostic, per study doseterminated
- A9545Iodine i-131 tositumomab, therapeutic, per treatment doseterminated
- A9547Indium in-111 oxyquinoline, diagnostic, per 0.5 millicurie
- A9548Indium in-111 pentetate, diagnostic, per 0.5 millicurie
- A9550Technetium tc-99m sodium gluceptate, diagnostic, per study dose, up to 25 millicurie
- A9551Technetium tc-99m succimer, diagnostic, per study dose, up to 10 millicuries
- A9552Fluorodeoxyglucose f-18 fdg, diagnostic, per study dose, up to 45 millicuries
- A9553Chromium cr-51 sodium chromate, diagnostic, per study dose, up to 250 microcuries
- A9554Iodine i-125 sodium iothalamate, diagnostic, per study dose, up to 10 microcuries
- A9555Rubidium rb-82, diagnostic, per study dose, up to 60 millicuries
Questions about A9546
What is HCPCS code A9546?
A9546 is a HCPCS Level II code for cobalt co-57/58, cyanocobalamin, diagnostic, per study dose, up to 1 microcurie. It sits in the Transportation, Medical & Surgical Supplies, Administrative section.
Does Medicare cover A9546?
The CMS HCPCS file marks A9546 as "Carrier judgment". Coverage is decided by your Medicare contractor, not by national policy. Whether this is paid depends on the LCD for your jurisdiction and on what the documentation supports.
How is A9546 paid under the physician fee schedule?
A9546 carries PFS status code C. Contractor-priced. Your MAC establishes the RVUs and the payment amount case by case, usually after reviewing documentation. There is no national amount to compute.