A9521 HCPCS code: Technetium tc-99m exametazime, diagnostic, per study dose, up to 25 millicuries
A9521 is the HCPCS Level II code for technetium tc-99m exametazime, diagnostic, per study dose, up to 25 millicuries. In 2024 Medicare paid an average of $1,366.91 per service for A9521 across 53 services. Its Medicare coverage code is C (Carrier judgment): Coverage is decided by the Medicare contractor (MAC) case by case. The NCCI unit limit is 2 per day on outpatient hospital claims. Medicare volume fell 10% from 2022 to 2024 (59 to 53 services). In 2024, about 14 clinicians billed Medicare for A9521 for 49 beneficiaries.
Code details
| Field | Value |
|---|---|
| Section | A codes — Transportation, medical/surgical supplies and miscellaneous |
| Coverage code | C — Carrier judgment |
| Pricing indicator | 57 |
| BETOS category | I1E |
| Added | 2003-01-01 |
| Last action effective | 2025-01-01 |
Who bills A9521 (2024)
| Measure | Value |
|---|---|
| Clinicians billing (by place of service) | 14 |
| Medicare beneficiaries | 49 |
| States with claims | 2 |
Counts only. Supplier and clinician names, contact lists and state-by-state detail are in Caduvo.
Medicare utilization for A9521, 2022–2024
| Year | Services | Beneficiaries | Avg. allowed | Avg. paid |
|---|---|---|---|---|
| 2022 | 59 | 47 | $1,469.29 | $1,170.63 |
| 2023 | 59 | 55 | $1,677.29 | $1,336.62 |
| 2024 | 53 | 49 | $1,718.62 | $1,366.91 |
States with the most A9521 services (2024)
| State | Services | Avg. paid |
|---|---|---|
| Puerto Rico | 27 | $1,320.02 |
| Arkansas | 11 | $1,743.16 |
NCCI unit limits (MUE)
| Claim type | Max units per day | Rationale |
|---|---|---|
| outpatient hospital claims | 2 | Code Descriptor / CPT Instruction |
| practitioner claims | 2 | Code Descriptor / CPT Instruction |
What changed for A9521
- 2003-01-01: A9521 added to HCPCS Level II
- Next scheduled CMS quarterly update (HCPCS and DMEPOS fee schedule): 2027-01-01
Frequently asked questions
What is HCPCS code A9521?
A9521 is the HCPCS Level II code for technetium tc-99m exametazime, diagnostic, per study dose, up to 25 millicuries. Short descriptor: "Tc99m exametazime".
How much does Medicare pay for A9521?
In 2024, the average Medicare payment was $1,366.91 per service (average allowed $1,718.62).
Does Medicare cover A9521?
Coverage code C — Carrier judgment. Coverage is decided by the Medicare contractor (MAC) case by case.
How many units of A9521 can be billed per day?
2 on outpatient hospital claims; 2 on practitioner claims (NCCI medically unlikely edits).
Related A95 codes
- A9500 — Technetium tc-99m sestamibi, diagnostic, per study dose
- A9501 — Technetium tc-99m teboroxime, diagnostic, per study dose
- A9502 — Technetium tc-99m tetrofosmin, diagnostic, per study dose
- A9503 — Technetium tc-99m medronate, diagnostic, per study dose, up to 30 millicuries
- A9504 — Technetium tc-99m apcitide, diagnostic, per study dose, up to 20 millicuries
- A9505 — Thallium tl-201 thallous chloride, diagnostic, per millicurie
- A9506 — Graphite crucible for preparation of technetium tc 99m-labeled carbon aerosol, one crucible
- A9507 — Indium in-111 capromab pendetide, diagnostic, per study dose, up to 10 millicuries
- A9508 — Iodine i-131 iobenguane sulfate, diagnostic, per 0.5 millicurie
- A9509 — Iodine i-123 sodium iodide, diagnostic, per millicurie
- A9510 — Technetium tc-99m disofenin, diagnostic, per study dose, up to 15 millicuries
- A9512 — Technetium tc-99m pertechnetate, diagnostic, per millicurie
Building a device that would bill under a code like this? Caduvo matches a device description to HCPCS/CPT codes, Medicare coverage and payment, and the FDA pathway in one report.
Next steps
- Run a reimbursement report for a device billed under A9521
- Watch A9521 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for A9521
Sources: CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule; CMS NCCI MUE tables; CMS Medicare utilization (physician and DME supplier files); CMS Medicare Coverage Database articles. Fees are Medicare allowables, not commercial rates. Not billing or legal advice.