A9531 HCPCS code: Iodine i-131 sodium iodide, diagnostic, per microcurie (up to 100 microcuries)
A9531 is the HCPCS Level II code for iodine i-131 sodium iodide, diagnostic, per microcurie (up to 100 microcuries). In 2024 Medicare paid an average of $25.78 per service for A9531 across 318 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 100 per day on outpatient hospital claims. Medicare volume fell 3% from 2022 to 2024 (327 to 318 services). In 2024, about 23 clinicians billed Medicare for A9531 for 127 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 | 2004-01-01 |
| Last action effective | 2006-01-01 |
Who bills A9531 (2024)
| Measure | Value |
|---|---|
| Clinicians billing (by place of service) | 23 |
| Medicare beneficiaries | 127 |
| States with claims | 1 |
Counts only. Supplier and clinician names, contact lists and state-by-state detail are in Caduvo.
Medicare utilization for A9531, 2022–2024
| Year | Services | Beneficiaries | Avg. allowed | Avg. paid |
|---|---|---|---|---|
| 2022 | 327 | 129 | $50.89 | $40.61 |
| 2023 | 327 | 141 | $64.82 | $51.37 |
| 2024 | 318 | 127 | $32.61 | $25.78 |
States with the most A9531 services (2024)
| State | Services | Avg. paid |
|---|---|---|
| Maryland | 160 | $12.31 |
NCCI unit limits (MUE)
| Claim type | Max units per day | Rationale |
|---|---|---|
| outpatient hospital claims | 100 | Code Descriptor / CPT Instruction |
| practitioner claims | 100 | Code Descriptor / CPT Instruction |
What changed for A9531
- 2004-01-01: A9531 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 A9531?
A9531 is the HCPCS Level II code for iodine i-131 sodium iodide, diagnostic, per microcurie (up to 100 microcuries). Short descriptor: "I131 max 100uci".
How much does Medicare pay for A9531?
In 2024, the average Medicare payment was $25.78 per service (average allowed $32.61).
Does Medicare cover A9531?
Coverage code C — Carrier judgment. Coverage is decided by the Medicare contractor (MAC) case by case.
How many units of A9531 can be billed per day?
100 on outpatient hospital claims; 100 on practitioner claims (NCCI medically unlikely edits).
Related A95 codes
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- 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
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Next steps
- Run a reimbursement report for a device billed under A9531
- Watch A9531 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for A9531
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.