A9591 HCPCS code: Fluoroestradiol f 18, diagnostic, 1 millicurie
A9591 is the HCPCS Level II code for fluoroestradiol f 18, diagnostic, 1 millicurie. In 2024 Medicare paid an average of $724.13 per service for A9591 across 1,308 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 6 per day on outpatient hospital claims. Medicare volume rose 293% from 2022 to 2024 (333 to 1,308 services). In 2024, about 106 clinicians billed Medicare for A9591 for 216 beneficiaries; California, Florida, New York accounted for 75% of services.
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 | 2021-01-01 |
| Last action effective | 2025-01-01 |
Who bills A9591 (2024)
| Measure | Value |
|---|---|
| Clinicians billing (by place of service) | 106 |
| Medicare beneficiaries | 216 |
| States with claims | 6 |
| Share of services in top 3 states (California, Florida, New York) | 75% |
Counts only. Supplier and clinician names, contact lists and state-by-state detail are in Caduvo.
Medicare utilization for A9591, 2022–2024
| Year | Services | Beneficiaries | Avg. allowed | Avg. paid |
|---|---|---|---|---|
| 2022 | 333 | 56 | $741.68 | $591.64 |
| 2023 | 702 | 125 | $860.34 | $685.47 |
| 2024 | 1,308 | 216 | $909.20 | $724.13 |
States with the most A9591 services (2024)
| State | Services | Avg. paid |
|---|---|---|
| California | 405 | $655.75 |
| Florida | 229 | $602.04 |
| New York | 188 | $706.20 |
| Arizona | 150 | $652.17 |
| Massachusetts | 95 | $629.86 |
NCCI unit limits (MUE)
| Claim type | Max units per day | Rationale |
|---|---|---|
| outpatient hospital claims | 6 | Prescribing Information |
| practitioner claims | 6 | Prescribing Information |
What changed for A9591
- 2021-01-01: A9591 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 A9591?
A9591 is the HCPCS Level II code for fluoroestradiol f 18, diagnostic, 1 millicurie. Short descriptor: "Fluoroestradiol f 18".
How much does Medicare pay for A9591?
In 2024, the average Medicare payment was $724.13 per service (average allowed $909.20).
Does Medicare cover A9591?
Coverage code C — Carrier judgment. Coverage is decided by the Medicare contractor (MAC) case by case.
How many units of A9591 can be billed per day?
6 on outpatient hospital claims; 6 on practitioner claims (NCCI medically unlikely edits).
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Next steps
- Run a reimbursement report for a device billed under A9591
- Watch A9591 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for A9591
Sources: CMS HCPCS Level II release October 2025; 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.