A9526 HCPCS code: Nitrogen n-13 ammonia, diagnostic, per study dose, up to 40 millicuries
A9526 is the HCPCS Level II code for nitrogen n-13 ammonia, diagnostic, per study dose, up to 40 millicuries. In 2024 Medicare paid an average of $844.43 per service for A9526 across 2,010 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 61% from 2022 to 2024 (5,203 to 2,010 services). In 2024, about 55 clinicians billed Medicare for A9526 for 1,110 beneficiaries; Florida, New York, Tennessee accounted for 80% of services.
Code details
| Field | Value |
|---|---|
| Section | A codes — Transportation, medical/surgical supplies and miscellaneous |
| Coverage code | C — Carrier judgment |
| Pricing indicator | 53 |
| BETOS category | I1E |
| Added | 2004-01-01 |
| Last action effective | 2006-01-01 |
Who bills A9526 (2024)
| Measure | Value |
|---|---|
| Clinicians billing (by place of service) | 55 |
| Medicare beneficiaries | 1,110 |
| States with claims | 9 |
| Share of services in top 3 states (Florida, New York, Tennessee) | 80% |
Counts only. Supplier and clinician names, contact lists and state-by-state detail are in Caduvo.
Medicare utilization for A9526, 2022–2024
| Year | Services | Beneficiaries | Avg. allowed | Avg. paid |
|---|---|---|---|---|
| 2022 | 5,203 | 2,678 | $643.50 | $513.70 |
| 2023 | 4,995 | 2,588 | $786.08 | $626.25 |
| 2024 | 2,010 | 1,110 | $1,052.63 | $844.43 |
States with the most A9526 services (2024)
| State | Services | Avg. paid |
|---|---|---|
| Florida | 750 | $654.08 |
| New York | 612 | $1,234.51 |
| Tennessee | 236 | $347.50 |
| Nevada | 152 | $588.99 |
| Wisconsin | 83 | $2,336.79 |
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 |
Medicare policy articles for this code
- A56476: Billing and Coding: Cardiac Radionuclide Imaging (Palmetto GBA (MAC - Part A, MAC - Part B))
- A56476: Billing and Coding: Cardiac Radionuclide Imaging (Palmetto GBA (MAC - Part A, MAC - Part B))
Covered diagnoses (635 ICD-10-CM codes)
The diagnoses most often listed as covered in the policy articles above:
| ICD-10-CM | Diagnosis | Articles listing it |
|---|---|---|
| A18.84 | Tuberculosis of heart | 1 |
| C58 | Malignant neoplasm of placenta | 1 |
| C81.10 | Nodular sclerosis Hodgkin lymphoma, unspecified site | 1 |
| C81.11 | Nodular sclerosis Hodgkin lymphoma, lymph nodes of head, face, and neck | 1 |
| C81.12 | Nodular sclerosis Hodgkin lymphoma, intrathoracic lymph nodes | 1 |
| C81.13 | Nodular sclerosis Hodgkin lymphoma, intra-abdominal lymph nodes | 1 |
| C81.14 | Nodular sclerosis Hodgkin lymphoma, lymph nodes of axilla and upper limb | 1 |
| C81.15 | Nodular sclerosis Hodgkin lymphoma, lymph nodes of inguinal region and lower limb | 1 |
| C81.16 | Nodular sclerosis Hodgkin lymphoma, intrapelvic lymph nodes | 1 |
| C81.17 | Nodular sclerosis Hodgkin lymphoma, spleen | 1 |
Showing 10 of 635. The full list, non-covered diagnoses and CSV export are in Caduvo.
What changed for A9526
- 2004-01-01: A9526 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 A9526?
A9526 is the HCPCS Level II code for nitrogen n-13 ammonia, diagnostic, per study dose, up to 40 millicuries. Short descriptor: "Nitrogen n-13 ammonia".
How much does Medicare pay for A9526?
In 2024, the average Medicare payment was $844.43 per service (average allowed $1,052.63).
Does Medicare cover A9526?
Coverage code C — Carrier judgment. Coverage is decided by the Medicare contractor (MAC) case by case.
Which diagnoses support coverage for A9526?
Medicare policy articles that cite A9526 list 635 covered ICD-10-CM diagnosis codes across 2 articles. The most cited include A18.84 (Tuberculosis of heart), C58 (Malignant neoplasm of placenta), C81.10 (Nodular sclerosis Hodgkin lymphoma, unspecified site). A listed diagnosis is necessary but not sufficient; the policy's other criteria still apply.
How many units of A9526 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
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Next steps
- Run a reimbursement report for a device billed under A9526
- Watch A9526 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for A9526
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.