# Look up a Medicare Part B drug payment limit

URL: https://docs.healthcare.dev/reference/drugs/look-up-a-medicare-part-b-drug-payment-limit

```http
GET https://api.healthcare.dev/v1/drugs/asp/{hcpcs}
```

CMS Medicare Part B drug payment allowance limit (from the quarterly ASP pricing files, generally 106% of average sales price) for one billing code: the newest quarter's limit per `dosage_descriptor` unit, `history` of every quarter loaded (about two years, newest first), `in_effect` (the quarter that applies on `date`, default today), and `ndcs`, the products CMS's NDC-HCPCS crosswalk assigns to the code with billing units per package. CPT codes (vaccines) carry no descriptor (© AMA). A payment limit is not a coverage decision or what a patient pays.

Requires an API key: `Authorization: Bearer hdev_live_...`. See [Authentication](/authentication).

## Path parameters

| Name | Type | Required | Description | Example |
| --- | --- | --- | --- | --- |
| `hcpcs` | string | yes | HCPCS Level II code, or a CPT code number | `J9271` |

## Query parameters

| Name | Type | Required | Description | Example |
| --- | --- | --- | --- | --- |
| `date` | string (date) | no | Answer `in_effect` for this date (YYYY-MM-DD; default today) | `2026-08-15` |
| `view` | "compact" \| "standard" \| "full" | no | How much of each record to return (default `full`). `compact`: `hcpcs`, `short_description`, `quarter`, `payment_limit`, `dosage_descriptor`, `in_effect`, `status`, `on_date`, `in_effect`, `ndc_count`, `matched_ndcs`, `match_score` (search results) (fewest tokens, for agents). `standard`: every field except `history`, `ndcs`. `full`: every field. | `compact` |
| `fields` | string | no | Comma-separated fields to return instead of a view. Valid fields: `hcpcs`, `code_system`, `short_description`, `quarter`, `effective_from`, `effective_through`, `payment_limit`, `dosage_descriptor`, `coinsurance_percentage`, `vaccine_awp_percent`, `vaccine_limit`, `blood_awp_percent`, `blood_limit`, `clotting_factor`, `notes`, `history`, `ndcs`, `status`, `effective_start`, `effective_end`, `replaced_by`, `on_date`, `in_effect`, `ndc_count`, `matched_ndcs`, `match_score` (search results). | `hcpcs,short_description,quarter` |

## Examples

**curl**

```sh
curl "https://api.healthcare.dev/v1/drugs/asp/J9271" \
  -H "Authorization: Bearer $HDEV_API_KEY"
```

**TypeScript**

```ts
const res = await fetch("https://api.healthcare.dev/v1/drugs/asp/J9271", {
  headers: { Authorization: `Bearer ${process.env.HDEV_API_KEY}` },
});
const { data, meta } = await res.json();
```

**Python**

```python
import os
import requests

res = requests.get("https://api.healthcare.dev/v1/drugs/asp/J9271", headers={"Authorization": f"Bearer {os.environ['HDEV_API_KEY']}"})
body = res.json()
```

## Response

The payment limit, its history and crosswalked NDCs

```json
{
  "data": {
    "hcpcs": "string",
    "code_system": "hcpcs",
    "short_description": "string",
    "quarter": "string",
    "effective_from": "2026-10-01",
    "effective_through": "2026-10-01",
    "payment_limit": 0,
    "dosage_descriptor": "string",
    "coinsurance_percentage": 0,
    "vaccine_awp_percent": 1,
    "vaccine_limit": 0,
    "blood_awp_percent": 1,
    "blood_limit": 0,
    "clotting_factor": true,
    "notes": "string",
    "history": [
      {
        "quarter": "string",
        "effective_from": "2026-10-01",
        "effective_through": "2026-10-01",
        "payment_limit": 0,
        "dosage_descriptor": "string",
        "coinsurance_percentage": 0,
        "vaccine_awp_percent": 1,
        "vaccine_limit": 0,
        "blood_awp_percent": 1,
        "blood_limit": 0,
        "clotting_factor": true,
        "notes": "string"
      }
    ],
    "ndcs": [
      {
        "ndc": "string",
        "ndc11": "string",
        "labeler": "string",
        "drug_name": "string",
        "hcpcs_dosage": "string",
        "package_size": 1,
        "package_quantity": 1,
        "billing_units": 1,
        "billing_units_per_package": 1,
        "quarters": [
          null
        ]
      }
    ],
    "status": "active",
    "effective_start": "2026-10-01",
    "effective_end": "2026-10-01",
    "replaced_by": [
      "string"
    ],
    "on_date": "2026-10-01",
    "in_effect": {
      "quarter": "string",
      "effective_from": "2026-10-01",
      "effective_through": "2026-10-01",
      "payment_limit": 0,
      "dosage_descriptor": "string",
      "coinsurance_percentage": 0,
      "vaccine_awp_percent": 1,
      "vaccine_limit": 0,
      "blood_awp_percent": 1,
      "blood_limit": 0,
      "clotting_factor": true,
      "notes": "string"
    }
  },
  "meta": {
    "source": "cms-icd10",
    "data_version": "2026.1",
    "retrieved_at": "2026-10-24T12:00:00Z",
    "license": "Public domain (CMS). Reference data, not medical advice."
  },
  "links": {
    "self": "/v1/drugs/asp/J9271",
    "next": null
  }
}
```

### Fields

| Field | Type | Always present | Description |
| --- | --- | --- | --- |
| `hcpcs` | string | yes | Billing code: HCPCS Level II (e.g. `J9271`), or a CPT code number for vaccines |
| `code_system` | "hcpcs" \| "cpt" | yes | `cpt` for CPT code numbers (vaccines, immune globulins): their descriptors are © AMA and never included |
| `short_description` | string \| null | yes | CMS's HCPCS Level II short descriptor; always null for CPT codes |
| `quarter` | string | yes | Calendar quarter, as its first month (`2026-10` = October to December 2026) |
| `effective_from` | string (date) | yes | First day the payment limit applies |
| `effective_through` | string (date) | yes | Last day the payment limit applies (inclusive) |
| `payment_limit` | number \| null | yes | Medicare Part B payment allowance limit, USD per `dosage_descriptor` unit (generally 106% of ASP); null where CMS lists none (`N/A`) |
| `dosage_descriptor` | string \| null | yes | The billing unit the limit is per, as CMS lists it, e.g. `10 MG`, `1 ML` |
| `coinsurance_percentage` | number \| null | yes | Beneficiary coinsurance, percent (20 unless reduced, e.g. inflation-adjusted coinsurance) |
| `vaccine_awp_percent` | number \| null | yes | Vaccines priced at a percent of AWP |
| `vaccine_limit` | number \| null | yes |  |
| `blood_awp_percent` | number \| null | yes | Blood products priced at a percent of AWP |
| `blood_limit` | number \| null | yes |  |
| `clotting_factor` | boolean | yes | Clotting factor: the separate furnishing fee applies on top of the limit |
| `notes` | string \| null | yes | CMS's note, e.g. `Added October 2026` |
| `history` | AspQuarter[] | yes | Every quarter in the files loaded (about two years), newest first; the newest is also flattened above. The limit in effect on a date is the entry whose effective_from..effective_through contains it. |
| `ndcs` | AspNdc[] | yes | NDCs the ASP NDC-HCPCS crosswalk assigns to this code in any quarter loaded |
| `status` | "active" \| "retired" \| "replaced" | yes |  |
| `effective_start` | string (date) | yes |  |
| `effective_end` | string \| null (date) | yes |  |
| `replaced_by` | string[] | no |  |
| `on_date` | string (date) | yes | The date `in_effect` answers for (`?date=`, default today, UTC) |
| `in_effect` | object \| null | yes | The quarter whose payment limit applies on `on_date`, or null when no loaded quarter covers it (a future date before CMS posts that quarter, or a date older than the history kept) |

## Errors

Errors are `application/problem+json` ([RFC 9457](https://www.rfc-editor.org/rfc/rfc9457)). Branch on `type`, not on `title`. See [Errors](/errors).

| Status | `type` | When |
| --- | --- | --- |
| 400 | `invalid-request` | A parameter or the body failed validation; `errors` lists each field. |
| 401 | `unauthorized` | Missing, malformed or revoked API key. |
| 404 | `not-found` | No record with that id (retired records are still returned). |
| 429 | `rate-limited / quota-exceeded` | Too many requests per second (retry after `Retry-After`), or the monthly quota is used up. |
| 503 | `dataset-unavailable / unavailable` | The dataset has no published version yet, or the service is degraded. |