API referenceCoverage
Coverage change feed
GET /v1/coverage/changes
GET https://api.healthcare.dev/v1/coverage/changesPro plan and up (403 plan-upgrade-required below Pro). Material changes to coverage documents as we detect them: a code or diagnosis list, coverage status, an effective or retirement date, or the criteria changed; a document was added or retired. Each event names what changed (fields_changed), the procedure codes whose answers may differ (affected_codes), the effective date and the source page to check (evidence). Formatting-only revisions are never listed. Oldest first by default; order=desc for the most recent first. Page with cursor. The dataset change feed (/v1/changes) lists dataset releases; this one lists source documents.
Requires an API key: Authorization: Bearer hdev_live_.... See Authentication.
Query parameters
| Name | Type | Required | Description | Example |
|---|---|---|---|---|
source_type | "coverage" | no | Kind of source: coverage (more kinds later) | coverage |
payer | string | no | Payer whose documents changed: medicare (more payers later) | medicare |
code | string | no | Only changes affecting this procedure code | 11720 |
since | string (date-time) | no | Only changes detected after this time | |
limit | integer | no | Page size, 1 to 1000 (default 100) | 100 |
order | "asc" | "desc" | no | asc = oldest first (default), desc = newest first | asc |
cursor | string | no | Opaque cursor from links.next | |
view | "compact" | "standard" | "full" | no | How much of each record to return (default full). compact: id, document, change, fields_changed, affected_codes, effective_date (fewest tokens, for agents). standard: every field except type, source_type. full: every field. | compact |
fields | string | no | Comma-separated fields to return instead of a view. Valid fields: id, type, source_type, payer, document, change, kind, fields_changed, affected_codes, affected_dx_count, effective_date, detected_at, evidence. | id,document,change |
Examples
curl
curl "https://api.healthcare.dev/v1/coverage/changes?limit=100" \
-H "Authorization: Bearer $HDEV_API_KEY"TypeScript
const res = await fetch("https://api.healthcare.dev/v1/coverage/changes?limit=100", {
headers: { Authorization: `Bearer ${process.env.HDEV_API_KEY}` },
});
const { data, meta } = await res.json();Python
import os
import requests
res = requests.get("https://api.healthcare.dev/v1/coverage/changes?limit=100", headers={"Authorization": f"Bearer {os.environ['HDEV_API_KEY']}"})
body = res.json()Try it
Response
Material coverage changes
{
"data": [
{
"id": "string",
"type": "coverage.changed",
"source_type": "coverage",
"payer": "string",
"document": {
"id": "string",
"type": "lcd",
"title": "string",
"version_before": 1,
"version_after": 1
},
"change": "added",
"kind": "material",
"fields_changed": [
"document"
],
"affected_codes": [
"string"
],
"affected_dx_count": 1,
"effective_date": "2026-10-01",
"detected_at": "2026-10-24T12:00:00Z",
"evidence": {
"url": "string",
"anchor": "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/coverage/changes?limit=100",
"next": "/v1/coverage/changes?limit=100&cursor=eyJrIjoiRTExLjkifQ"
}
}Fields
| Field | Type | Always present | Description |
|---|---|---|---|
id | string | yes | Stable event id; order by it |
type | "coverage.changed" | yes | |
source_type | "coverage" | yes | |
payer | string | yes | medicare (CMS) for now |
document | object | yes | |
change | "added" | "revised" | "removed" | yes | added: new or newly in effect; removed: retired or withdrawn |
kind | "material" | yes | |
fields_changed | "document" | "status" | "codes" | "dx_supporting" | "dx_not_supporting" | "dx_groups" | "states" | "coverage_level" | "effective_date" | "original_effective_date" | "retire_date" | "criteria" | "coding_rules" | "billing_codes" | "benefit_categories" | "related_documents" | "contractors" | "title" | "revision_history" | "background_text" | "formatting" | "row_order" | "version"[] | yes | |
affected_codes | string[] | yes | Procedure codes whose answers may have changed (identifiers only) |
affected_dx_count | integer | yes | ICD-10-CM codes added to or removed from lists |
effective_date | string | null (date) | yes | |
detected_at | string (date-time) | yes | When we saw the change in the source |
evidence | DerivedEvidence | yes |
Errors
Errors are application/problem+json (RFC 9457). Branch on type, not on title. See 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. |
| 403 | plan-upgrade-required | The plan doesn't include this feature; required_plan names the plan that does. |
| 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. |