# get_network_groups

Get Network Groups · v0.2.0 · medicare

Which physician groups and health systems a Medicare Advantage contract's published network covers, and how much of each: for a contract and plan year (2026 or 2027), every billing group its listed clinicians bill Medicare through (or every health system of the hospitals they are affiliated with), with the clinicians the contract lists, the group's own clinician count and the share; or search one group or system by name across every contract.

Use cases: 'What share of Virginia Mason's doctors does Regence list?'; 'Which MA contracts list most of Optum's physicians in Texas?'; 'Which large groups does H5938 cover?'.

Groups are CMS's Medicare reassignment (the group a clinician bills through); systems are CMS's hospital affiliation through the hospital system map. A clinician in several groups counts in each. A share is of the group's Medicare-enrolled clinicians, as listed in the plan's published directory. The publish is pinned by dataset_id.

SOURCE: medicare_silver.ma_network_contract_group_v1 (the Data Tracker's directory table x CMS PECOS reassignment x CMS Doctors and Clinicians facility affiliation x the hospital system map).

**Inputs.**
- `contract_id`: CMS contract id (H3817). One of contract_id / name.
- `name`: Billing group or health system name (contains match, e.g. 'Virginia Mason'); searches every contract.
- `plan_year`: 2026 or 2027 (default 2027).
- `level`: 'group' (default; the billing group clinicians reassign to in Medicare) or 'system' (the health system of their hospitals).
- `state`: 2-letter state of the group; optional (groups only).
- `min_clinicians`: Smallest group or system returned, by its own clinician count (default 10).
- `limit`: Rows to return (default 50, max 500).

**Known limits.**
- Groups come from Medicare reassignment: a group's clinicians who do not bill Medicare are not counted.
- Contract level: a contract with several networks (HMO and PPO plans) is read as one.
- Coverage follows the directory build (stage 25); an uncovered contract answers no_coverage.

**A real answer** (customer seat, 1.7 s, args `{"name":"Virginia Mason","min_clinicians":500,"limit":3}`):

```json
{
 "value": {
  "found": false,
  "not_found_reason": "no_row_matches_filters",
  "query": {
   "name": "Virginia Mason",
   "plan_year": 2027,
   "level": "group",
   "min_clinicians": 500,
   "limit": 3
  },
  "dataset_id": "7bceef45cc9e5910e64caa428a1f3e40869f91d149c4e19f08cc55f5e468ba7c",
  "rows": [],
  "query_ids": [
   "7add1d36-0b8a-430f-9532-c0fd2d3afeb0"
  ]
 },
 "unit": "network_groups",
 "vintage": null,
 "source": {
  "dataset": "MA plan networks, 2026 and 2027 (Data Tracker): plan year x CMS plan x NPI x listed location",
  "publisher": "vlada",
  "catalog_updated_at": "2026-11-02"
 },
 "caveats": [],
 "response_hash": "865b1be73ac8247753af5fdf3842c60072ad001422d6e773075a1231685a75b5",
 "semantic_version": 1,
 "tool_version": "get_network_groups@0.2.0",
 "explanation": null,
 "status": "complete",
 "audience": "customer",
 "answer": {
  "value_ref": "value",
  "unit": "network_groups",
  "scope": {
   "tool": "get_network_groups",
   "filters": {
    "name": "Virginia Mason",
    "plan_year": 2027,
    "level": "group",
    "min_clinicians": 500,
    "limit": 3
   }
  }
 },
 "method": "Computed over the filters shown in this answer's scope, from the sources listed in its evidence. Nothing outside those filters was included. You did not specify level; group was used. You did not specify plan_year; 2027 was used.",
 "evidence": {
  "sources": [
   {
    "dataset": "MA plan networks, 2026 and 2027 (Data Tracker): plan year x CMS plan x NPI x listed location",
    "publisher": "vlada",
    "catalog_updated_at": "2026-11-02"
   }
  ],
  "response_hash": "865b1be73ac8247753af5fdf3842c60072ad001422d6e773075a1231685a75b5"
 },
 "defaults_applied": [
  {
   "param": "level",
   "used": "group",
   "reason": "'group' (default"
  },
  {
   "param": "plan_year",
   "used": 2027,
   "reason": "2026 or 2027 (default 2027)."
  }
 ],
 "freshness": {
  "state": "unknown",
  "why": "This tool does not report an edition for its answer, and the door could not derive one from what the answer reads. Treat the result as current to no stated date."
 }
}
```

REST: `POST https://api.vladahealth.com/v1/tools/get_network_groups` with the inputs as the JSON body. MCP: the tool by name.