API · Manage · Governance
Link benefit plan.
Record the existence of a benefit plan + its provider linkage. Matter does not administer benefit plans — the plan trust, per-employee elections, premium remittance, and Form 5500/5310 content all live with the record-keeper / benefits administrator / insurance carrier. This endpoint creates the audit-trail record that the plan exists, captures the authorising Resolution, and attaches the linkage Document.
For ERISA-qualified retirement plans (regime: retirement_401k or retirement_403b) the plan trust is a structurally separate legal entity — Matter records the linkage; the record-keeper administers the trust. See api/conventions/payroll-and-benefits-handoff for the boundary in detail.
Last updated
Request Body
application/json
TypeScript Definitions
Use the request body type in TypeScript.
regimestringRequired"medical""dental""vision""life_disability""retirement_401k""retirement_403b""hra""fsa""hsa""other"provider_kindstringRequired"benefits_administrator""retirement_record_keeper""insurance_carrier"provider_namestringOptionalexternal_account_idstringOptionaladoption_resolution_idstringRequiredlinkage_attestation_document_idstringOptionalplan_administrator_stakeholder_idstringOptionalmetadataobjectOptionalFlat string-to-string map. Up to 50 keys. Keys: max 40 chars, charset
[A-Za-z0-9_\\-.]. Values: max 500 chars. Keys prefixed matter_ are reserved
for platform use. Metadata is retrievable but not filterable via query params.
Response Body
application/json
Request
curl -X POST "https://api.mattermode.com/v1/entities/{id}/benefit_plans" \ -H "Content-Type: application/json" \ -d '{ "regime": "medical", "provider_kind": "benefits_administrator", "adoption_resolution_id": "string" }'const body = JSON.stringify({ "regime": "medical", "provider_kind": "benefits_administrator", "adoption_resolution_id": "string"})fetch("https://api.mattermode.com/v1/entities/{id}/benefit_plans", { method: "POST", headers: { "Content-Type": "application/json" }, body})package mainimport ( "fmt" "net/http" "io/ioutil" "strings")func main() { url := "https://api.mattermode.com/v1/entities/{id}/benefit_plans" body := strings.NewReader(`{ "regime": "medical", "provider_kind": "benefits_administrator", "adoption_resolution_id": "string" }`) req, _ := http.NewRequest("POST", url, body) req.Header.Add("Content-Type", "application/json") res, _ := http.DefaultClient.Do(req) defer res.Body.Close() body, _ := ioutil.ReadAll(res.Body) fmt.Println(res) fmt.Println(string(body))}import requestsheaders = { "Authorization": "Bearer sk_test_4eC39HqLyjWDarjtT1zdp7dc", "Matter-Version": "2026-06-10", "Idempotency-Key": "ee7c3a9b-3f1a-4d8e-9b2a-7c5e1f0a2d4b",}payload = { "regime": "medical", "provider_kind": "benefits_administrator", "adoption_resolution_id": "example"}resp = requests.post( "https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/benefit_plans", headers=headers, json=payload,)resp.raise_for_status()print(resp.json())import java.net.URI;import java.net.http.HttpClient;import java.net.http.HttpRequest;import java.net.http.HttpResponse;import java.net.http.HttpResponse.BodyHandlers;import java.time.Duration;import java.net.http.HttpRequest.BodyPublishers;var body = BodyPublishers.ofString("""{ "regime": "medical", "provider_kind": "benefits_administrator", "adoption_resolution_id": "string"}""");HttpClient client = HttpClient.newBuilder() .connectTimeout(Duration.ofSeconds(10)) .build();HttpRequest.Builder requestBuilder = HttpRequest.newBuilder() .uri(URI.create("https://api.mattermode.com/v1/entities/{id}/benefit_plans")) .header("Content-Type", "application/json") .POST(body) .build();try { HttpResponse<String> response = client.send(requestBuilder.build(), BodyHandlers.ofString()); System.out.println("Status code: " + response.statusCode()); System.out.println("Response body: " + response.body());} catch (Exception e) { e.printStackTrace();}using System;using System.Net.Http;using System.Text;var body = new StringContent("""{ "regime": "medical", "provider_kind": "benefits_administrator", "adoption_resolution_id": "string"}""", Encoding.UTF8, "application/json");var client = new HttpClient();var response = await client.PostAsync("https://api.mattermode.com/v1/entities/{id}/benefit_plans", body);var responseBody = await response.Content.ReadAsStringAsync();curl --request POST 'https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/benefit_plans' \ --header 'Authorization: Bearer sk_test_4eC39HqLyjWDarjtT1zdp7dc' \ --header 'Matter-Version: 2026-06-10' \ --header 'Idempotency-Key: ee7c3a9b-3f1a-4d8e-9b2a-7c5e1f0a2d4b' \ --header 'Content-Type: application/json' \ --data '{ "regime": "medical", "provider_kind": "benefits_administrator", "adoption_resolution_id": "example"}'const response = await fetch("https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/benefit_plans", { method: "POST", headers: { "Authorization": "Bearer sk_test_4eC39HqLyjWDarjtT1zdp7dc", "Matter-Version": "2026-06-10", "Idempotency-Key": "ee7c3a9b-3f1a-4d8e-9b2a-7c5e1f0a2d4b", "Content-Type": "application/json", }, body: JSON.stringify({ "regime": "medical", "provider_kind": "benefits_administrator", "adoption_resolution_id": "example" }),});if (!response.ok) { throw new Error(`Matter API ${response.status}: ${await response.text()}`);}const data = await response.json();console.log(data);Response
application/json{
"object": "benefit_plan",
"id": "string",
"entity_id": "string",
"regime": "medical",
"provider_kind": "benefits_administrator",
"provider_name": "string",
"external_account_id": "string",
"linkage_attestation_document_id": "string",
"adoption_resolution_id": "string",
"termination_resolution_id": "string",
"plan_administrator_stakeholder_id": "string",
"status": "linked",
"opened_at": 0,
"terminating_at": 0,
"terminated_at": 0,
"created": 0,
"updated": 0,
"livemode": true
}No example available.