# Check prior authorization requirements
URL: https://backworkhealth.com/docs/api/checkPriorAuth

Evaluate whether procedures require prior authorization based on procedure codes, payer, and state.

**Endpoint:** `POST /api/v1/prior-auth/check`

**Availability:** Live in production.

**Authentication:** API key in `Authorization: Bearer <key>` with the `read` scope.

Evaluate whether procedures require prior authorization based on procedure codes, payer, and state. Without `payer` (or with `payer: Medicare`) it answers for traditional Medicare from LCD/NCD policies in the state's MAC jurisdiction; with a payer it answers from that payer's policies. Returns matched policies, coverage disposition, documentation requirements, and clinical criteria. Codes a policy carries only because its title names the drug come back with `source: inferred_title_match`, cap the confidence, and are named in `known_gaps`. Send `X-Idempotency-Key` to replay the first response for safe retries.

**Parameters**

* `X-Idempotency-Key` (header): Unique key for idempotent requests (recommended for safe retries)
* `procedure_codes` (body, required): CPT/HCPCS codes to check
* `state` (body): Two-letter state code. For Medicare it selects the MAC jurisdiction; for a payer it keeps the payer's policies that apply in that state.
* `payer` (body): Payer name, slug or code, e.g. `Moda Health`, `moda-health` or `MODA`. Omit it, or send `Medicare`, for traditional Medicare LCD, Article and NCD evidence. Any other payer is answered from that payer's own policies.
* `criteria_page` (body): Page number for criteria pagination
* `criteria_per_page` (body): Items per page for criteria

**Code sources:** Code entries in the response carry a `source`: `document` when the policy document lists the code, `inferred_title_match` when the code was attached because the policy title names the drug. See [Code sources](/docs/code-sources).

**Example request**

```bash
curl -X POST "https://backworkhealth.com/api/v1/prior-auth/check" \
  -H "Authorization: Bearer $BACKWORK_API_KEY" \
  -H "X-Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{
  "procedure_codes": [
    "27447"
  ]
}'
```

**Example response** (`200`)

```json
{
  "success": true,
  "data": {
    "pa_required": true,
    "prior_auth_required": true,
    "coverage_status": "covered",
    "confidence": "high",
    "denial_risk": "low",
    "reason": "string",
    "matched_policies": [
      {
        "policy_id": "string",
        "title": "string",
        "policy_type": "string",
        "jurisdiction": "string",
        "source_url": "string",
        "effective_date": "string",
        "last_verified_at": "2026-01-15T10:30:00Z",
        "applicability_scope": "shared_markets",
        "applicability_markets": [
          "string"
        ],
        "applicability_evidence": {
          "document_sha256": "string",
          "market_index_listings": [],
          "document_statements": []
        },
        "applicability_note": "string",
        "public_url": "https://backworkhealth.com/policy/L33831",
        "source_check": {
          "source_url": "https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?lcdid=33831",
          "last_fetched_at": "2026-01-15T10:30:00Z",
          "content_sha256": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
          "source_accuracy": []
        },
        "payer": {
          "name": "string",
          "code": "string",
          "slug": "molina-healthcare"
        },
        "codes": [
          {}
        ]
      }
    ],
    "policy_sources": [
      {
        "source_id": "string",
        "policy_id": "string",
        "title": "string",
        "policy_type": "string",
        "jurisdiction": "string",
        "source_url": "string",
        "effective_date": "string",
        "last_verified_at": "2026-01-15T10:30:00Z",
        "applicability_scope": "shared_markets",
        "applicability_markets": [
          "string"
        ],
        "applicability_evidence": {
          "document_sha256": "string",
          "market_index_listings": [],
          "document_statements": []
        },
        "applicability_note": "string",
        "public_url": "https://backworkhealth.com/policy/L33831",
        "source_check": {
          "source_url": "https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?lcdid=33831",
          "last_fetched_at": "2026-01-15T10:30:00Z",
          "content_sha256": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
          "source_accuracy": []
        },
        "payer": {
          "name": "string",
          "code": "string",
          "slug": "molina-healthcare"
        }
      }
    ],
    "negotiated_rates": {},
    "documentation_checklist": [
      "string"
    ],
    "documentation_requirements": [
      "string"
    ],
    "source_policy_references": [
      {
        "source_id": "string",
        "policy_id": "string",
        "title": "string",
        "policy_type": "string",
        "jurisdiction": "string",
        "source_url": "string",
        "effective_date": "string",
        "last_verified_at": "2026-01-15T10:30:00Z",
        "applicability_scope": "shared_markets",
        "applicability_markets": [
          "string"
        ],
        "applicability_evidence": {
          "document_sha256": "string",
          "market_index_listings": [],
          "document_statements": []
        },
        "applicability_note": "string",
        "public_url": "https://backworkhealth.com/policy/L33831",
        "source_check": {
          "source_url": "https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?lcdid=33831",
          "last_fetched_at": "2026-01-15T10:30:00Z",
          "content_sha256": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
          "source_accuracy": []
        },
        "payer": {
          "name": "string",
          "code": "string",
          "slug": "molina-healthcare"
        }
      }
    ],
    "effective_date": "string",
    "last_verified_at": "2026-01-15T10:30:00Z",
    "requires_manual_review": true,
    "known_gaps": [
      "string"
    ],
    "coverage_decision": {
      "coverage_status": "covered",
      "prior_auth_required": true,
      "documentation_requirements": [
        "string"
      ],
      "denial_risk": "low",
      "policy_sources": [
        {
          "source_id": "string",
          "policy_id": "string",
          "title": "string",
          "policy_type": "string",
          "jurisdiction": "string",
          "source_url": "string",
          "effective_date": "string",
          "last_verified_at": "2026-01-15T10:30:00Z",
          "applicability_scope": "shared_markets",
          "applicability_markets": [],
          "applicability_evidence": {},
          "applicability_note": "string",
          "public_url": "https://backworkhealth.com/policy/L33831",
          "source_check": {},
          "payer": {}
        }
      ],
      "effective_date": "string",
      "last_verified_at": "2026-01-15T10:30:00Z",
      "confidence": "high",
      "requires_manual_review": true,
      "known_gaps": [
        "string"
      ]
    },
    "criteria_details": {
      "indications": [
        {
          "text": "string",
          "tags": [],
          "policy_id": "string"
        }
      ],
      "limitations": [
        {
          "text": "string",
          "tags": [],
          "policy_id": "string"
        }
      ],
      "pagination": {
        "page": 0,
        "per_page": 0,
        "indications": {
          "total": 0,
          "total_pages": 0,
          "has_next": true,
          "has_previous": true
        },
        "limitations": {
          "total": 0,
          "total_pages": 0,
          "has_next": true,
          "has_previous": true
        },
        "documentation": {
          "total": 0,
          "total_pages": 0,
          "has_next": true,
          "has_previous": true
        }
      }
    },
    "mac": {
      "name": "string",
      "jurisdiction": "string",
      "states": [
        "string"
      ]
    }
  },
  "meta": {
    "request_id": "string",
    "timestamp": "2026-01-15T10:30:00Z",
    "idempotency_key": "string",
    "cached": true,
    "attributions": {
      "disclaimer": "string",
      "cpt": "string",
      "loinc": "string",
      "cms": "string",
      "payer_data": "string",
      "negotiated_rates": "string"
    },
    "disclaimer": "string"
  }
}
```