> ## Documentation Index > Fetch the complete documentation index at: https://docs.rcintell.com/llms.txt > Use this file to discover all available pages before exploring further. # Look up a denial code for a specific payer > Get denial pattern data for a specific denial code at a specific payer. ## OpenAPI ````yaml /docs/openapi.client.json get /v1/payers/{slug}/denial-codes/{code} openapi: 3.1.0 info: description: >- Client API for RCIntel. Admin ingest, catalog sync, and internal audit routes are omitted. See Guides → Which API to use. summary: Multi-tenant knowledge API for healthcare revenue cycle management. title: Healthcare Knowledge Layer version: 0.1.0 servers: [] security: [] tags: - description: >- Geographic payer policy lookup (national NCD vs MAC LCD vs state). Query payer, code, state, plan_type. Each row includes geo_scope and document_version. name: policies - description: >- Payer network directory — search payers, check prior auth requirements, view filing rules, denial patterns, and appeal levels. name: payers - description: >- Resolve healthcare billing knowledge across the L1-L6 layer stack. Includes payment calculation, billing guidance, and per-layer queries. name: knowledge - description: >- CMS Fee Schedule lookups — OPPS (Addendum B / APC), DMEPOS (state-level pricing), and Clinical Lab Fee Schedule (CLFS). name: fee-schedules - description: >- NCCI (National Correct Coding Initiative) — dedicated MUE limits, PTP bundling edits, add-on code edits, and code pair validation. name: ncci - description: >- Service code intelligence — CPT/HCPCS lookup, RVU data, NCCI edits, payment calculation, implant/GUDID search, and service group classification. name: codes - description: >- Submit asynchronous AI agent jobs for code research, medical necessity, and denial resolution. Poll for results and retrieve reasoning traces. name: agents - description: >- Register and manage healthcare facilities by CCN (Medicare Provider Number). Each facility is the root entity for knowledge resolution. name: facilities - description: >- NPI Registry — live search against CMS NPPES API for provider and organization National Provider Identifiers. name: npi - description: >- OpenFDA drug product lookup by NDC. Includes product-level fields with normalized ingredient and package detail. name: drugs - description: Health checks, service metadata, and Prometheus metrics. name: system paths: /v1/payers/{slug}/denial-codes/{code}: get: tags: - payers summary: Look up a denial code for a specific payer description: Get denial pattern data for a specific denial code at a specific payer. operationId: get_denial_code_v1_payers__slug__denial_codes__code__get parameters: - description: Normalized payer slug identifier. in: path name: slug required: true schema: title: Slug type: string - description: >- Billing or terminology code value (CPT/HCPCS/NDC/etc depending on endpoint context). in: path name: code required: true schema: title: Code type: string responses: '200': content: application/json: schema: $ref: '#/components/schemas/DenialCodeLookupResponse' description: Successful Response '422': content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' description: Validation Error security: - APIKeyHeader: [] components: schemas: DenialCodeLookupResponse: description: Denial code resolution across one or all payers. properties: denial_code: title: Denial Code type: string payer_count: default: 0 description: Number of payers with data for this code title: Payer Count type: integer reliability: $ref: '#/components/schemas/ReliabilityMetadata' description: User-visible reliability metadata for denial lookup resolution. results: items: $ref: '#/components/schemas/DenialPatternResponse' title: Results type: array total_results: default: 0 title: Total Results type: integer x12_master: description: X12 master CARC metadata from the pipeline-backed catalog. items: $ref: '#/components/schemas/X12MasterDenialResponse' title: X12 Master type: array required: - denial_code title: DenialCodeLookupResponse type: object HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' title: Detail type: array title: HTTPValidationError type: object ReliabilityMetadata: description: User-visible reliability metadata attached to API responses. properties: data_sources: additionalProperties: type: string description: Data-source backends used to build this response. title: Data Sources type: object dataset_versions: additionalProperties: type: string description: >- CMS/DHCS/NLM/FDA named versions used to compose this response (e.g. mpfs=CY2026, ipps=FY2026). See GET /v1/data/changes. title: Dataset Versions type: object degraded: default: false description: True when a fallback or non-primary source path was used. title: Degraded type: boolean generated_at: description: UTC timestamp when the response payload was composed. title: Generated At type: string warnings: description: Human-readable caveats relevant to downstream consumers. items: type: string title: Warnings type: array required: - generated_at title: ReliabilityMetadata type: object DenialPatternResponse: properties: auto_appealable: default: false title: Auto Appealable type: boolean avg_resolution_days: anyOf: - type: integer - type: 'null' title: Avg Resolution Days denial_category: anyOf: - type: string - type: 'null' title: Denial Category denial_code: anyOf: - type: string - type: 'null' title: Denial Code documentation_needed: items: type: string title: Documentation Needed type: array frequency_rank: anyOf: - type: integer - type: 'null' title: Frequency Rank remark_code: anyOf: - type: string - type: 'null' title: Remark Code resolution_steps: items: type: string title: Resolution Steps type: array root_cause: anyOf: - type: string - type: 'null' title: Root Cause success_rate: anyOf: - type: number - type: 'null' title: Success Rate title: DenialPatternResponse type: object X12MasterDenialResponse: description: X12 master catalog row for a CARC denial code. properties: carc_code: title: Carc Code type: string carc_description: title: Carc Description type: string effective_date: anyOf: - type: string - type: 'null' title: Effective Date group_code: anyOf: - type: string - type: 'null' title: Group Code group_description: anyOf: - type: string - type: 'null' title: Group Description last_modified: anyOf: - type: string - type: 'null' title: Last Modified notes: anyOf: - type: string - type: 'null' title: Notes required: - carc_code - carc_description title: X12MasterDenialResponse type: object ValidationError: properties: ctx: title: Context type: object input: title: Input loc: items: anyOf: - type: string - type: integer title: Location type: array msg: title: Message type: string type: title: Error Type type: string required: - loc - msg - type title: ValidationError type: object securitySchemes: APIKeyHeader: in: header name: X-API-Key type: apiKey ````