> ## Documentation Index > Fetch the complete documentation index at: https://docs.cairhealth.com/llms.txt > Use this file to discover all available pages before exploring further. # Real Time Coordination of Benefits Check > Provides coordination of benefits (COB) information for a patient, including primary and secondary insurance details. The following endpoint requires provider enrollment through our platform. Refer to the platform help guides or contact Cair Support with any questions. Use this endpoint to search for health benefit coverage information in the case that a patient has more than one insurance plan. This check can also be performed as part of an eligibility check automatically by setting the `runCobCheck` flag to `true`. #### Possible COB codes | Code | Description | | -------------------------------------- | ----------------------------------------------------------------------------------------------- | | `MemberFoundNoCOB` | No coordination of benefits found for this member | | `CoverageOverlapNoBenefitOverlap` | Multiple coverages found but no overlap in benefits | | `CoverageOverlapExistsNotSubjectToCob` | Coverage overlap exists but is not subject to COB | | `CobInstanceExistsPrimacyUndetermined` | COB exists but primary/secondary status is undetermined. Likely requires a phone call to verify | | `CobInstanceExistsPrimacyDetermined` | COB exists with determined primacy for payer | ## OpenAPI ````yaml POST /api/eligibility/cob/v1 openapi: 3.1.0 info: title: Cair Health APIs description: APIs for the Cair Health platform license: name: MIT version: 1.0.0 servers: - url: https://forecaster.cairhealth.com security: - bearerAuth: [] paths: /api/eligibility/cob/v1: post: description: >- Provides coordination of benefits (COB) information for a patient, including primary and secondary insurance details. requestBody: description: Patient and coverage information for COB check content: application/json: schema: type: object properties: patientFirstName: type: string description: Patient first name patientLastName: type: string description: Patient last name patientDOB: type: string description: Patient Date of Birth, formatted as MM-DD-YYYY optional: true patientMemberId: type: string description: >- Member ID of patient's insurance policy. For a successful check, you MUST provide either the member ID or the SSN. optional: true patientSSN: type: string description: >- Patient's Social Security Number. For a successful check, you MUST provide either the member ID or the SSN. optional: true dateOfCoverage: type: string description: >- Date to request coverage information. Formatted as MM-DD-YYYY payerId: type: string description: >- Payer ID. Can be found under the enrollments page in the platform, or the [Fetch Enrollments](../fetch-enrollments) API providerId: type: string description: >- Provider ID. Can be found by copying the enrollment ID in the enrollments page in the platform, or the [Fetch Enrollments](../fetch-enrollments) API dependentFirstName: type: string description: Dependent's first name if checking coverage for a dependent optional: true dependentLastName: type: string description: Dependent's last name if checking coverage for a dependent optional: true dependentDOB: type: string description: Dependent's Date of Birth, formatted as MM-DD-YYYY optional: true serviceTypeCodes: type: array description: Service type codes to request coverage information for items: type: string optional: true required: - patientFirstName - patientLastName - dateOfCoverage - payerId - providerId example: patientFirstName: John patientLastName: Doe patientDOB: 01-01-1991 patientMemberId: U1234567 dateOfCoverage: 03-24-2025 payerId: HGJLR providerId: 0195b964-5b2c-7bb3-875a-276ad770dc66 required: true responses: '200': description: COB check successful content: application/json: schema: type: object properties: cobCode: type: string description: Code indicating the type of coordination of benefits requestedPlanBenefits: type: array description: Information about the requested plan benefits items: type: object properties: payerName: type: string description: Name of the payer serviceTypeCodes: type: array description: Service type codes and their descriptions items: type: object properties: code: type: string description: Service type code name: type: string description: Description of the service type benefitDate: type: object properties: planStartDate: type: string description: Start date of the plan additionalPlanBenefitInfo: type: array description: Additional information about plan benefits items: type: object properties: payerName: type: string description: Name of the payer payerPrimacy: type: string description: Indicates if this is the primary or secondary payer serviceTypeCodes: type: array description: Service type codes and their descriptions items: type: object properties: code: type: string description: Service type code name: type: string description: Description of the service type benefitDate: type: object properties: overlapBeginDate: type: string description: Start date of benefit overlap overlapEndDate: type: string description: End date of benefit overlap planStartDate: type: string description: Start date of the plan planEndDate: type: string description: End date of the plan coordinationOfBenefits: type: string description: Coordination of benefits date subscriber: type: object properties: firstName: type: string description: Subscriber's first name lastName: type: string description: Subscriber's last name dateOfBirth: type: string description: Subscriber's date of birth memberId: type: string description: Subscriber's member ID example: cobCode: CobInstanceExistsPrimacyDetermined requestedPlanBenefits: - payerName: Blue Cross serviceTypeCodes: - code: '30' name: Health Benefit Plan Coverage benefitDate: planStartDate: '2024-01-01' additionalPlanBenefitInfo: - payerName: Aetna payerPrimacy: SecondaryPayer serviceTypeCodes: - code: '30' name: Health Benefit Plan Coverage benefitDate: overlapBeginDate: '2024-01-01' overlapEndDate: '2024-12-31' planStartDate: '2024-01-01' planEndDate: '2024-12-31' coordinationOfBenefits: '2024-01-01' subscriber: firstName: John lastName: Doe dateOfBirth: '1990-01-01' memberId: W9876543 '400': description: Invalid request body or validation error content: application/json: schema: $ref: '#/components/schemas/Error' '401': description: Unauthorized access or invalid organization ID content: application/json: schema: $ref: '#/components/schemas/Error' '500': description: Server error or provider/payer enrollment issue content: application/json: schema: $ref: '#/components/schemas/Error' security: - bearerAuth: [] components: schemas: Error: type: object properties: message: type: string description: Error message securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT ````