# Reference Data

Several API endpoints require Zocdoc-specific IDs for specialties, visit reasons, and insurance plans. Use the reference data endpoints to retrieve these values programmatically.

In the sandbox environment, reference data is pre-populated with sample records.

## Specialties

Use the [Get Specialties](/apis#operation/getSpecialties) endpoint to retrieve the list of specialties and their Zocdoc IDs. You can optionally filter by care category. To look up a single specialty, use [Get Specialty by ID](/apis#operation/getSpecialtyById).

## Visit Reasons

Use the [Get Visit Reasons](/apis#operation/getVisitReasons) endpoint to retrieve visit reasons and their Zocdoc IDs. You can optionally filter by `specialty_id`. To look up a single visit reason, use [Get Visit Reason by ID](/apis#operation/getVisitReasonById).

## Insurance Plans

Use the [Get Insurance Plans](/apis#operation/getInsurancePlans) endpoint to retrieve available insurance plans. To look up a single plan, use [Get Insurance Plan by ID](/apis#operation/getInsurancePlan).