> ## Documentation Index
> Fetch the complete documentation index at: https://stedi.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Coordination of Benefits Check

> Submit a coordination of benefits (COB) check in JSON format

Coordination of benefits (COB) checks help you determine whether patients are covered by multiple health plans, whether coverage overlap requires coordination of benefits, and each payer's responsibility for payment (primacy).

1. Call this endpoint with a JSON payload. Each check **must** be for a Stedi-supported payer with which the patient has coverage. Visit the [Payer Network](https://www.stedi.com/healthcare/network?filter=eyJ0cmFuc2FjdGlvbkZpbHRlcnMiOnsiMjcwIjp7fSwiMjc2Ijp7fSwiODM1Ijp7fSwiODM3UCI6e30sIjgzN0kiOnt9LCI4MzdEIjp7fSwiQ09CIjp7ImlzU3VwcG9ydGVkIjp0cnVlfSwiMjc1VSI6e319LCJjb3ZlcmFnZVR5cGVzIjpbXX0%3D) for a complete list of supported payers.
2. Stedi searches a national database containing 245+ million patient coverage records from 45+ health plans, ASOs, TPAs, and others, including participation from the vast majority of national commercial health plans. Data is updated weekly to ensure accuracy.
3. The endpoint returns information about the patient's active health plans, the responsibility sequence number for each payer if available (such as primary or secondary), and whether coordination of benefits is required.

<Note>
  Visit [Coordination of benefits checks](/healthcare/insurance-discovery) for a full how-to guide.
</Note>