HPSM Provider Refund Instructions

Providers are required to refund overpayments in accordance with federal and state law, Medi-Cal and Medicare program requirements, and the Health Plan of San Mateo (HPSM) Provider Manual.

When to submit a refund

Submit a refund when your office identifies an overpayment or when HPSM issues an overpayment notice. Providers must not delay refunds while awaiting rebilling unless instructed by HPSM.

Medi-Cal and Medicare requirements

Medi-Cal providers must report and return identified overpayments within 60 calendar days of identification in accordance with California Department of Health Care Services (DHCS) requirements. Medicare CareAdvantage providers must comply with Centers for Medicare & Medicaid Services (CMS) overpayment reporting and refund requirements, including applicable 60-day return timelines.

See HPSM’s PDR processing for disputing an overpayment reported by HPSM.

How to submit a refund

Refunds must be submitted by check unless otherwise directed by HPSM. Checks must be payable to Health Plan of San Mateo. Refunds may not be combined across multiple provider entities or tax identification numbers.

Required documentation

Include provider name, National Provider Identifier (NPI), Federal Tax ID (TIN), claim number(s), member name, date(s) of service, refund amount per claim, and reason for refund. Refunds submitted without sufficient detail may be delayed or returned.

Mailing address

Health Plan of San Mateo
Attention: Provider Refunds
801 Gateway Boulevard, Suite 100
South San Francisco, CA 94080

Important notes

HPSM may offset overpayments against future claim payments when permitted by contract or law. Providers are responsible for retaining proof of refund submission.

Questions

Claims: 650-616-2106 | [email protected]