Definition
Provider Directory
A provider directory is a health plan's list of the doctors, hospitals, pharmacies and other providers in its network, showing names, specialties, locations, contact details and, for many listings, whether a provider is accepting new patients.
2 min readReviewed September 14, 2026
Also known as: Health plan provider directory, Network directory, Find a doctor directory, Provider Directory API, Ghost network
Key facts
- Medicare Advantage rules
- 42 CFR 422.111 and 42 CFR 422.120
- Medicaid managed care rules
- 42 CFR 438.10(h)
- Marketplace plan rules
- 45 CFR 156.230
- No Surprises Act
- Verify directory data at least every 90 days; update within 2 business days
- API requirement
- FHIR-based Provider Directory API for Medicare Advantage, Medicaid and CHIP
What is a provider directory?
Members use the directory to find in-network care, and it is often the first place they learn which clinicians their plan covers. Directories are published on websites and apps and, for some plans, in print on request.
A directory is only as accurate as the plan's provider data, which comes from contracts, credentialing files, rosters and updates submitted by practices. When a clinician moves, retires or stops taking new patients and the plan is not told, the listing goes stale.
What federal rules require
Several federal rules set directory requirements:
- Medicare Advantage organizations, Medicaid managed care plans and qualified health plans on the Marketplaces must publish provider directories with specified information under their program rules.
- The CMS Interoperability and Patient Access final rule of 2020 requires Medicare Advantage organizations and Medicaid and CHIP programs and plans to make directory data available through a standards-based Provider Directory API.
- The No Surprises Act, part of the Consolidated Appropriations Act, 2021, requires group health plans and insurers to verify directory information at least every 90 days, update it within 2 business days of receiving a change, and cap cost sharing at in-network levels for members who relied on an incorrect listing. Providers must also submit updates.
Why provider directories matter
Directory accuracy determines whether members can actually get care, and it is central to network adequacy reviews. CMS reviews of Medicare Advantage online directories between 2016 and 2018 found inaccuracies in roughly half of the provider locations checked. Listings of clinicians who do not see plan members, often called ghost networks, have drawn scrutiny from regulators and Congress, particularly in mental health care.
For payer network teams, directory upkeep is a compliance duty and a cost. For analysts, published directories and FHIR APIs show which providers each plan lists as in network, but those listings should be checked against NPPES, claims activity and other sources before being treated as fact.