PECOS (Provider Enrollment System)
Provider Enrollment, Chain, and Ownership System
The CMS online Provider Enrollment, Chain, and Ownership System used to submit and manage Medicare enrollment applications.
1 min read · Last reviewed May 23, 2026
At a glance
- Category
- Enrollment
- Acronym for
- Provider Enrollment, Chain, and Ownership System
- Primary sources
- 2
- Workspace handoff
- compliance binder →
Where this comes up
Credentialing and revenue-cycle staff handle this — CAQH ProView upkeep, payer-roster validation, NPI maintenance, PECOS revalidation cycles, and the gap between application and effective date that strands new providers. Lapses here block payment until backdated re-enrollment closes the gap.
Full definition
What it is in practice
PECOS houses every provider's Medicare enrollment record. NPPES feeds NPI data into PECOS; updates in one do not always sync to the other.
How it shows up in your practice
Maintain PECOS access for at least two staff (one credentialing lead, one backup). Submit changes promptly — the application date often controls effective date.
Sources
- CMS — PECOShttps://pecos.cms.hhs.gov/pecos/login.do
- CMS — Medicare Enrollment Formshttps://www.cms.gov/medicare/enrollment-renewal/providers-suppliers/enrollment-applications
Maintain PECOS access in the Compliance Binder
Open compliance binder →Related terms
- EnrollmentCMS-855 (Medicare Enrollment Application)Family of Medicare enrollment applications: 855A (institutional), 855B (group), 855I (individual), 855O (ordering/referring), 855R (reassignment).
- EnrollmentNPI (National Provider Identifier)The 10-digit HIPAA standard identifier for health care providers.
- EnrollmentProvider Enrollment RevalidationCMS requirement to periodically re-submit and validate enrollment information to remain Medicare-enrolled.
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Related across the archive
- GlossaryCMS-855 (Medicare Enrollment Application)Family of Medicare enrollment applications: 855A (institutional), 855B (group), 855I (individual), 855O (ordering/referring), 855R (reassignment).
- GlossaryProvider Enrollment RevalidationCMS requirement to periodically re-submit and validate enrollment information to remain Medicare-enrolled.
- GlossaryNPI (National Provider Identifier)The 10-digit HIPAA standard identifier for health care providers.
- RegulationCMS-855A: Medicare Enrollment for Institutional ProvidersMedicare enrollment application for institutional providers including hospitals, CAHs, hospices, home health agencies, federally qualified health centers, rural health clinics, and similar entities.
- RegulationCMS-855B: Medicare Enrollment Application for Clinics and Group PracticesThe Medicare enrollment application for clinics, group practices, and certain other suppliers — the primary enrollment vehicle for medical practices that bill Part B.
- RegulationCMS-855I: Medicare Enrollment Application for Individual Physicians and Non-Physician PractitionersIndividual Medicare enrollment vehicle for physicians, NPPs, and certain other individual suppliers; required for any clinician billing Medicare under their own name.
- RegulationCMS-855O: Medicare Enrollment for Eligible Ordering and Certifying Physicians and Other Eligible ProfessionalsAbbreviated Medicare enrollment for clinicians who order or certify items and services for Medicare beneficiaries but do not personally bill Medicare.
- CompliancePECOS Provider Enrollment Verification (2026) — Quarterly ChecklistQuarterly PECOS provider enrollment verification workflow: who to check, the exact lookup steps, the audit log columns, and the revalidation escalation path.
This glossary entry is a research aid for billing and compliance staff. It does not provide legal, medical, or financial advice and does not replace counsel. References cited link to primary sources at HHS, OCR, CMS, eCFR, NIST, and the relevant payer or industry body.