CMS-855I: Medicare Enrollment Application for Individual Physicians and Non-Physician Practitioners
Individual Medicare enrollment vehicle for physicians, NPPs, and certain other individual suppliers; required for any clinician billing Medicare under their own name.
Primary source
CMS-855I Form — CMS.gov →https://www.cms.gov/medicare/cms-forms/cms-forms/downloads/cms855i.pdf
Verified May 23, 2026 · This is the authoritative regulator URL. The summary below is a research aid; the linked source controls.
The CMS-855I is the individual Medicare enrollment application. Required for any physician, non-physician practitioner (NP, PA, CNS, CRNA, CNM, CP, CSW, etc.), or other individual supplier billing Medicare under their own NPI.
Key sections: identifying information and NPI, education and training (board certification), state license history with all license numbers, federal program history (Medicare/Medicaid sanctions, felony convictions, DEA actions), practice locations, billing agencies, and CMS-855R reassignment relationships.
The CMS-855I and CMS-855R are typically filed together when a new physician joins a group: 855I enrolls the individual, 855R reassigns the right to collect Medicare payments from the individual to the group's TIN.
Effective date: the later of (a) the date the application was filed, or (b) the date the physician first met all enrollment requirements (state license, board certification if required, etc.). Practices that delay enrollment risk losing 30+ days of billable services for new hires.
Revalidation occurs every 5 years. The PECOS online filing is preferred over paper; PECOS pre-populates revalidations with currently-on-file data, reducing error.
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Related regulations
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Related across the archive
- 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-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.
- RegulationCMS-855R: Reassignment of Medicare BenefitsAuthorization form for an individual physician/NPP to reassign their right to collect Medicare payment to a group practice or other eligible entity.
- GlossaryCMS-855 (Medicare Enrollment Application)Family of Medicare enrollment applications: 855A (institutional), 855B (group), 855I (individual), 855O (ordering/referring), 855R (reassignment).
- GlossaryCAQH CredentialingThe CAQH ProView database used by most commercial payers to credential providers.
- GlossaryCredentialingThe process by which a payer verifies a provider's qualifications and grants participation in the network.
- GlossaryDeactivationRemoval of a provider from Medicare's enrollment file, typically for failing to revalidate, billing inactivity, or final adverse action.
- GlossaryHospital CredentialingThe process by which a hospital medical staff verifies and grants privileges to a physician.
Last reviewed May 23, 2026 · Citation verified May 23, 2026
Research aid, not legal advice. This summary is an administrative research aid prepared by D3rx. It does not certify compliance, provide legal advice, replace counsel, or guarantee an audit outcome. For authoritative regulatory text follow the primary source link at the top of this page. The practice remains responsible for reviewing, adopting, and maintaining its compliance program.