Medicare enrollment with PECOS
Medicare enrollment with PECOS refers to registering a provider or supplier with the Medicare program through the Provider Enrollment, Chain, and Ownership System (PECOS), the online system the Centers for Medicare & Medicaid Services (CMS) uses to collect, validate, and maintain enrollment records. A completed enrollment establishes a provider's eligibility to bill Medicare and to order, refer, or certify covered items and services. It is a distinct step from credentialing and from commercial payer contracting, each of which follows its own rules that vary by payer, plan, and jurisdiction.
Updated 8 min read
Reviewed by Anwaar Tayyab
Director of Billing Operations ·
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Key takeaways
- PECOS is the CMS online system for Medicare provider and supplier enrollment, mirroring the paper CMS-855 application family.
- An active NPI from NPPES and an Identity & Access (I&A) account are prerequisites before an enrollment can be submitted in PECOS.
- The correct application depends on whether enrollment is individual, organizational or group, or solely to order and certify; reassignment of benefits is reported on the individual application.
- Enrollment is not permanent; CMS requires periodic revalidation and prompt reporting of changes on cycles it defines.
- Effective-date, application-fee, and processing rules vary by application type and change over time, so the current CMS source is authoritative.
What PECOS is
PECOS is the electronic system CMS maintains for Medicare provider enrollment. It is the online counterpart to the paper CMS-855 forms: a provider or an authorized organization uses it to submit an initial enrollment, add or change practice locations, reassign benefits, revalidate, or voluntarily withdraw. Applications submitted through PECOS are routed to the appropriate Medicare Administrative Contractor (MAC), which processes them by geographic jurisdiction and provider type.
Enrollment is often confused with credentialing, but the two answer different questions. Credentialing and primary source verification confirm that a practitioner's licensure, education, and history are what they claim to be. Enrollment registers that practitioner or entity with a specific program — here, Medicare — so that claims can be adjudicated and paid. The distinction is covered in more depth in credentialing vs. enrollment.
Enrollment establishes billing privileges, not clinical judgment
What must be in place first
Before an enrollment can be filed, a few foundational records must already exist. CMS expects the legal name carried in NPPES and the name on the Medicare enrollment record to match, and incorrect data in either system can prompt unnecessary inquiries about a provider's credentials.
- National Provider Identifier (NPI)
- A ten-digit identifier obtained from NPPES that must be active before enrollment; it links the enrollment record to the individual or organization.
- NPPES record
- The National Plan and Provider Enumeration System record behind the NPI; CMS requires the legal business name and the individual provider's name to match between NPPES and the Medicare enrollment record.
- Identity & Access (I&A) account
- The CMS access-management registration that authenticates the individual and establishes authorized officials and delegated users who may act for an organization in PECOS.
Note that Medicare enrollment does not run on a CAQH profile. The CAQH provider data profile is attested by the clinician and shared with the health plans that clinician participates in, for credentialing and directory work rather than for Medicare fee-for-service enrollment, as described in the CAQH profile. A provider preparing to work across Medicare and health plan networks generally maintains both a PECOS enrollment and a CAQH profile, because each relies on its own system of record.
Choosing the right application
PECOS carries the same set of applications as the paper CMS-855 application family. Which one applies depends on who is enrolling and why — an individual practitioner, an organization, or an enrollment made solely to order and certify. Reassignment of the right to bill is not a separate form: CMS merged the CMS-855R into the CMS-855I, and reassignments are now added, changed, or terminated on that application or in PECOS. The choice between filing as an individual and enrolling through a group is explored in individual vs. group enrollment.
| Application | Typically filed by | Primary purpose |
|---|---|---|
| CMS-855I | An individual physician or non-physician practitioner | Enroll an individual to obtain Medicare billing privileges, and report reassignment of benefits. |
| CMS-855B | A clinic, group practice, or certain organizational suppliers | Enroll an organization that is not an institutional provider. |
| CMS-855A | An institutional provider such as a hospital or home health agency | Enroll an institutional provider with Medicare. |
| CMS-855O | A physician or non-physician practitioner who orders or certifies but does not bill | Enroll solely to order and certify, without submitting claims. |
CMS assigns and periodically updates these forms, and separate items such as the CMS-588 electronic funds transfer authorization and the CMS-460 participating agreement may accompany an enrollment. Confirm current forms and requirements with CMS, as they vary by provider type and change over time.
How enrollment moves through PECOS
The workflow is broadly consistent across application types, though the exact screens, supporting documents, and review steps differ. The sequence below describes the general path; the range of routes into Medicare and other programs is outlined in enrollment pathways.
Confirm identifiers and access
Verify that the NPI is active and the NPPES record is accurate, and confirm that the correct I&A roles are in place for whoever will submit.Select and complete the application
Choose the application that matches the enrolling party and purpose, then enter practice locations, specialties, ownership, and managing information as prompted.Attach supporting documentation
Provide the licenses, agreements, and any application fee or fee-waiver information the specific application requires; requirements vary by provider type.Sign and submit
An authorized official or the individual electronically signs; some submissions also generate certification documents that must be signed and returned.MAC review and determination
The Medicare Administrative Contractor reviews the application, may request corrections, and issues an approval or denial. Timeframes vary by MAC, workload, and application type.
Effective dates and what enrollment enables
An approved enrollment carries an effective date that governs the earliest date of service Medicare will consider for payment. CMS applies specific rules to that date, and for some provider and supplier types allows limited retrospective billing for services furnished before it. Those rules differ by application type and are periodically revised, so the current CMS guidance and the sibling article on effective dates should be treated as authoritative rather than any fixed number of days.
Enrollment scope also extends beyond billing. For certain ordered items and services — imaging, clinical laboratory services, and durable medical equipment, prosthetics, orthotics, and supplies (DMEPOS) — and for home health and hospice certifications, the ordering or certifying practitioner must be identified on the claim by legal name and NPI and must themselves be enrolled in Medicare in an approved status or have validly opted out. Otherwise the billing provider's claim is not payable, even though that provider is properly enrolled. This is why an enrollment made solely to order and certify exists as a distinct option.
Billing before an effective date is a common exposure
Keeping an enrollment current
A Medicare enrollment is a living record. CMS requires that changes be reported within its stated timeframes and that providers periodically confirm their information through revalidation. Letting a record lapse can interrupt billing privileges, so ongoing maintenance is part of the process, not an afterthought — see revalidation and recredentialing and enrollment maintenance for the broader cadence.
- Report changes of address, ownership, managing employees, or reassignments within the window CMS specifies.
- Respond to revalidation notices by the due date CMS assigns; cycles are set by CMS and differ for certain supplier types such as DMEPOS.
- Keep the NPPES record and the enrollment aligned, since updating an NPI record in NPPES does not automatically update the Medicare enrollment record.
- Track any application fee obligations, which apply to certain institutional and supplier applications and are adjusted by CMS over time.
Providers serving other public programs manage a parallel process; state Medicaid programs run their own enrollment and revalidation, described in Medicaid provider enrollment. Requirements there vary by state and should not be assumed to mirror Medicare.
Common questions
Is Medicare enrollment the same as credentialing?
No. Credentialing verifies a provider's qualifications, licensure, and history through primary source verification. Enrollment registers the provider or organization with the Medicare program so claims can be processed and paid. A provider may be credentialed by an organization yet still need a separate Medicare enrollment through PECOS.
Do providers still use paper CMS-855 forms?
PECOS is the online alternative to the paper CMS-855 applications and is generally the faster route, but paper forms exist for the same purposes. CMS determines which methods are available for a given application type, so the current CMS guidance is the authoritative source.
Is an NPI required before enrolling in PECOS?
Yes. An active National Provider Identifier from NPPES is a prerequisite, and the enrollment data should match the NPPES record. The legal business name and the individual provider's name must match between the two systems, and updating an NPI record in NPPES does not automatically update the Medicare enrollment record.
Does Medicare enrollment require a CAQH profile?
No. Medicare enrollment runs through PECOS, not CAQH. The CAQH provider data profile is attested by the clinician and shared with the health plans that clinician participates in, for credentialing and directory work. Providers who work across Medicare and health plan networks typically maintain both, because each relies on its own system of record.
How often must a Medicare enrollment be revalidated?
CMS sets revalidation cycles and notifies providers when they are due. Cycles differ by provider and supplier type, with certain suppliers such as DMEPOS on a shorter cycle. Because these schedules are defined and updated by CMS, the current CMS revalidation notice should be treated as authoritative.
Key terms in this article
Defined once, on their own pages.
Continue learning
Where to go next within credentialing and payer enrollment.
The CMS-855 application family
How the individual, organizational, and ordering-and-certifying applications differ.
Individual vs. group enrollment
When a practitioner enrolls as an individual versus billing through a group.
Credentialing vs. enrollment
Why verifying qualifications and registering with a payer are separate steps.
Revalidation and recredentialing
Keeping enrollment and credentialing records current over time.
Provider enrollment
The foundational glossary definition behind Medicare and commercial enrollment.
Authoritative sources
- Provider Enrollment, Chain, and Ownership System (PECOS) Fact Sheet (opens in a new tab)
CMS. Describes PECOS as the web-based platform CMS manages for Medicare provider and supplier enrollment, states that a user signs in with an Identity & Access (I&A) Management System user ID and password, and warns that the legal business name and individual provider's name must match between NPPES and PECOS because an NPPES update does not carry across to the Medicare enrollment record.
- Medicare enrollment applications (opens in a new tab)
CMS. Lists the current paper enrollment forms by enrolling party — CMS-855A, CMS-855B, CMS-855I, CMS-855O, CMS-855S, and CMS-20134 — with no CMS-855R, and names the CMS-588 electronic funds transfer authorization and the CMS-460 participating agreement as the forms routinely submitted with an enrollment.
- Consolidated CMS-855I/CMS-855R Enrollment Applications (opens in a new tab)
CMS. States that Medicare merged the CMS-855R into the CMS-855I paper enrollment application, that the reassignment data previously collected on the CMS-855R is now captured on the CMS-855I and the CMS-855R will no longer be used to report it, and that reassignments continue to be added, terminated, or changed in the reassignment topic of a PECOS application.
- 42 CFR 424.510 — Requirements for enrolling in the Medicare program (opens in a new tab)
eCFR. Sets what a complete enrollment application must contain, requires submission to the designated Medicare fee-for-service contractor, defines who may sign as an authorized or delegated official, requires agreement to electronic funds transfer on the CMS-588, and carves out the reduced requirements for enrolling solely to order and certify.
- 42 CFR 424.515 — Requirements for reporting changes and updates to, and the periodic revalidation of Medicare enrollment information (opens in a new tab)
eCFR. Establishes the periodic revalidation cycle, provides that CMS contacts each provider or supplier directly when revalidation is due, allows off-cycle revalidation, and routes ambulance and DMEPOS suppliers to their own separate cycles.
- 42 CFR 424.507 — Ordering covered items and services for Medicare beneficiaries (opens in a new tab)
eCFR. Conditions payment for ordered imaging, clinical laboratory services, and DMEPOS items, and for home health and hospice services, on the ordering or certifying practitioner being identified by legal name and NPI and being enrolled in Medicare in an approved status or validly opted out.
- 42 CFR 424.521 — Request for payment by certain provider and supplier types (opens in a new tab)
eCFR. Sets the limited retrospective billing available to a listed set of provider and supplier types for services furnished at the enrolled practice location before the enrollment's effective date.
- Provider Data Profile FAQs for clinicians (opens in a new tab)
DataSpring, formerly CAQH. Describes the provider data profile a clinician attests to once in the CAQH Provider Data Portal and then makes available to the health plans they participate in for credentialing, directory management, and related administrative workflows.