Medicare Provider Enrollment Applications: Forms and Requirements for 2026

Choosing the correct Medicare provider enrollment application depends on whether you are enrolling an individual practitioner, a group practice, or another healthcare supplier. CMS-855I is used for individual practitioners and reassignment, while CMS-855B is used for clinics, group practices, and certain other suppliers. Additional applications may be necessary for institutional enrollment, electronic payments, or Medicare participation.

Most Medicare enrollment applications can be completed electronically through the Provider Enrollment, Chain, and Ownership System (PECOS). Understanding which application to use helps practices avoid enrollment delays, billing complications, and payment interruptions.

For healthcare organizations hiring physicians, nurse practitioners, or other eligible professionals, accurate enrollment is an essential part of revenue cycle management. Every missing document, incorrect application, or unapproved billing relationship can delay Medicare reimbursement.

What Is the Medicare Provider Enrollment Process?

Medicare provider enrollment is the process through which the Centers for Medicare & Medicaid Services (CMS) verifies that healthcare professionals and organizations meet the requirements to obtain or maintain Medicare billing privileges.

During enrollment, Medicare verifies information such as:

• Professional licenses and qualifications
• National Provider Identifiers (NPIs)
• Legal business names and Tax Identification Numbers (TINs)
• Practice locations and contact information
• Ownership and managing control information
• Required supporting documentation
• Banking information for Medicare payments
• Applicable federal enrollment requirements

Most healthcare providers complete Medicare enrollment through PECOS, CMS’s online Medicare enrollment management system.

PECOS allows eligible providers and suppliers to submit enrollment applications, update existing records, upload supporting documentation, manage reassignment relationships, and monitor application activity.

Although PECOS provides the electronic enrollment process, Medicare applications are still identified by their corresponding CMS form numbers.

Related reading: 2026 Medicare Provider Enrollment Guide.

Which Medicare Provider Enrollment Application Do You Need?

The correct Medicare enrollment application depends on the type of provider or organization and the purpose of the enrollment. Individual practitioners, medical groups, institutional providers, and certain suppliers use different application forms.

For example, a physician enrolling individually generally uses CMS-855I, while a medical group enrolling as a Medicare supplier generally uses CMS-855B. A practitioner joining an existing group may also need to establish a reassignment relationship so the group can receive payment for covered professional services.

Some enrollment situations require more than one application or enrollment transaction. A new group practice enrolling its first physician may need organizational enrollment, individual practitioner enrollment, reassignment, and electronic payment information.

Understanding how these requirements work together helps practice managers select the correct enrollment path and avoid unnecessary delays.

CMS-855I: Medicare Enrollment for Individual Practitioners

CMS-855I is the Medicare enrollment application used by physicians and eligible nonphysician practitioners to enroll, revalidate, or update their Medicare enrollment information.

Eligible professionals commonly using CMS-855I include:

• Physicians
• Nurse practitioners
• Physician assistants
• Clinical psychologists
• Clinical social workers
• Physical therapists
• Occupational therapists
• Other eligible healthcare practitioners

The application establishes the individual practitioner’s Medicare enrollment record and collects information required to evaluate eligibility for Medicare billing privileges.

What Information Does CMS-855I Require?

Depending on the practitioner’s enrollment circumstances, CMS-855I may require:

• Legal name and identifying information
• Individual Type 1 NPI
• Professional license information
• Specialty and professional qualifications
• Practice locations and contact details
• Reportable adverse legal actions
• Reassignment information, when applicable
• Required certifications and signatures

Practices should verify that the application information matches official professional licensing records and the National Plan and Provider Enumeration System (NPPES).

Inconsistent names, addresses, license information, or identification numbers can result in requests for additional documentation.

Important: Individual Medicare enrollment does not automatically establish a reassignment relationship with a medical group. The applicable reassignment must also be reported and approved.

Official resource: CMS-855I Medicare Enrollment Application.

Related reading: Provider Credentialing Process.

CMS-855B: Medicare Enrollment for Group Practices and Organizations

CMS-855B is the Medicare enrollment application for clinics, group practices, and certain other suppliers. It is used to establish and maintain the Medicare enrollment of eligible organizations.

Common examples include:

• Physician group practices
• Multispecialty medical groups
• Certain independent therapy practices
• Certain diagnostic and testing suppliers
• Eligible healthcare clinics and organizations
• Other suppliers specifically covered by CMS-855B

Not every healthcare organization uses CMS-855B. Hospitals and certain institutional providers generally use CMS-855A, while durable medical equipment, prosthetics, orthotics, and supplies (DMEPOS) suppliers generally use CMS-855S.

What Information Does CMS-855B Require?

CMS-855B collects organizational enrollment information, including:

• Legal business name and TIN
• Organizational Type 2 NPI
• Business structure and ownership details
• Managing employees and control information
• Practice locations
• Contact information
• Applicable supplier details
• Authorized and delegated officials
• Required supporting documentation

The information must accurately reflect the organization’s legal and operational structure.

What Changed With CMS-855B in 2026?

CMS revised the CMS-855B application in 2026. Starting August 3, 2026, the revised CMS-855B became required for applicable paper submissions.

Important changes include:

• Allowing groups to establish, terminate, or change reassignment relationships
• Removing the former physician assistant employer relationship reporting requirement
• Adding an enrollment reason for certain organizations enrolling solely to participate in Medicaid or another healthcare program
• Expanding practice location categories to address certain administrative and telehealth arrangements

These changes are particularly important for group practices that frequently add or remove healthcare professionals.

Practices submitting paper enrollment applications should use the current CMS-issued form rather than relying on previously downloaded versions.

Official resource: CMS-855B Medicare Enrollment Application.

How Do You Reassign Medicare Benefits to a Group Practice?

When a physician, nurse practitioner, or another eligible professional joins a Medicare-enrolled group practice, the group generally needs an approved reassignment relationship to receive Medicare payment for the practitioner’s covered professional services.

Medicare reassignment is handled through PECOS or the applicable sections of CMS-855I. The separate CMS-855R application was discontinued effective October 31, 2023.

Before this change, providers used CMS-855R to establish, modify, or terminate reassignment relationships. CMS consolidated those requirements into CMS-855I to simplify the enrollment process.

The revised CMS-855B also permits enrolled groups to report certain reassignment changes.

How Can a Medical Practice Add a Provider’s Reassignment?

1. Verify individual Medicare enrollment. Confirm that the practitioner is enrolled or complete the applicable individual enrollment process.
2. Verify group enrollment. Confirm that the receiving organization has the appropriate active Medicare enrollment.
3. Submit reassignment information. Use PECOS or the applicable current CMS enrollment application and reassignment sections.
4. Provide required signatures. Ensure the practitioner and authorized group representatives complete the required certifications.
5. Monitor the application. Respond promptly to requests from the Medicare Administrative Contractor.
6. Verify approval. Confirm the reassignment relationship, associated enrollment details, and applicable effective dates before billing.

Medical practices should not assume that a provider’s existing Medicare enrollment automatically authorizes billing under a new employer’s TIN.

The billing relationship must be appropriately established, and the practice should verify that its Medicare enrollment records support the services being billed.

Official resource: CMS Guidance on Consolidated CMS-855I and CMS-855R Applications.

CMS-588: Setting Up Medicare Electronic Payments

CMS-588 is the Electronic Funds Transfer (EFT) Authorization Agreement used to establish or update banking information for Medicare payments.

Medicare generally requires providers and suppliers to receive payments electronically, subject to applicable requirements and exceptions.

When completing CMS-588, providers may need to supply:

• Legal provider or supplier information
• Applicable NPI and TIN
• Financial institution information
• Bank routing number
• Account number and account type
• Supporting banking documentation
• Required authorized signatures

Supporting documentation may include a voided check or an acceptable financial institution letter, depending on the applicable enrollment instructions.

Incorrect banking information, inconsistent legal names, or missing documents can delay EFT setup and Medicare reimbursements.

Practices should verify that the financial information matches the appropriate Medicare enrollment records before submission.

Official resource: CMS Enrollment Applications and EFT Resources.

CMS-460: Choosing Medicare Participating Status

Medicare enrollment and Medicare participation are related but different concepts.

CMS-460 is the Medicare Participating Physician or Supplier Agreement used by eligible physicians and suppliers who elect participating status.

A participating provider agrees to accept assignment for covered Medicare services, meaning the provider accepts the Medicare-approved amount as payment in full, apart from applicable deductible and coinsurance amounts.

Participating physicians and suppliers generally receive Medicare Physician Fee Schedule payments at the participating rate.

Nonparticipating physicians and suppliers who remain enrolled in Medicare are generally subject to a lower nonparticipating fee schedule amount, along with additional assignment and billing rules.

Not every Medicare-enrolled provider or supplier follows the same participation election process. Practices should confirm the applicable rules before submitting CMS-460.

Practices should also understand that participation status and opting out of Medicare are separate matters with different requirements.

For applicable new enrollment and annual participation elections, providers should follow CMS and their Medicare Administrative Contractor’s current instructions and deadlines.

Other Medicare Provider Enrollment Applications to Know

Although CMS-855I and CMS-855B cover many physician and group practice enrollment situations, other CMS applications apply to different provider and supplier types.

CMS-855A: Institutional Providers

CMS-855A is used by institutional providers, including hospitals and other eligible institutional healthcare organizations. The specific enrollment requirements depend on the provider type.

CMS-855O: Ordering and Certifying Professionals

CMS-855O is used by eligible physicians and other professionals enrolling solely for applicable ordering or certifying purposes rather than submitting claims for their own covered professional services.

CMS-855S: DMEPOS Suppliers

CMS-855S applies to suppliers enrolling to furnish Medicare-covered durable medical equipment, prosthetics, orthotics, and supplies.

DMEPOS suppliers are subject to additional enrollment and supplier requirements.

Providers should always confirm the correct enrollment category rather than assuming that a physician group application applies to every healthcare business.

Medicare Provider Enrollment Applications at a Glance

The following table summarizes commonly used Medicare enrollment forms and their primary purposes.

CMS Form	Primary Purpose	Typical Applicants
CMS-855I	Individual practitioner enrollment and reassignment	Physicians and eligible nonphysician practitioners
CMS-855B	Group and certain supplier enrollment	Medical groups, clinics, and eligible suppliers
CMS-855A	Institutional provider enrollment	Hospitals and other qualifying institutional providers
CMS-855O	Enrollment solely for ordering or certifying	Eligible ordering and certifying professionals
CMS-855S	DMEPOS supplier enrollment	Eligible DMEPOS suppliers
CMS-588	Electronic Funds Transfer authorization	Providers and suppliers establishing Medicare payment accounts
CMS-460	Medicare participation agreement	Eligible physicians and suppliers electing participating status

Important: CMS-855R is no longer a separate enrollment application. Reassignment information is now handled through the applicable current enrollment process.

The specific forms required depend on the provider type, enrollment situation, and information already on file with Medicare.

Official reference: CMS Medicare Enrollment Applications.

How Does the Medicare Provider Enrollment Application Process Work?

Consider a growing multispecialty clinic that hires a nurse practitioner named Sarah.

The clinic wants Sarah to begin treating Medicare patients while ensuring that Medicare claims can be submitted correctly under the practice’s billing arrangements.

Step 1: Verify Sarah’s Individual Medicare Enrollment

If Sarah has never enrolled in Medicare, she must complete the applicable individual enrollment process through PECOS or CMS-855I.

If she is already enrolled, the practice should verify her current Medicare enrollment information and determine which updates are required.

Step 2: Establish the Reassignment Relationship

Because the clinic will bill Medicare for Sarah’s professional services, an appropriate reassignment relationship must be established.

This is handled through PECOS or the applicable CMS-855I process rather than a separate CMS-855R application.

The revised CMS-855B also provides groups with options for reporting reassignment changes.

Step 3: Confirm the Clinic’s Organizational Enrollment

The clinic has already completed its organizational enrollment under CMS-855B.

If the organization’s enrollment information remains current and no additional organizational changes are required, it generally does not need a completely new group enrollment simply because Sarah has joined.

Step 4: Verify Medicare Payment Information

The clinic should confirm that its EFT information and other relevant enrollment records remain accurate.

If its existing Medicare payment arrangement is valid and unchanged, a new CMS-588 may not be necessary solely because another practitioner joins the group.

Step 5: Confirm Approval and Billing Readiness

The practice should monitor the application, respond to Medicare Administrative Contractor requests, and verify the enrollment and reassignment information.

Before submitting claims, the clinic should confirm the applicable enrollment effective dates, billing relationships, and other Medicare billing requirements.

This example demonstrates how individual enrollment, organizational enrollment, and reassignment work together during provider onboarding.

What Are the Most Common Medicare Enrollment Application Mistakes?

Many Medicare enrollment delays result from incomplete applications, inconsistent information, or missing supporting documentation.

Common mistakes include:

• Incorrect legal names: Business or provider names that do not match official records.
• NPI inconsistencies: Using incorrect or outdated NPPES information.
• Wrong application type: Selecting an individual, organizational, institutional, or supplier enrollment form that does not match the applicant.
• Outdated paper forms: Submitting a previous version instead of the current CMS application.
• Missing ownership information: Failing to disclose required owners or managing individuals.
• Incorrect practice locations: Reporting outdated, incomplete, or inconsistent addresses.
• Incomplete reassignment information: Assuming that individual enrollment automatically allows a new group to receive payments.
• Banking discrepancies: Providing EFT information that does not satisfy Medicare’s documentation requirements.
• Missing signatures: Failing to obtain required practitioner or authorized official certifications.
• Delayed responses: Not responding promptly to requests from the Medicare Administrative Contractor.

Healthcare organizations should review enrollment information against their official business, licensing, and NPPES records before submission.

A standardized review process helps identify discrepancies early and reduces avoidable administrative delays.

Why Should Healthcare Practices Use PECOS?

PECOS is CMS’s online Medicare enrollment management system, allowing eligible providers and suppliers to submit applications, update enrollment records, and upload supporting documents electronically.

PECOS can offer several advantages over paper enrollment.

• Electronic enrollment application submission
• Online updates to existing Medicare enrollment information
• Electronic document uploads
• Reassignment management
• Application status monitoring
• Electronic signatures where supported
• Reduced reliance on mailed documentation

Electronic submissions can be processed more efficiently than paper applications, although processing times depend on the application type, completeness, and required reviews.

PECOS does not eliminate Medicare enrollment requirements or guarantee approval.

Providers must still submit accurate information, complete required certifications, and respond to requests from their Medicare Administrative Contractor.

Related reading: PECOS Provider Enrollment for Healthcare Practices.

What Does a Medicare Administrative Contractor Do?

Medicare Administrative Contractors (MACs) process Medicare enrollment applications for providers and suppliers within their assigned jurisdictions.

MAC responsibilities include reviewing applications, verifying submitted information, requesting missing documentation, and making enrollment determinations under CMS requirements.

Examples of Medicare Administrative Contractors include Novitas Solutions, Palmetto GBA, Noridian Healthcare Solutions, and WPS Government Health Administrators.

Practices should identify the MAC responsible for their applicable provider type and geographic jurisdiction.

When a MAC requests additional information, organizations should respond within the specified deadline to prevent unnecessary processing delays or adverse application actions.

Official resource: CMS Medicare Administrative Contractors.

How Can Practices Build a Better Medicare Enrollment Workflow?

A consistent Medicare enrollment workflow helps healthcare organizations manage applications, documentation, reassignment, and billing readiness more effectively.

Recommended practices include:

1. Start early. Begin the enrollment process as soon as the practice has the information necessary to proceed.
2. Verify identifiers. Confirm NPIs, TINs, legal names, and practice locations.
3. Maintain a documentation checklist. Organize professional licenses, business records, ownership information, and supporting documents.
4. Select the correct application. Determine whether CMS-855I, CMS-855B, or another form applies.
5. Coordinate reassignment. Confirm which organizations will receive Medicare payments for the practitioner’s covered services.
6. Verify EFT information. Make sure required payment information is complete and accurate.
7. Track submissions. Monitor PECOS activity and MAC correspondence.
8. Confirm enrollment effective dates. Review approval details before deciding which services can be billed.
9. Maintain current records. Report required changes and complete revalidation when due.

Practices should also coordinate Medicare enrollment with commercial payer credentialing, staffing decisions, and revenue cycle operations.

Related reading: Provider Credentialing Timeline: What Every Practice Should Know.

Frequently Asked Questions About Medicare Provider Enrollment Applications

Which Medicare enrollment application does a nurse practitioner need?

A nurse practitioner enrolling individually in Medicare generally uses CMS-855I or the corresponding PECOS enrollment process. If the nurse practitioner will bill through a group practice, an appropriate reassignment relationship may also be required.

Is CMS-855R still used for Medicare reassignment?

No. CMS discontinued the separate CMS-855R application effective October 31, 2023. Reassignment information is now handled through CMS-855I or PECOS. The revised CMS-855B also allows groups to report certain reassignment changes.

What is the difference between CMS-855I and CMS-855B?

CMS-855I is used for individual physicians and eligible nonphysician practitioners. CMS-855B is used for clinics, group practices, and certain other Medicare suppliers. Some group practice arrangements require both individual and organizational enrollment records.

Can a provider bill Medicare without reassignment?

An individually enrolled practitioner may be able to bill under an applicable individual Medicare enrollment arrangement. However, when a group intends to receive Medicare payment for the practitioner’s professional services, an appropriate reassignment or other permitted payment arrangement must be established.

Can Medicare enrollment applications be submitted online?

Yes. Most Medicare enrollment applications can be completed through PECOS. The system supports electronic submission, enrollment updates, supporting documents, and applicable reassignment transactions.

How long does Medicare provider enrollment take?

Medicare enrollment processing times vary by application type, Medicare Administrative Contractor, application completeness, and whether additional review or documentation is necessary. Practices should begin the process early and monitor application activity rather than assuming a guaranteed approval date.

Does Medicare enrollment automatically credential a provider with Medicare Advantage plans?

No. Original Medicare enrollment and Medicare Advantage plan network participation are separate processes. Providers seeking in-network status with Medicare Advantage organizations generally must satisfy the applicable health plan’s contracting and credentialing requirements.

Does a medical group need a new CMS-855B every time it hires a provider?

Not necessarily. An existing Medicare-enrolled group generally does not need an entirely new organizational enrollment solely because it hires another practitioner. However, required reassignment and enrollment updates must still be completed.

Medicare Enrollment Supports Long-Term Revenue Growth

Completing the correct Medicare provider enrollment application involves more than submitting paperwork. Accurate enrollment supports proper billing relationships, compliant claims submission, and timely reimbursement.

Whether a healthcare practice is hiring its first physician, adding nurse practitioners, opening another location, or expanding into a multispecialty organization, an organized enrollment process helps reduce administrative obstacles.

Understanding CMS-855I, CMS-855B, PECOS, reassignment requirements, and Medicare payment setup allows practice managers to make better operational decisions.

At eClinicAssist, we help healthcare organizations navigate Medicare enrollment, PECOS submissions, provider credentialing, payer enrollment, and related administrative requirements.

Our team assists practices with application preparation, documentation review, enrollment coordination, and follow-up so providers can move toward billing readiness with greater confidence.

Need assistance with Medicare provider enrollment? Contact eClinicAssist to discuss your practice’s enrollment requirements and how our credentialing team can help.