Enrolling in Medicare Part B for CMS's ACCESS Model

What is a Medicare Part B-enrolled provider/supplier? In Medicare terminology, providers typically refer to institutions (like hospitals) and suppliers refer to individuals or entities that furnish Part B medical services (e.g. physician practices, clinics).[1] For our purposes, being Medicare Part B-enrolled means your organization (e.g. your virtual clinic or medical group) is officially registered with Medicare to provide covered services to Medicare beneficiaries and bill Medicare Part B for payment. Essentially, you're on Medicare's list of approved health care entities.

Who is eligible to enroll? Generally, any individual practitioner (physician, nurse practitioner, physician assistant, etc.) or group practice that meets licensing requirements can enroll in Medicare Part B. Digital health startups usually establish a medical group or clinic (with clinicians on staff) to deliver care—that entity can enroll as a "clinic/group practice" supplier. You'll need at least one licensed Medicare-eligible clinician (e.g. an MD/DO or certain non-physician practitioners) associated with your organization to serve as the enrolling provider.

In fact, the ACCESS model requires participants to designate a physician Clinical Director and ensure all clinicians delivering care are individually Medicare-enrolled and affiliated with the organization.[2][3] If you're a pure software company, you'll likely need to partner with or hire medical providers and form a clinical entity to enroll.

Key obligations of Medicare-enrolled entities:

Enrolling in Medicare is like entering a regulated contract with the federal government. Some core commitments include:

• Follow Medicare rules and regulations: You must comply with Medicare coverage policies, coding and billing rules, and all relevant federal laws (like HIPAAThe Health Insurance Portability and Accountability Act (HIPAA) sets national standards for protecting sensitive patient health information. All Medicare providers must comply. for patient privacy and security). You are subject to oversight by CMS and its contractors.
• Maintain state licensure & scope of practice: All clinicians must have valid licenses in the states where patients are treated. Services must be delivered within each provider's scope of practice under state law. CMS requires that participants meet all applicable federal and state requirements.[2]
• Medicare "participating" status: Upon enrollment, you'll choose whether to be a participating providerParticipating providers agree to accept Medicare's approved amount as full payment. Medicare pays 80%, patient/secondary pays 20%. You can't charge above the fee schedule rate. This is highly recommended for ACCESS.. You'll typically sign the Medicare Participating Physician or Supplier Agreement (Form CMS-460) during enrollment.[4]
• Billing under Medicare Part B: Once enrolled, you can bill Medicare for covered services under the Physician Fee Schedule (PFS). Medicare will issue your organization a PTANPTAN (Provider Transaction Access Number): A unique identifier assigned by your MAC for billing purposes. Different from your NPI—you need both to submit Medicare claims. linked to your National Provider Identifier (NPI).
• Update information and revalidate: Changes in ownership, practice location, or legal status must be reported within 30 days; other changes (phone number, personnel) within 90 days.[5] Medicare requires revalidation typically every 5 years. Failure to update or respond to revalidation can result in billing privileges being revoked.[6]
• Program integrity and screening: You and your key owners/managers will undergo background screening. Any individual with certain felonies or exclusions from federal health programs can cause denial. You must also disclose any adverse legal actions on your application.
• Patient access: Unlike some value-based programs, Medicare enrollment does not obligate you to take every Medicare patient. You retain control over your services. However, you cannot discriminate based on race, religion, or health status. ACCESS participants will be listed on a public CMS directory.[7][8]

Why Part B enrollment is required for ACCESS:

The ACCESS model is a Medicare initiative that pays for technology-enabled chronic care. CMS explicitly states that to participate, an organization "must be enrolled in Medicare Part B as [a] provider or supplier".[9] This is non-negotiable—CMS will not waive the enrollment requirement even for innovative startups.[10]

Enrolling in Part B establishes the necessary billing framework (you'll use your Medicare enrollment to submit the model's G-codesG-codes are HCPCS codes used for procedures not described by CPT codes. ACCESS will use model-specific G-codes to process outcome-aligned payments through the Medicare claims system. for payment). It also subjects you to Medicare's oversight, which gives CMS confidence in your reliability. In short, Part B enrollment is the gateway to receiving Medicare payments, whether traditional fee-for-service or the new ACCESS payments.

Medicare provider enrollment can seem daunting, but CMS's online system PECOS (Provider Enrollment Chain & Ownership System) streamlines the process. PECOS lets you submit your application electronically and is faster than paper (often 2–4 weeks faster).[11][12] Below, we walk through the enrollment process for a virtual-first group practice.

2.1 Prepare Required Information and Documents

Before logging into PECOS, gather all necessary data and documents. Missing pieces are a leading cause of delays or denials.

2.2 Create an I&A (Identity & Access) Account

PECOS requires CMS login credentials via the Identity & Access Management System. Go to pecos.cms.hhs.gov and select "New User? Register Here." Each person who needs to work on the application must have their own account—no sharing credentials.[20][21][22]

2.3 Log In to PECOS and Start a New Enrollment

Once in PECOS, you'll link your I&A account to your organization's EIN. Then navigate to "My Enrollments" and create a new application. Select "Clinic/Group Practice" as your provider type—PECOS will automatically select the correct form (CMS-855B).[24][25]

2.4–2.7 Complete the Application

PECOS will guide you through sections covering organization information, ownership, practitioner reassignments, and document uploads. The key steps:

2.8 After Submission: Approval and Next Steps

Your regional MACMedicare Administrative Contractor (MAC): Regional contractors that process Medicare claims and handle provider enrollment. Your practice location determines which MAC you work with. (Medicare Administrative Contractor) will process your application. Processing typically takes 45–90 days.[29] They may contact you for additional information—respond promptly to avoid delays.[101]

Upon approval, the MAC sends a letter with your PTAN (Provider Transaction Access Number) and effective date. Keep this letter—you'll need it for the ACCESS application. Congratulations—you're enrolled! Your digital health company is now a Medicare Part B supplier, eligible to sign a participation agreement for the ACCESS model.[31]

Medicare Part B primarily pays for services under the Physician Fee Schedule (PFS)—essentially a catalog of services and payment rates. Here's what a Part B supplier should know:

• CPT/HCPCS Codes: Every billable service has a code. Under PFS, you submit claims with these codes and Medicare pays the pre-set amount (adjusted by region).
• Supplier billing under PFS: You'll use your clinicians' NPIs and your group NPI/TIN to submit claims. Payment is typically 80% from Medicare (patients have 20% coinsurance). You cannot arbitrarily set prices—it's governed by the PFS.
• Updates and geographic variation: The PFS is updated annually. Payment rates vary by location due to Geographic Practice Cost Indices (GPCIs).

Why PFS matters for ACCESS:

ACCESS introduces Outcome-Aligned Payments (OAPs)—fixed, periodic payments tied to patient outcomes rather than specific services.[32] ACCESS "replaces traditional fee-for-service billing with fixed recurring payments" for participants. However, these payments are implemented through the existing claims system using special HCPCS G-codes.

While an ACCESS patient's chronic care is covered by the model payment, you generally "may not bill any Medicare FFS claims" for those patients' aligned condition during the ACCESS care period.[33] Understanding these boundaries prevents double billing.

Coordinating providers: ACCESS allows patients to keep seeing their primary care providers. Those outside providers bill Medicare normally. ACCESS introduces a small co-management fee (~$100/year per patient) payable to patients' primary care doctors for collaborating.[34][35]

Digital health startups often hear conflicting information. Let's clear up common misunderstandings:

In short, digital health companies can succeed in Medicare—you just need to navigate the enrollment process and follow the rules.

Enrolling in Medicare was the first big step. Now, as a Part B provider aiming to join ACCESS, your organization takes on a set of ongoing responsibilities. Think of this as your operational checklist post-enrollment.

5.1 Regulatory Compliance and Clinical Standards

Continue operating as a compliant Medicare supplier. Key areas:

• Privacy (HIPAA): Ensure all patient data handling meets HIPAA requirements. Have a Notice of Privacy Practices, train staff, use secure systems for PHI.
• Quality and safety: CMS will monitor participant outcomes. Establish internal quality metrics, hold clinical team meetings, conduct chart reviews. If using digital therapeutics, ensure compliance with any FDA requirements.[45]
• Fraud and abuse compliance: Establish policies to avoid fraud. Train staff on Anti-Kickback Statute rules. Be mindful of Stark Law if physician owners refer patients. Keep thorough documentation.

5.2 Delivering Care Under the ACCESS Model

ACCESS is outcomes-driven and offers flexibility in how you deliver care:

• Care model and scope: Choose clinical tracks (Cardio-metabolic, MSK pain, Depression/Anxiety, etc.).[46] Manage each patient's qualifying condition for a 12-month care period using virtual visits, remote monitoring, coaching, digital therapeutics—whatever improves outcomes.[47][48]
• Patient onboarding and consent: Obtain written consent from beneficiaries. Make onboarding user-friendly but thorough.
• Coordination with other providers: Share care plans and periodic updates with patients' PCPs.[50][51] Use secure electronic methods (Direct messaging, HIE portals, FHIR-based exchange). Document coordination attempts.
• Patient accessibility: Offer multiple touchpoints—nurse or coach for questions, app for monitoring, periodic virtual visits. Consider 24/7 support for urgent issues.

5.3 Billing and Payment Infrastructure

Even though ACCESS isn't standard FFS, you need robust billing infrastructure:

• MAC relationship: All claims (including G-codes) go to your regional MAC.[60] Set up EDI through a clearinghouse.
• G-code billing: ACCESS uses model-specific G-codes submitted like regular claims.[63][60] You'll submit monthly claims for each patient. Expect additional guidance on codes in 2026.
• Partial withholds: CMS mentioned outcome-based adjustments.[67][68] You may get 70% monthly with 30% held until outcome verification. Track withholds carefully.
• No patient billing: During active care, don't bill patients for co-pays—OAPs have no beneficiary cost-sharing.[69][51]

5.4 Outcomes Reporting via FHIR API

ACCESS requires reporting clinical outcomes via FHIR API:[70][71][72][73]

• Measurement types: Patient-Reported Outcome Measures (PROMs), clinical data (blood pressure, A1C), and potentially composite scores.
• FHIR resources: CMS may use FHIR Observation resources for vitals, QuestionnaireResponse for PROMs. Ensure your team understands FHIR basics.
• Other APIs: Eligibility API to confirm beneficiary status, Alignment API to enroll patients, Claims data API (BB/BCDA) for care coordination.[74][75][76]
• Integrity: Submit actual measured values. Be prepared for audits—misreporting outcomes could be a false claim.

5.5 Ongoing Admin

• Revalidation: Update PECOS for changes. Respond to revalidation requests (every 5 years).[6]
• Communication: Subscribe to MAC email updates and ACCESS listserv. Attend CMS webinars.
• Audits: Anticipate program integrity audits of records, enrollment compliance, and patient outreach practices.

Enrolling in Medicare and participating in ACCESS is an investment. Here's what to budget:

Enrollment Costs

No application fee for physician practices.[26] Incidental costs include NPI registration (free), possibly notarizing documents. If using a credentialing consultant, that varies. Expect 10–20 hours of staff time for careful initial enrollment.

Staffing and Training

• Billing/coding expertise: A medical biller or RCM service familiar with Medicare (~$500–$1,000/month for small volume, or ~5% of collections).
• Compliance: Assign a compliance officer. Budget for periodic healthcare attorney consultations (~$10k–$20k/year at startup size).
• IT integration: FHIR API development, data reporting pipelines. Could range from minimal (existing tools) to tens of thousands (custom build).
• Clinical staffing: At minimum, one physician Medical Director[27] plus NP/PA or RN care managers. Plan your care team ratio vs. expected payments.

Infrastructure and Tools

• EHR/care management: Low-cost options exist. Ensure you can produce CMS claims files.
• API systems: Budget for FHIR connectivity—DIY or subscribe to middleware services.
• Devices: If providing RPM devices (BP cuffs, glucose monitors), factor in hardware and shipping costs.

Ongoing Administrative Overhead

Plan for monthly claims submission, quarterly outcome reports, patient coordination documentation, revalidation every 5 years, and audits. Many startups find that after the initial learning curve, Medicare operations become routine.

With Medicare enrollment complete, you're ready to apply for the ACCESS Model:

• Request for Applications (RFA): CMS has released the ACCESS Model RFA.[82] Initial applications are due by April 1, 2026 for the first cohort.[83] The model accepts new participants through 2033 on a rolling basis.[78]
• Medicare enrollment proof: The application requires your Medicare CCN/PTAN. "Applicants will need to enroll in Medicare Part B prior to executing a participation agreement."[10]
• Interest form: CMS has an Interest Form on their site[84][85]—fill it out to get on their email list.
• Participation Agreement: If approved, you'll sign a formal contract with CMS governing model participation.

Resource Library

Let's conclude with pitfalls to avoid so your enrollment and model launch go smoothly: