Group Practice vs. Solo Practice Credentialing: What Changes and Why It Matters

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One of the most common misunderstandings we encounter is the assumption that credentialing for a group practice is just "the same thing, but more people." It isn't. The structure of a group practice changes the credentialing model in fundamental ways — the NPI types used, how billing flows, how payer relationships are organized, and what happens when individual providers join or leave the group.

Whether you're a solo practitioner thinking about forming a group, a group practice adding your first employed physician, or an administrator trying to understand why the group practice application looks so much more complicated than what you did for the solo provider two years ago — this guide is for you.

The NPI Foundation: Type 1 vs. Type 2

For a solo practice that is NOT incorporated and bills entirely under the physician's personal NPI and SSN, you may only need a Type 1 NPI. The moment you incorporate (form a PLLC, PC, or corporation) and assign a separate EIN to the practice entity, you need a Type 2 NPI for the organization as well — and you need to enroll that organization with each payer.

Side-by-Side: What's Different Between Solo and Group Credentialing

The Group Credentialing Sequence: Order Matters

This is where we see groups make expensive mistakes. The group practice entity credentialing must come before the individual provider credentialing — not simultaneously, not after. Here's why: payers won't link an individual provider to a group that isn't enrolled yet. If you submit individual applications before the group is enrolled, the payer either holds them pending group enrollment or returns them as incomplete.

The correct sequence:

• Step 1: Obtain group practice EIN from IRS if not already done. Keep the CP-575 letter — you'll need the exact legal name format repeatedly.
• Step 2: Obtain Type 2 NPI for the group practice entity at nppes.cms.hhs.gov
• Step 3: Submit group practice enrollment to each payer (CMS-855B for Medicare, equivalent commercial applications)
• Step 4: Confirm group enrollment approval with each payer before submitting individual provider enrollments
• Step 5: Submit individual provider (CMS-855I for Medicare) with clear reassignment of benefits to the group TIN and NPI

When Providers Leave a Group Practice

This is equally important and equally misunderstood. When a provider departs from a group practice, both the group and the individual provider have credentialing obligations:

• The group must notify all payers of the provider's departure date
• The departing provider must update their CAQH profile to reflect their new or independent practice address
• If the provider is starting an independent practice, they now need to establish their own payer relationships (which means re-credentialing with each payer under their own TIN)
• Billing for services rendered while at the group should continue under the group TIN until the departure date — this is a common audit flag if not handled correctly

We treat provider departures as a credentialing event in its own right, with its own notification checklist. Most practices don't — and it creates billing compliance problems months later.

The Multi-Location Complexity

Group practices with multiple locations add another layer. Some payers credential at the provider level regardless of location (one contract, all locations). Others credential by location — meaning a provider working at your main office and your satellite clinic may technically need to be enrolled at both locations with certain payers. Always verify whether a payer uses provider-level or location-level credentialing for their group panels.