By specialty
Physician Assistant Credentialing Services
Physician assistants enrol in Medicare individually on the CMS-855I and, since 2022, may bill Medicare directly and reassign benefits like other practitioners rather than only through an employer. PA services are paid at the standard non-physician practitioner percentage of the fee schedule unless the incident-to conditions are met in full, and those conditions are audited.
Physician assistant credentialing is done badly more often than almost any other kind, and the reason is a piece of billing mechanics rather than any complexity in the credentialing itself. Because a PA’s claims can go out under a supervising physician’s number, practices conclude the PA does not need to be enrolled and credentialed in their own right. That conclusion is wrong, it is common, and its consequences arrive years later in the form of a records request.
Enrolment is not optional, whoever’s number is on the claim
State it plainly: a physician assistant must be individually enrolled with Medicare and credentialed with the payers, regardless of how their services are billed.
A PA who has been practising for two years with every claim submitted under a physician’s number is, to the payers, an unenrolled and uncredentialed clinician. Nothing about the billing arrangement changes that. And the arrangement it depends on — incident-to billing — has conditions, so a review that examines those conditions and finds them unmet will look next at whether the rendering clinician was enrolled and participating. At that point the practice is answering two questions instead of one.
The correct posture is boring and cheap: enrol and credential every PA on hire, exactly as you would a physician, and then decide separately how each service should be billed.
What actually changed in 2022
Before 2022, Medicare payment for PA services could only be made to the PA’s employer. PAs could not bill directly and could not reassign their benefits the way nurse practitioners and clinical nurse specialists could.
That changed. Physician assistants may now bill Medicare directly and reassign benefits like other practitioners. The structural consequences are real:
- PA-owned and PA-partnered practice structures became possible in ways they were not.
- Reassignment is straightforward where a PA works for more than one entity, rather than being constrained by an employment-payment rule.
- Enrolment setups built on the old constraint are frequently more restrictive than they need to be, without anyone having revisited why.
Practices operating on pre-2022 assumptions are not usually doing anything wrong. They are usually carrying a structure designed around a limitation that no longer applies, and paying for it in flexibility.
Incident-to is all of the conditions, not most
Services meeting the incident-to requirements are paid at the full physician rate; services that do not are correctly billed under the PA at the non-physician practitioner percentage of the fee schedule. That differential is why the arrangement is attractive, and why it is the most audited thing in outpatient billing.
The conditions, in full:
- Established patient. The physician personally performed the initial service for the problem and established the plan of care.
- Established problem, following that plan. A new problem presented at the visit takes the service outside incident-to entirely, even mid-encounter.
- Direct supervision. The physician is present in the office suite and immediately available. Not in the building next door, not reachable by phone.
- The relationship requirement, with the PA employed or otherwise qualifying.
- Ongoing physician involvement in the course of care.
The failure mode is never a decision to bill improperly. It is a Tuesday when the physician is at the hospital, or a patient who mentions something new, or a plan of care that drifted over eighteen months into something the physician never established. The practices that survive review are the ones whose schedule makes supervision verifiable and whose documentation shows the plan, not the ones whose billing policy says the right thing.
Split visits are a different rule entirely
In a facility setting, where a physician and a PA from the same group both contribute to a single visit on the same day, the visit is billed by the practitioner who performed the substantive portion — a definition CMS has been tightening over time.
Incident-to does not apply in the hospital setting at all. Practices that carry office rules into facility billing produce an error pattern rather than an isolated mistake, and patterns are what prompt review.
Any group whose PAs work across both settings needs two distinct billing rules and staff who know which one they are in. That is a training issue with a compliance consequence, and it is worth addressing at onboarding while somebody is already reading the file.
Payers treat PAs inconsistently, and it changes the work
Commercial payers do not agree on how to handle PAs. Some panel them individually, issue their own participation and expect a full application. Others do not credential PAs at all, covering them under the supervising physician or the group’s contract with the PA rostered rather than paneled.
The distinction determines where the effort goes. Individual paneling means applications, CAQH and a ninety-to-one-hundred-and-fifty-day cycle. Group coverage means roster linkage, effective dates, and written confirmation that the payer’s system recognises the clinician against the group’s tax ID.
Both fail identically if nobody checks. The PA sees patients, the claims go out, and denials arrive weeks later naming a rendering provider the payer does not associate with your group — by which point the filing window is consuming itself.
Establishing the model payer by payer before the PA starts costs a day. Not establishing it costs a quarter.
Delegation agreements are operational documents in Texas
Texas physician assistants practise under physician delegation, with a written agreement covering the delegated services and prescriptive authority where the PA prescribes.
Payers routinely request the agreement in the credentialing packet rather than accepting an attestation that one exists. That makes it an operational document with two consequences most practices under-manage:
- It has to name the correct supervising physician for each location. A multi-site practice with a single agreement naming one physician does not match its own operations.
- Changes are payer notifications. A supervising physician leaving, a new site opening, a change in delegated scope — each has a timeline attached, and none of them updates itself.
A PA whose credentialing file names a supervising physician who left eighteen months ago is a discrepancy sitting in wait for the next recredentialing cycle, and it will be found.
The pattern this page exists to prevent
A practice hires a PA. The PA is excellent and immediately busy. Billing goes out incident-to because that is what the practice has always done. Nobody enrols the PA individually, because on this billing model it seems unnecessary. Two years later a payer requests records for a sample of visits, asks where the supervising physician was on particular dates, and asks whether the rendering clinician was enrolled.
Every part of that is preventable at hire, for a fraction of what it costs to answer afterwards. Enrol and credential the PA. Establish per payer whether they panel individually or cover under the group. Confirm linkage in writing with effective dates. Then decide how each service is billed, with a schedule that makes the answer defensible.
Texas specifics
Licensure is verified against the Texas board record, and the delegation and prescriptive authority arrangement is verified alongside it rather than inferred. Payers pull directly from the board, so a name or address change that has not reached it surfaces as a verification failure downstream.
Texas Medicaid enrolment runs through TMHP’s PEMS portal for the individual PA and for the group, and it closes before any Medicaid managed care organisation will begin. For rural and paediatric practices — where PAs carry a large share of the clinical load — that is a substantial part of the payer mix sitting behind a state enrolment.
How we work a physician assistant file
We enrol and credential the PA as a clinician in their own right, whatever the intended billing model, because that is the foundation everything else stands on. CAQH built once and maintained. The delegation agreement collected, current, and matched to the locations and physicians it actually covers. Payer-by-payer confirmation of whether the PA is paneled or rostered. And linkage tracked to written effective dates, because in a group practice that confirmation, not the approval letter, is what makes the work payable.
What a payer actually verifies
Every item below is pulled from its primary source, not taken on your word. A gap in any one of them stalls the file without a rejection letter.
| What they check | Where it comes from |
|---|---|
| Texas physician assistant licence, current and unencumbered | Texas Physician Assistant Board licence verification |
| National certification as a physician assistant, current | The national certifying body's public verification record |
| Accredited physician assistant programme completion | Programme registrar or the payer's contracted verification organisation |
| The prescriptive authority and delegation agreement with the supervising physician | The signed agreement itself, plus the Texas board record where registration applies |
| DEA registration, where controlled substances are prescribed | DEA registration verification |
| Malpractice coverage, limits, and claims history | Certificate of insurance from the carrier |
| Adverse action and licensure history | National Practitioner Data Bank |
| Exclusion and sanction screening | OIG LEIE, SAM.gov, and the Texas OIG exclusion list |
| Every practice location and the supervising physician at each | Your attestation, matched against the group's enrolment record and payer roster |
What the timeline actually looks like
| Step | Typical | What decides it |
|---|---|---|
| CAQH profile built and attested | 1–2 weeks | Read by the commercial payers. Work history gaps and the delegation agreement are the two items that usually delay it. |
| Medicare enrolment — CMS-855I and CMS-855R | 45–90 days | Novitas Solutions for Texas. Individual enrolment plus reassignment to the practice that bills. |
| Commercial panel credentialing | 90–150 days | Varies sharply by payer — some panel PAs individually, others cover them under the supervising physician or the group contract. |
| Texas Medicaid — TMHP PEMS, then MCO contracts | 45–90 days, then 30–90 each | Individual and group linkage. Paediatric and rural practices carry heavy Medicaid volume. |
| Group linkage confirmed with effective dates | 2–6 weeks after credentialing approval | The milestone that actually makes claims payable. The approval letter is not it. |
| Adding a new practice location or supervising physician | 30–60 days | Payer records, the delegation arrangement and the group enrolment all have to agree, and they update on different clocks. |
The services that matter most here
Insurance credentialing
Individual panel participation where payers offer it, and correct linkage where they cover PAs under the group instead.
How it works →Medicare & Medicaid enrollment
The CMS-855I, reassignment, and TMHP PEMS — required whether or not the PA's claims go out under their own number.
How it works →CAQH setup & maintenance
The commercial panels read the file from CAQH, and a lapsed attestation stalls an application silently.
How it works →Medical billing & RCM
Incident-to conditions and split visit rules decide the rate, and they are documentation questions before they are billing ones.
How it works →Pricing is quoted per practice — payers, providers, and states drive it — and your exact number goes in writing before you commit.How pricing works →
Common questions
If our PA always bills under the supervising physician, do they still need to be enrolled?
What changed about PA billing in 2022?
What does incident-to billing actually require?
How do split or shared visits work in a hospital setting?
What does Texas require between a PA and a supervising physician?
Talk it through with a specialist.
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