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BCBSIL

BCBSIL Clarifies Pass-Through and Trainee Billing: Whose NPI Goes on the Claim?

By Dax Earl • June 24, 2026

Last updated: June 24, 2026.

Blue Cross and Blue Shield of Illinois has clarified an important distinction for behavioral health practices: a licensed provider who performs a service should generally bill under their own rendering NPI. A practice should not submit the claim under another clinician's NPI simply because that clinician is contracted with BCBSIL. Read the May 12, 2026 BCBSIL reminder.

The main exception is a formal supervisor and trainee relationship. Covered services performed by an eligible behavioral health trainee may be billed under the supervising contracted clinician's NPI, but BCBSIL requires direct supervision and compliance with Illinois licensing rules.

The practical question for group practices: did a trainee perform the session, or did another licensed clinician perform it? That answer determines whose rendering NPI belongs on the claim.

Adding interns, associates, or new clinicians in Illinois? Bomi helps growing therapy groups turn supervision, credentialing, roster, and claim-routing rules into a working billing process.

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TL;DR

  • No pass-through billing. BCBSIL says claims may not be submitted under the NPI of someone who did not render the service unless there is a formal supervisor-trainee relationship.

  • Licensed clinicians generally use their own rendering NPI. A licensed clinician who is not a trainee should not be mapped to another clinician's NPI just because the other clinician is already contracted.

  • Trainee billing is a specific exception. Covered services by qualifying behavioral health trainees may be billed under the supervising contracted clinician's NPI.

  • HL is not active yet. BCBSIL says an HL modifier requirement is planned for future trainee identification, but providers should not append HL until BCBSIL communicates implementation.

What BCBSIL Means by Pass-Through Billing

Pass-through billing happens when one clinician provides the service but the claim is submitted as though another clinician provided it.

Imagine an LCPC practice owner employs another licensed clinician who is not yet credentialed with BCBSIL. The employee sees the client, but the claim lists the owner as the rendering provider because the owner is already contracted.

BCBSIL says that is not allowed unless there is a qualifying supervisor and trainee relationship. The plan says out-of-network providers may be added to a group practice, but they should bill under their own rendering NPI and work within their scope of practice. BCBSIL also says submitting a claim under an individual NPI certifies that the individual performed the service. See BCBSIL's claims reminder.

This does not mean the group cannot appear as the billing organization. It means the claim must accurately identify the person who actually delivered the care.

Being part of a group does not make every clinician interchangeable on the claim.

Who Should Appear as the Rendering Provider?

The easiest way to remember the distinction is to start with the person who performed the session.

  • Fully licensed clinician who is not a trainee: use that clinician's own rendering NPI.

  • Licensed but noncredentialed provider, such as an eligible LPC or LSW: use that clinician's own rendering NPI.

  • Out-of-network qualified provider added to the group: use that clinician's own rendering NPI.

  • Eligible unlicensed intern or postdoctoral trainee under formal supervision: BCBSIL says covered trainee services are billed under the supervising contracted clinician's NPI.

BCBSIL has previously explained that certain licensed but noncredentialed provider types may be added to a group and bill under their own rendering NPIs. Once an LSW or LPC becomes fully licensed as an LCSW or LCPC and completes credentialing, the practice may need to add that provider to the group again under the new status. Read BCBSIL's trainee and noncredentialed provider reminder.

The important point: "receives supervision" does not automatically mean "trainee."

Many licensed clinicians receive supervision while working toward independent licensure. BCBSIL's billing guidance still distinguishes those licensed clinicians from unlicensed behavioral health interns and postdoctoral fellows.

When Can a Trainee Bill Under the Supervisor's NPI?

BCBSIL allows supervisory billing when there is a formal supervisor and trainee relationship.

The trainee must be working toward clinical state licensure under a fully licensed, contracted provider. BCBSIL's examples include master's-level interns, doctoral interns, and postdoctoral fellows in psychology, social work, and counseling. These trainees do not contract directly with BCBSIL and are not added to the group as ordinary participating clinicians. See BCBSIL's trainee guidance.

Covered services performed by the trainee are billed under the supervising clinician's rendering NPI.

This is not a general workaround for clinicians who are waiting for credentialing. It is a specific billing pathway for qualifying trainees operating within a formal supervision structure.

What Direct Supervision Means

BCBSIL says the supervising qualified healthcare provider must be available for the entire time the trainee is providing services.

The supervisor does not necessarily need to sit inside the therapy session. However, the supervisor must be reachable, reasonably accessible, and able to intervene or join the session in the same way the session is being delivered. For telehealth, that could mean being able to join remotely if necessary. Read the BCBSIL billing FAQ.

The supervision arrangement must also comply with the applicable state licensing board's requirements.

BCBSIL has additionally stated that a supervisor may supervise no more than four behavioral health trainees at one time. The trainee and supervisor should generally work within the same organization or system, although BCBSIL may make exceptions for programs serving underserved populations.

A clinic director may serve as the rendering supervisor only if there is a genuine direct supervisor-supervisee relationship and the arrangement complies with state requirements. A title alone is not enough.

What About the HL Modifier?

BCBSIL says it plans to require the HL modifier in the future to identify services performed by a trainee.

But practices should not start using it yet.

As of BCBSIL's May 12, 2026 guidance, providers were specifically instructed not to append HL until BCBSIL issues a future implementation notice. See the May 2026 reminder.

For now, the existing billing workflow remains in place. The trainee's covered service is submitted under the supervising contracted clinician's rendering NPI without the future trainee modifier.

This is worth adding to a payer update tracker. Once BCBSIL activates the modifier requirement, practices using trainees will need to update their EHR and claim rules quickly.

Why This Matters for Group Practices

This clarification matters most for practices with a mix of independently licensed clinicians, associate-level clinicians, interns, postdoctoral fellows, and providers waiting for credentialing.

It is easy for those categories to blur together operationally.

A new clinician joins the group. They are receiving supervision. They are not yet independently credentialed. The owner is already in network. The EHR defaults to the owner's NPI.

That setup may feel convenient, but it does not determine whether supervisory billing is allowed. The clinician's actual status does.

A qualifying unlicensed trainee may bill through the supervisor under BCBSIL's rules. A licensed provider who is not a trainee should generally be identified by their own rendering NPI, even if they are still supervised or not individually credentialed.

Operational warning: do not use "under supervision," "associate," "prelicensed," and "trainee" as though they all mean the same thing.

What Practices Should Review

Start by classifying every behavioral health clinician correctly.

  • Is this person an unlicensed intern or postdoctoral fellow?

  • Is this person licensed but noncredentialed?

  • Is this person independently licensed?

  • Is this person already credentialed and participating with BCBSIL?

  • Is this person receiving supervision as a trainee, or receiving supervision while already licensed?

Then review the claim setup. The provider who performed the session should appear correctly. Trainee claims should point to the appropriate supervising contracted provider. Ordinary licensed clinicians should not be mapped automatically to the owner or clinical director's rendering NPI.

The clinical documentation should also identify who performed the service and, when relevant, who supervised it. BCBSIL warns that claims and statements not supported by documentation may be delayed or denied.

Finally, remember that correct provider attribution does not guarantee payment. Reimbursement still depends on the member's benefits, the practice's contract, medical necessity, and any other applicable claim requirements.

A Quick Example

An unlicensed master's intern provides a session while working toward licensure under a formal BCBSIL-compliant supervision arrangement.

That session may be billed under the supervising contracted clinician's rendering NPI.

Now imagine an LPC employed by the same practice provides the next session. The LPC receives clinical supervision but already holds a professional license.

That claim should generally identify the LPC's own rendering NPI. The practice should not submit it under the supervisor merely because the supervisor is independently licensed or already contracted.

The sessions may look similar clinically. The billing rules are different because the providers have different statuses.

Where Bomi Fits

These are exactly the kinds of situations Bomi is very familiar with navigating: supervisor and trainee billing, noncredentialed clinicians, group roster cleanup, rendering-provider mapping, payer-specific claim rules, and EHR defaults that quietly put the wrong NPI on a claim.

If your practice is unsure whose NPI should go on the claim, Bomi can help set up and run the billing workflow so the claim reflects the provider who actually delivered care and follows the payer-specific rules that apply.

See how Bomi handles billing and credentialing.

Need help turning this into a billing workflow? If your practice is adding trainees, associates, or new locations, Bomi can help keep supervisory billing, rendering NPIs, payer rosters, credentialing, and claims aligned as the group grows.

Talk to Bomi about insurance

How Bomi helps: we spend a lot of time in exactly this messy middle, where licensure status, supervision, rosters, rendering NPIs, and payer billing rules all have to line up before the claim goes out.

Bottom Line

BCBSIL's clarification is really about accurate provider identity.

A licensed clinician who performs a service should generally bill under their own rendering NPI. A practice cannot route the claim through another clinician simply because that clinician is in network.

A qualifying trainee may bill under a supervising contracted provider, but only within a formal supervision arrangement that meets BCBSIL and state requirements.

For Illinois therapy groups, the safest workflow is to know exactly who is a trainee, who is a licensed noncredentialed provider, and who is fully credentialed. Then make sure the claim identifies the right person.

The difference between trainee billing and pass-through billing is not a technicality. It is the difference between a supported supervisory claim and a claim that says the wrong person provided the therapy.

Sources

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