Can You Bill ABA Therapy After an Authorization Expires? What Providers Need to Know

An ABA authorization can expire while treatment is still clinically necessary. The client remains on the schedule, the technician is ready for the next session, and the BCBA may already have submitted the reauthorization request.

Billing, however, follows the authorization period.

Once the authorization end date passes, providers should not assume that later ABA sessions will be reimbursed. Whether those services can be billed depends on the payer's rules, the effective date of the new authorization, remaining units, and whether the payer allows an extension or retrospective authorization.

Here is what ABA providers should check before an authorization gap becomes a denial or aging A/R.

Can you bill ABA therapy after an authorization expires

In most cases, providers should not assume that ABA therapy delivered after an authorization expires will be paid.

An authorization normally applies to a defined period and may also limit specific ABA CPT codes, units, providers, and places of service. Once that period ends, the old authorization number does not automatically continue covering new dates of service.

For example, a client may have CPT 97153 approved through September 30 with 60 unused units still showing in the practice’s tracker. Those unused units do not necessarily remain valid on October 1. The payer approved both the number of units and the time period in which they could be used.

This is where ABA billing can become complicated. Clinically, there may be no reason to interrupt therapy. From the payer’s side, however, there may be no active approval for the next session.

Some payers may allow a backdated authorization, an extension, or a limited retrospective review. Others may require a new approval before additional treatment is covered. The practice has to verify the payer’s rule rather than assuming the next authorization will fill the gap later.

What happens to ABA claims after an authorization expires

An ABA claim can be coded correctly and still be denied if the ABA authorization ended before the date of service. Complete notes, the right CPT code, and an enrolled provider do not fix a service date that falls outside the approved period.

An expired authorization is different from a coding error. The practice may need to request a retrospective review or appeal the denial, depending on the payer's rules. If there is a gap between the old and new authorization, those dates may also remain unpaid unless the payer approves coverage for them.

For aba billing services, the team should check more than the authorization number. The authorization must match the date of service, CPT code, approved units, rendering provider, and service location.

What denial codes appear on post-expiration claims

Authorization-related denials can include CO-197 for missing or invalid authorization and CO-198 when an authorization or precertification limit has been exceeded. The exact reason still needs to be confirmed against the payer's authorization record.

Before resubmitting the claim, compare the billed date, CPT code, units, provider, and authorization dates. This helps determine whether the problem is an expired authorization, exhausted units, or another mismatch.

When can an ABA authorization be backdated or retro-authorized

Backdating is not automatic. Some payers may allow retroactive authorization in limited situations, such as a timely reauthorization request that was still pending because of payer processing delays. Other plans may have different rules.

Because payer policies vary, providers should not assume that an expired aba authorization can be fixed after treatment. If retroactive approval is granted, confirm the effective dates, CPT codes, units, provider, and location before billing the affected services.

Reauthorization submission timeline

A practical aba billing workflow should start the reauthorization process about 30 to 60 days before the current authorization ends. This gives the clinical and billing teams time to review utilization, update documentation, and address missing payer requirements.

As the expiration date approaches, confirm that the payer received the request and that no additional records are needed. Most importantly, check the approved effective date. A submission date does not automatically mean the new authorization has started.

What the Practice Should Do When Authorization Expires Before Reapproval

If ABA authorization expires while reapproval is pending, check the old authorization, remaining units, CPT codes, and provider details. Confirm the new request status with the payer, then update scheduling and billing. ABA billing services should hold affected claims until coverage is clear. Using electronic prior authorization can also make submission tracking easier by giving the authorization team a centralized way to monitor requests, status updates, and payer communication.

What documentation supports ABA reauthorization

A strong reauthorization request should explain why continued ABA treatment is needed based on the client's current progress and treatment needs.

The clinical record should support current goals, progress, behavior data, mastered skills, new targets, caregiver involvement, requested treatment hours, and any barriers affecting progress. The requested level of care should also make sense when compared with actual service use.

This is where ABA billing services, clinical documentation, and payer requirements come together. Clear documentation gives the payer a better basis for deciding whether continued ABA treatment is supported.

For practices managing frequent authorization renewals, ABA billing companies and specialized aba credentialing services can also help keep payer requirements, provider information, and billing workflows organized.

Common ABA authorization mistakes that lead to billing problems

Most authorization problems are not unusual. They are repeated workflow mistakes.

A practice waits until the last week to submit reauthorization. Another assumes that because the payer portal says pending, the sessions are safe to continue. Someone else sees unused units and overlooks the fact that the authorization date has already passed.

There can also be provider-side issues. A valid authorization does not fix an enrollment problem. If the rendering clinician is not properly connected to the payer, the claim can still fail.

That is why ABA credentialing services should not operate completely separately from authorization and billing. Changes in provider enrollment can affect whether an otherwise valid claim is payable.

The same principle applies to ABA billing services. The billing team has to know more than the claim code. They need to understand whether the authorization matches the date, provider, units, and service being billed. These mistakes are often part of a larger authorization workflow problem. Review the common ABA prior authorization errors that can cause delays, denials, and authorization gaps.

FAQ

1.Does ABA therapy require prior authorization? 

Usually, yes. Most insurers require prior authorization before ABA treatment begins or continues. Always confirm the patient’s plan, approved CPT codes, units, dates, and provider requirements before scheduling services care. 

2.How to prevent an ABA authorization gap?

Track authorization end dates and remaining units together. Start reauthorization early, keep clinical documents ready, confirm payer receipt, follow pending requests closely, and verify the new approval before treatment continues. 

3.What are the changes to the ABA CPT codes in 2027? 

Starting January 1, 2027, ABA coding will expand with six new CPT codes, revisions to 97151–97158, updated guidelines, and deletion of existing temporary T codes for adaptive behavior services nationwide. See our 2027 ABA CPT code changes guide for the complete list of new, revised, and deleted codes.