ABA CPT Code Changes 2027: What Retires, What Replaces It

If your practice bills ABA, the most consequential date on your calendar is January 1, 2027. That is when the AMA's CPT 2027 code set takes effect and the adaptive behavior family changes shape: new codes, narrower and clearer descriptors, and the end of both Category III T-codes. This guide is the crosswalk and the checklist. Everything below is as of November 2, 2026, and every code and date comes from the sources named in each section.

The short version

• Six new Category I codes: 97148 and add-on +97149, 97159 and add-on +97160, 97173 and 97180.
• Eight revised descriptors: 97151 through 97158 keep their numbers, but the language changes. The term "protocol modification" is replaced by "analysis" in the descriptors of the codes administered by a qualified healthcare professional (QHP).
• Two deletions: 0362T and 0373T. There is no grace period.
• Effective date: January 1, 2027, for dates of service on or after that day.

The AMA released the CPT 2027 code set on September 9, 2026, with 299 new codes across all specialties (AMA press release). The ABA Coding Coalition, whose members at the time of the application were APBA, Autism Speaks, the BACB, CASP and their CPT consultants, working with the ABAI ABA Billing Codes Commission, submitted the code change application that produced the adaptive behavior changes. Its September 11, 2026 letter and crosswalk (abacodes.org) is the primary source for the table below.

Crosswalk: 2026 codes to 2027 codes

This table paraphrases the Coalition's conversion table. "QHP" means a qualified healthcare professional such as a licensed or board certified behavior analyst. Descriptors are summarized, not quoted in full; the binding text is in the AMA's CPT 2027 Professional code book.

2026 code	2027 code	What changes
97151 assessment	97151	Same number. Wording tightened; QHP face-to-face and non-face-to-face assessment work. Cannot be billed on the same day as 97180 for the same patient.
97152 supporting assessment	97152	Same number. Technician-administered, face-to-face with the patient.
0362T supporting assessment of destructive behavior, two or more technicians	97148 plus +97149	Category III becomes Category I. Two technicians, a patient with harmful behavior, a customized environment; +97149 adds technicians three to five.
97153 treatment by protocol	97153	Same number. Wording drops "under the direction of" a QHP.
97154 group treatment by protocol	97154	Same number. The former group size maximum of 8 patients is removed.
0373T treatment with protocol modification, two or more technicians	97159 plus +97160	Category III becomes Category I. Same three components as 97148/+97149, for treatment.
97155 treatment with protocol modification, may include direction of technician	97155 plus 97173	Splits. 97155 becomes direction of a technician with analysis, patient present. QHP treating one patient alone becomes 97173.
97156 family guidance	97156	Same number; now "with analysis."
97157 multiple-family group guidance	97157	Same number; now "with analysis."
97158 group treatment with protocol modification	97158	Same number; now "with analysis."
Not separately reportable	97180	New. Non-face-to-face QHP services, reported once per week.

The full code-by-code view lives on our ABA CPT codes page.

The three changes that move money

1. 97155 stops doing two jobs

Under the current descriptor, 97155 covers a QHP's treatment with protocol modification, "which may include simultaneous direction of technician." Many practices bill every analyst hour in the home to it. From January 1 the Coalition's guidance says 97155 is "used specifically and only for QHP direction of a technician with patient(s) present," and is always reported with another code: 97148/+97149, 97153, 97154 or 97159/+97160. When the QHP delivers treatment directly to a single patient with no technician, that is 97173. The two cannot be billed concurrently, and neither can 97152 with 97155.

The Coalition's sample six-month authorization shows the effect. In 2026, 312 units of 97155 cover both uses: 208 units for directing a technician and 104 for the QHP's own one-to-one work. In 2027 that same patient is 208 units of 97155, 104 units of 97173, and 52 units of 97180. The Coalition frames this as an illustration, and says authorization should be based on medical necessity for the individual patient with no prescribed formula.

2. 97180 pays for work that was unbillable, with limits

97180 covers five things, each personally performed by the QHP: reviewing and analyzing data and session notes, deciding whether to modify targets, goals or protocols (and making the change), deciding whether more assessment is needed, developing a discharge or transition plan, and training or reviewing protocols with technicians without the patient present. It is reported once a week: document each date separately, sum the time over a 7-day period such as Sunday to Saturday, and report the total on one claim. It cannot be reported on the same day as 97151 for the same patient. The guidance also says time prior to the patient's arrival and after departure should not be counted unless it involves one of the 97180 activities.

3. The T-codes become Category I, with a QHP "on site" rule

For 97148, 97149, 97159 and 97160 the QHP must be on site and immediately available to join the session. "On site" is defined as immediately available and interruptible; the QHP does not need to be in the room. Where medically necessary and clinically appropriate, the requirement may be met by telehealth, but payer policies and state law vary, so confirm it payer by payer. If the QHP is present, that time is reported separately with 97155. And a second technician stepping in during a scheduled 97151 or 97152 session does not turn it into 97148 unless every element, including the customized environment, is met.

What is not settled

• Rates. A code number is not a rate. CMS's proposed 2027 Medicare Physician Fee Schedule rule, issued July 14, 2026, extends carrier pricing for the ABA codes through 2027, covering the existing and new codes (ABA Coding Coalition, July 15, 2026). We did not find the final rule as of November 2, 2026. Medicaid agencies and commercial plans each set their own rates.
• Payer load dates. The Coalition's guidance says all payers accepting electronic claims must use Category I codes under HIPAA, but HIPAA does not govern coverage, payment or authorization, and payers have their own procedures and timelines.
• Telehealth. The guidance says CMS added the current adaptive behavior codes to its permanent telehealth list in 2026, with coverage varying by state and payer. The July 2026 proposed rule kept 97151 to 97158 on that list; it did not say what happens to the new codes.
• The full guidelines. The Coalition's materials supplement, and do not replace, the CPT 2027 Professional book.

What a practice must do, and by when

Now through mid-November

1. Write to every payer. The Coalition published suggestions for communicating with payers on October 8, 2026. Ask in writing: the date the new codes load in their claims system, their crosswalk, the contracted rate for each new code, whether current authorizations convert automatically or need new requests, how claims spanning the transition are handled, and how they will notify you. Keep the answers in one tracker.
2. List authorizations that run past December 31. Anything naming 0362T, 0373T or 97155 needs a conversation. 0362T and 0373T cannot be billed for dates of service on or after January 1.
3. Find contracts that list codes by number. A contract naming 97151 to 97158 does not contain the six new codes. Each needs an amendment or fee schedule before you can bill them.

By mid-December

1. Sample a week of 97155 notes. Sort sessions into "analyst directed a technician with the patient present" and "analyst treated the patient alone." The second group is 97173 from January 1.
2. Log a week of non-face-to-face time. Sort each entry into the five 97180 activities or the work that is not covered, such as writing session notes.
3. Update note templates. The guidance says QHP analysis must be documented clearly, including a documented decision when nothing changes.
4. Ask your software and billing vendors for their 2027 release date. The Coalition's guidance tells providers to update EHR and billing software, add documentation templates and train staff.

December 31 and January 1

1. Build claim edits that block 97151 and 97180 on the same date for the same patient, 97155 billed alone, and 97152 with 97155.
2. Brief the team on who bills what. A QHP who fills in for a technician and simply runs the protocol bills 97153; use 97173 only when the QHP is also analyzing whether targets or protocols need to change.
3. Watch denials in January. Payers that have not loaded the codes will reject them. Track by payer and appeal against the written answers you collected.

Where tooling fits

None of this is hard to understand; it is hard to execute across dozens of authorizations, contracts and note templates at once. A system that holds each authorization by code and unit makes the list above a query rather than a spreadsheet project. That is the practical use of authorization tracking and of billing software that ties units to sessions. Wilma, our platform, includes both authorization tracking and billing, but the steps above work with any system, and no software can tell you what a particular payer will do. Always confirm against the payer's own bulletin.

Sources, with dates

• ABA Coding Coalition, 2027 CPT Code Crosswalk letter and conversion table, September 11, 2026 (abacodes.org).
• ABA Coding Coalition, Supplemental Guidance on Interpreting and Applying the 2027 CPT Codes, posted October 5, 2026 (abacodes.org).
• ABA Coding Coalition, Billing Codes page, 2027 code descriptors (abacodes.org/codes).
• AMA, press release on the CPT 2027 code set, September 9, 2026 (299 new codes; changes effective January 1).
• APBA, summary of the ABA Coding Coalition note on CMS's proposed 2027 fee schedule, July 15, 2026.

Payer rules change. Treat this as education, not billing or legal advice, and confirm with each payer and the CPT 2027 book before you bill.