2027 ABA CPT Code Changes: New Codes, Billing Rules & Payer Implementation

The American Medical Association (AMA) released the 2027 CPT code set with major changes for applied behavior analysis (ABA) and adaptive behavior services, effective January 1, 2027. The 2027 ABA CPT code changes expand the adaptive behavior family from 10 to 14 codes, adding six new Category I codes: 97148, 97149, 97159, 97160, 97173 and 97180. Codes 97151 through 97158 are revised, with 97155 substantially redefined to separate directing a technician from direct client treatment, while temporary T-codes 0362T and 0373T are permanently deleted. Codes 97148 and 97159 take over harmful behavior assessment and treatment with two technicians, add-on codes 97149 and 97160 cover each extra technician and BCBA analysis and non-face-to-face work that was previously unbillable now has dedicated codes.

Before January 1, 2027, review your billing workflows and practice management systems against the official 2019-to-2027 code crosswalk, then verify each payer’s authorization policies, fee schedules and coverage rules, because permanent code status does not guarantee automatic reimbursement. The 2027 ABA CPT code changes take effect on January 1, 2027. The American Medical Association (AMA) added six new adaptive behavior codes (97148, 97149, 97159, 97160, 97173 and 97180), revised 97151 through 97158 and deleted the temporary codes 0362T and 0373T. ABA billing moves from 10 codes to 14 permanent Category I codes.

The six new numbers are the easy part. The risk sits in authorizations, fee schedules and session notes built on the old set, which can stop matching your claims overnight.

What are the 2027 ABA CPT code changes and why now?

The AMA's CPT Editorial Panel approved this update in September 2025 and the AMA published the final 2027 code set on September 9, 2026. It's the first full rewrite since 2019, when the set covered in our 2026 ABA CPT code guide took effect.

What the update fixes:

• A BCBA's data review, protocol rewrites and patient-specific technician training finally get their own code, 97180.

• The high-risk team codes are permanent now. 0362T and 0373T were temporary and payer coverage was patchy.

• Old 97155 mixed two services, so it's split between 97155 and 97173.

• The wording changed. "Protocol modification" became "analysis" and "destructive behavior" became the wider "harmful behavior," which covers pica, elopement and feeding problems.

  
  

2027 ABA CPT codes at a glance: what's new and what it replaces

Every code bills in 15-minute units (8 to 22 minutes is one unit). In its CY 2027 Physician Fee Schedule proposed rule, CMS proposed carrier pricing for all 14 codes, which means no national Medicare rate.

Which 2027 ABA CPT billing rules cause the most denials?

Most denials will come from five old habits:

1. Billing 97155 alone. In 2027, 97155 always pairs with a technician code such as CPT 97153, 97154 or 97159. A BCBA working one-on-one without a technician bills 97173, which can't overlap with 97155.

2. Using 97180 as a catch-all. Log each date, total the week's minutes (Sunday to Saturday) and bill them on one claim line. Session notes, internal audits and general staff training don't qualify.

3. Stacking 97180 and 97151 on one day. Not allowed for the same patient. Assessment and report writing stay on 97151.

4. Billing add-ons without a parent. 97149 and 97160 only ride with 97148 or 97159, cover up to three extra technicians and you total their time before rounding.

5. Growing groups past 8. CPT dropped the 8-patient cap for 97154, 97157 and 97158, but payers can keep theirs.

Example: A BCBA coaches an RBT for 45 minutes, so bill 3 units of 97155 next to the RBT's 97153. Her 30 minutes rewriting the protocol that evening is 97180 time, billed with the rest of the week.

How are payers implementing the 2027 ABA CPT code changes?

Under HIPAA, payers that take electronic claims must accept valid Category I codes. Coverage, rates and authorization rules stay each payer's call, on its own timeline.

• Commercial plans need to load the codes, update fee schedules and decide whether old authorizations convert.

• Medicaid programs may need rate setting, a state plan amendment and a claims system update first, which can run past January 1.

• Medicare telehealth for the new codes needs a check. CMS proposed keeping 97151 through 97158 on the permanent list but didn't address the six new ones. Confirm against the November 4, 2026 final rule and your payers before booking virtual sessions on them.

There's no grace period. A 0362T or 0373T line dated January 1, 2027 or later will likely deny with CARC 181 (procedure code invalid on date of service). Sessions billed on an authorization that still lists old codes risk CARC 197 (authorization absent). That's why prior authorization in ABA therapy billing needs attention this quarter.

How one 26-week authorization changes:

Is your practice ready for the 2027 ABA CPT code changes?

Run this list before your first January schedule goes out:

• Pull every authorization running past December 31 that lists 0362T, 0373T or 97155.

• Ask each payer, in writing, whether those authorizations convert or need a new request.

• Load the six new codes in your EHR, clearinghouse and charge sheets from January 1, 2027 and end-date 0362T and 0373T on December 31, 2026.

• Add payer rates for 97173 and 97180 as each payer confirms them.

• Update session note templates to show who delivered each service and what analysis happened, then train BCBAs on the 97155, 97173 and 97180 split.

• Check early January remits for 181 and 197 denials.

If your team is stretched thin, our ABA therapy billing services team can run this cutover for you, from authorization audits to claim checks against the 2027 code set.

2027 ABA CPT code changes FAQs

What are the new 2027 ABA CPT codes?

There are six new ABA cpt code gait training for 2027: 97148 and add-on 97149 for harmful behavior assessment, 97159 and add-on 97160 for harmful behavior treatment, 97173 for BCBA one-on-one treatment with analysis and 97180 for BCBA work done without the patient. All start January 1, 2027, in 15-minute units.

What replaced 0362T and 0373T in the 2027 ABA CPT code changes?

Codes 97148 and 97149 replace 0362T for assessing harmful behavior and 97159 and 97160 replace 0373T for treating it. Each needs two technicians, a patient with harmful behavior, a customized setting and a BCBA on site. 0362T and 0373T are invalid for dates of service on or after January 1, 2027.

How does CPT 97155 change under the 2027 ABA CPT codes?

In 2027, CPT 97155 covers only a BCBA directing a technician while the patient is present, so it's always billed alongside a technician code. When a BCBA treats the patient one-on-one with no technician, bill 97173. Data review and protocol rewrites done away from the patient move to 97180.