ABA billable units are not a rounding convention your billing team gets to choose. Florida Medicaid sets the arithmetic in writing, and the rule is that leftover minutes count only when they reach eight. If your agency bills behavior analysis in fifteen-minute increments, you need to know that a documented 52-minute session is three units and not four — because the difference between those two numbers, repeated across a caseload for a year, is the cleanest overpayment finding an auditor can make.
A billable unit is fifteen minutes of a covered service, delivered by a practitioner permitted to render it, documented in a signed note, and falling inside an authorized period. The arithmetic sits in section 8.2 of the Florida Medicaid Behavior Analysis Services Coverage Policy, incorporated by reference in Rule 59G-4.125, Florida Administrative Code. The codes and their limits sit in the Behavior Analysis Fee Schedule, incorporated by reference in Rule 59G-4.002, Florida Administrative Code.
Prerequisites: Three Things Before You Count Minutes
Know which claim form and which delivery system. Section 8.2 specifies the claim type as “Professional (837P/CMS-1500).” Sections 8.1 and 7.1 both state that the reimbursement and authorization information in the policy “is applicable to the fee-for-service delivery system” — and since February 1, 2025 most behavior analysis volume is paid by Statewide Medicaid Managed Care plans. The coverage standards apply either way; the payment terms come from the plan contract.
Use the current fee schedule. There is a live inconsistency worth knowing about: Rule 59G-4.002 lists an updated Behavior Analysis Fee Schedule for January 2026, while the Agency’s Behavior Analysis Services Information page still links a version dated October 1, 2024. Two Agency sources, two answers. Confirm which schedule the plan or the Agency is applying before you rely on unit maximums.
Have the documented duration, not the scheduled duration. The scheduled appointment is 60 minutes. The unit count follows the documented duration in the signed session note. Those two numbers diverge constantly, and only one of them is evidence.
The Eight-Minute Rule, Exactly as Written
Section 8.2 states: “Providers must only claim reimbursement for services performed for 8 minutes or more when determining the number of billable 15-minute units.”
For services running longer than fifteen minutes, the policy sets out the method: divide the total minutes of service by 15. Then, “The remaining minutes of service, if greater than or equal to 8 minutes, count as one unit”, and “The remaining minutes, when less than 8, do not count as a unit and are not reimbursable.”
Worked through, that produces the following:
- 7 minutes — not billable at all. Below the eight-minute floor.
- 8 to 22 minutes — one unit. (8 to 14 is the floor met; 15 gives one unit with 0 remaining; 15 plus 7 leftover is still one unit.)
- 23 to 37 minutes — two units. (15 plus 8 leftover reaches the second unit.)
- 38 to 52 minutes — three units.
- 53 to 67 minutes — four units.
The pattern is simple once you see it: each unit needs a full fifteen minutes except the last, which needs only eight. And the corollary is the one that catches agencies: a 52-minute session is three units, because the leftover after three full increments is seven minutes, and seven is below the floor.
Two sentences of policy. Nearly all unit-level findings in behavior analysis come out of them.
Where the Minutes Go Missing
The arithmetic is easy. The inputs are where files fail.
Documentation time is inside the duration. Writing the note is not the service. If a technician documents a 60-minute block for a session that included ten minutes of charting, the documented duration overstates the service by ten minutes — which is often exactly the difference between three units and four.
Travel is inside the duration. Section 5.2 lists “Travel Time” as non-covered. A unit with travel embedded in its documented duration carries a non-covered component, and in a home-based or school-based model this is the single most common contamination. The full exclusion list is in ABA non covered services under Florida Medicaid.
Setup, transition and parent conversation at the door. Each of these may or may not be part of the covered service depending on what it is and how the note describes it. What is certain is that a duration that silently absorbs all of them will not survive reconciliation against the note’s own description of the session.
The schedule was billed instead of the session. A practice that bills from the appointment calendar rather than from signed notes is not billing units. It is billing intentions.
The Unit Maximums That Apply to Assessment, Not Treatment
This is a distinction that produces avoidable denials, because agencies apply caps where none exist and miss the ones that do.
The fee schedule sets unit maximums on assessment codes:
- 97151, behavior identification assessment — a maximum of 24 units per behavior assessment
- 97152, supporting assessment — a maximum of 8 units
- 0362T, assessment add-on practitioner — a maximum of 16 units, and the need must be prior authorized and determined to be medically necessary
- 97151 with modifier TS, reassessment — a maximum of 18 units
The treatment codes carry no unit maximum in the fee schedule. 97153 (treatment by protocol), 97155 (treatment with protocol modification), and the group codes 97154 and 97158 are not capped there.
That does not mean treatment is uncapped. It means the limit comes from somewhere else — from section 4.2.2 of the coverage policy, which provides that “Florida Medicaid covers up to 40 hours per week of BA intervention services as indicated in the recipient’s prior-authorized behavior plan”, and from the authorized plan itself, which under section 6.2.2 must state “the number of units requested” by procedure code together with the medical necessity of those units.
So there are three separate ceilings, and a week can breach any one of them: the weekly 40-hour cap, the units the plan authorized by code, and the assessment maximums in the fee schedule. Do not attribute the 40-hour cap to the fee schedule — it is not there.
Two Codes That Exist Specifically Not to Be Paid
The fee schedule carries entries for concurrent supervision that are marked non-reimbursable, and they exist to make a billing rule visible.
97155 with modifier XP is described as treatment with protocol modification “under concurrent supervision, per 15 minutes, nonreimbursable”, with the note “Supervisee only, supervisor may be reimbursed using 97155 or 97155HN.”
97153 with modifier XP carries the parallel note: “Supervisee only, supervisor may be reimbursed using 97153, 97155 or 97155HN.”
The principle behind both is section 8.5.1 of the coverage policy: “The supervisor may be reimbursed for observing a supervisee implementing the behavior plan. The supervisee will not be reimbursed when the supervisor is reimbursed for the same time period.” One time period, one payment. The full billing analysis is in where Florida Medicaid stops paying for supervision.
The fee schedule reinforces it in a footnote: “One BA practitioner’s services are reimbursable when concurrent services are provided by more than one BA practitioner, unless determined to be medically necessary, prior authorized, and indicated in the approved behavior plan.”
One caution about how to describe modifiers publicly. The fee schedule contains no legend defining them. The meanings of HN, GT, TS and XP are derived from the limitation text in each row, and the client-count modifiers UN through US are derived from the row descriptions. Treat those meanings as read off the schedule rather than as definitions the Agency has published.
The Diagnosis Side of the Claim
Two requirements that are easy to satisfy and easy to forget.
Section 8.4 requires that providers “report the most current and appropriate diagnosis code to the highest level of specificity that supports medical necessity.” Highest level of specificity. An unspecified code on a claim for intensive intervention is a mismatch between what the claim asks for and what it documents.
Section 8.4.1 adds: “Providers must report diagnoses of co-occurring disorders that may impact the medical necessity for BA services.” Co-occurring disorders are not optional detail. They are frequently the strongest part of a medical necessity argument, and omitting them makes the case for intensity weaker than the record actually supports.
Troubleshooting: Where Units Fail
Rounding up on the last increment. Seven leftover minutes is not a unit. This is the error, and it is systematic when a billing system rounds rather than applying the eight-minute floor.
Billing from the schedule. Reconcile units against signed notes, line by line, for a full quarter. Most agencies find all three failure modes at once: units with no note, notes with no claim, and duration billed exceeding duration documented.
Documentation and travel folded into duration. Both inflate the unit count, and travel is separately non-covered.
Assessment maximums exceeded. 24 units on 97151, 8 on 97152, 16 on 0362T, 18 on 97151 TS. These are hard limits in the fee schedule.
Treatment billed above what the plan authorized. The plan states units by code. A week inside the 40-hour cap that exceeds the plan’s authorized units still fails.
XP-modified time submitted for payment. Those entries are marked non-reimbursable by design.
Relying on the wrong fee schedule. Two Agency sources currently point to different versions. Confirm before you rely on a maximum.
Expected Outcome: A Claim That Reconciles to the Minute
Unit billing is in order when three reconciliations come out clean. Documented duration in the signed note matches the minutes billed, with no documentation time and no travel inside it. The unit count follows the eight-minute rule rather than a rounding setting. And the total for the week sits inside all three ceilings at once — the 40-hour cap, the units the plan authorized by code, and any assessment maximum that applies.
Three checks, all arithmetic, all doable on a spreadsheet. Which is why this is the finding an auditor reaches first and the one an agency can close fastest. How the rest of the file is tested is set out in what a Florida Medicaid behavior analysis audit actually examines, and the group-setting variation in ABA group services under Florida Medicaid.
Frequently Asked Questions
How many units is a 52-minute ABA session?
Three. Fifty-two minutes divided by fifteen gives three full increments with seven minutes remaining, and section 8.2 provides that remaining minutes under eight “do not count as a unit and are not reimbursable.”
What is the minimum billable time for an ABA service in Florida?
Eight minutes. Section 8.2 requires that providers only claim reimbursement for services performed for eight minutes or more when determining billable fifteen-minute units.
Is documentation time billable?
The unit covers the service. A documented duration that includes charting time overstates the service, and travel time is expressly non-covered under section 5.2.
Do treatment codes have unit maximums?
Not in the fee schedule. The limits on treatment come from the 40-hour weekly cap in section 4.2.2 of the coverage policy and from the units the authorized behavior plan requested by code.
Why does the fee schedule list codes as non-reimbursable?
The XP-modified entries record time under concurrent supervision. Under section 8.5.1, the supervisee is not reimbursed when the supervisor is reimbursed for the same time period, so those entries exist to identify the time rather than to pay it.
Which fee schedule version applies?
Rule 59G-4.002 lists an updated schedule for January 2026, while the Agency’s behavior analysis information page still links an October 1, 2024 version. Confirm which one the payor is applying rather than assuming.
The decision rule is simple: count from the note, not the calendar, and never award a unit to fewer than eight leftover minutes. If your billing system rounds, it is producing findings on your behalf.
If your agency has received an overpayment demand built on unit-level findings, early legal review helps test both the claim-level determinations and the method behind the projection, and preserves internal analysis under attorney-client privilege where applicable. The firm’s work in Medicare and Medicaid overpayments appears among its practice areas.
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This article is for general information purposes only and should not be taken as legal advice for any individual case or situation. Reading it, or corresponding with us through this site, is not intended to create and does not create an attorney-client relationship. Federal and Florida healthcare regulations change frequently, and how any rule applies depends on the specific facts of your arrangement, your payor contracts, and your jurisdiction. Vitale, Suarez & Associates, P.A. is based in Miami Lakes, Florida and represents clients in Florida. If you have received an audit notice, records request, subpoena, civil investigative demand, or overpayment demand, speak with a licensed attorney before you respond.
About the author
Peter Suarez is the President of Vitale, Suarez & Associates, P.A. in Miami Lakes, Florida. He has worked in healthcare law at the firm — founded in 1982 — for 38 years, first as a Florida Registered Paralegal and Office Administrator, and was admitted to The Florida Bar in 2025. He is a member of the American Health Law Association.
