Staffing to the authorization is how you end up overstaffed in March
Every ABA practice that has ever over-hired did it for a good reason.
Waitlist growing. Authorizations coming in. Referral sources happy. Somebody says we cannot keep turning families away, and they are right, and you hire.
Then March arrives and you are paying six RBTs to be available.
The arithmetic that caused it
Here is the decision as it usually gets made.
Authorized hours across the book go up by 160 a week. An RBT delivers about 27 billable hours a week once you account for cancellations, drive time and admin. 160 divided by 27 is roughly six. Hire six.
The number is right. The input is not.
Those 160 authorized hours are not 160 deliverable hours. On a 70 percent reservoir they are about 112, which is four clinicians, not six. You hired two people into work that does not exist, and you will not find out for about ninety days.
Why it takes ninety days
This is the part that makes the mistake so easy to repeat.
New hires do not deliver at full capacity immediately. There is onboarding, there is credentialing, there is client matching, there is the ramp. For the first six to eight weeks, low utilization looks exactly like a normal ramp, because it is indistinguishable from one.
By the time utilization should have levelled out, the hiring decision is a quarter old, the authorizations that justified it have partly expired, and the person reviewing the numbers is looking at a different problem.
So the cost shows up in the P&L as “clinical wages ran high this quarter” rather than as “we hired two people we did not need in December.”
What it costs
Two RBTs, illustrative, at $28 an hour fully loaded, running at 40 percent utilization instead of 85 percent for one quarter.
Illustrative arithmetic, not a client engagement.
Fourteen thousand dollars for one quarter, two people. That is the visible part.
The invisible part is worse: an RBT who spends a quarter at 40 percent utilization usually leaves, and then you pay to recruit and onboard a replacement for a role you did not need in the first place.
The fix is one number, applied earlier
Nothing about the hiring process needs to change except the input.
When someone says “authorizations went up by 160 hours,” the next question is what the reservoir ratio is on those specific clients. Not the practice average — those clients. New starts run lower than established ones. A family that just got approved for 20 hours a week is not going to do 20 hours a week in month one.
Apply the ratio, then divide by capacity per clinician, then hire. You will hire fewer people, slightly later, and they will be busy.
What to do when you are already overstaffed
Cutting is the obvious answer and it is usually the wrong one, because the ramp cost you already paid is sunk and hiring back in six months costs more than carrying through.
The better answer is to go find the hours. There are almost always authorized units sitting unused on existing clients — that is chapter 02 — and there is almost always a waitlist that has not been worked because everyone assumed there was no capacity. You now have capacity. Use it before you cut.
Cut only when the reservoir on the whole book, not the hope, says the work is not there.
Five checks you can run this week
1. Pull your last three hiring decisions and find the hours number each was based on. If it was authorized hours, you know the direction of the error.
2. Calculate utilization by clinician for the trailing quarter, billable hours over paid hours. Anyone under 60 percent past their ramp is either underscheduled or mismatched, and both are fixable this month.
3. Compute your reservoir ratio for new starts specifically, separate from established clients. If you do not have it separated, that is the finding.
4. Check the gap between authorized and delivered on your existing book before you hire anyone. Unused authorized units are cheaper capacity than a new clinician.
5. Put the reservoir ratio into the hiring template so the next person who runs the calculation cannot use the authorization by accident.
The number to actually track
Utilization by clinician — billable hours over paid hours — against a target in the mid-eighties once ramped.
Pair it with the reservoir ratio on new starts specifically, because that is the number the next hiring decision needs.
Headcount against authorized hours is the calculation that caused the problem. Do not also use it to measure it.
Where this sits
This is the first of eight stages where ABA revenue leaves, and it is the one everything downstream is measured against. The reservoir is what a client will realistically receive. Every other stage is a gap between that and what was collected.
Over-hiring is the reservoir error arriving as a payroll line rather than a revenue line, which is why it is usually attributed to something else.
A Leak Map Assessment measures all eight — the reservoir, authorization burn, cancellations, session conversion, conversion to billed, clean claims, rate integrity and recoupments. A claims audit is a different instrument. It starts once a session has been converted and billed, and reconciles the back half of the cycle to cash.
Aimline closes the books, oversees the revenue cycle, and sits in the CFO seat for ABA practices. We run claims audits scoped to a payer book, and Leak Map Assessments that measure the full cycle — three weeks, $7,500 fixed. Either one gives us a verified number to run oversight against, and the report is yours whether or not you engage us to fix what it finds.
