ABA Startup Billing Checklist: Billing, Credentialing and Cash Flow for the First 90 Days

Starting an ABA practice is exciting. It's also expensive, slower than expected and full of billing traps that nobody warned you about.

The biggest one? You can't collect a single dollar until you're credentialed. And credentialing takes 60 to 150 days. That gap between opening your doors and receiving your first payment is where new ABA practices run into serious cash flow problems.

This ABA startup billing checklist breaks the first 90 days into three phases:

getting your paperwork in order, setting up billing before sessions start and building the daily habits that protect revenue for the long run. Each section covers what to do, when to do it and what breaks when you skip it.

Days 1-30 — ABA Credentialing and Practice Setup

This phase is all about credentialing. Nothing else in ABA billing works until this is done.

Credentialing is the process of getting your practice recognized by insurance payers so you can submit claims. Commercial insurers like Aetna and UnitedHealthcare average 60 to 90 days. Medicaid can take up to 180 days. Start the moment you decide to open.

What to complete in the first 30 days:

• Get your NPI numbers. You need a Type 1 (individual BCBA) and a Type 2 (your group practice). No NPI means no claim submission.

• Apply for your EIN. Your Employer Identification Number is required for every payer enrollment. Takes 24 hours through the IRS website.

• Set up your CAQH profile. More than 90% of commercial payers pull credentialing data directly from CAQH. A complete, attested profile speeds up every application you submit. Incomplete CAQH is the number one reason for credentialing delays.

• Submit to your top 3 payers. Prioritize the insurers your first clients carry. Don't wait for a full list. Get the clock running on your most important payer relationships now.

One thing many new ABA providers miss: you may need a separate state Medicaid enrollment, which runs on its own timeline separate from commercial credentialing. Check your state's Medicaid managed care organization requirements early.

For a detailed breakdown of what the ABA provider credentialing process actually looks like step by step, including which documents go in first and how to avoid the most common rejection reasons, that guide covers it all.

Days 31-60 — ABA Billing Setup Before the First Session

You're credentialed (or in process). Now you build the billing infrastructure that makes clean claims possible.

The most expensive mistake new ABA practices make is treating billing as an afterthought. If you start seeing kiddos without verifying their benefits or obtaining prior authorization, you're delivering sessions you may never get paid for.

Verify Benefits Before Every Single Session

Call the insurance company or use your practice management software to confirm: Is ABA covered? How many hours are authorized? What are the copay and deductible amounts? Is the diagnosis (F84.0 or similar) listed as a covered condition?

Unverified coverage is one of the most avoidable denial categories in ABA billing. It costs nothing to check upfront and hours to fix after a denial.

Get Prior Authorization Before Services Start

Nearly every payer requires prior authorization before a single unit of ABA therapy can be billed. Authorization-related denials account for roughly 34% of all ABA claim rejections. That's the single biggest denial bucket in the specialty.

Most authorizations cover a 3 to 6 month window. Set calendar reminders at 30, 10 and 0 days before expiration. A lapsed authorization makes every session during that gap unbillable.

The ABA billing 2026 CPT and payer guidelines covers exactly which codes require authorization, how renewal documentation has gotten stricter with major payers like UnitedHealthcare and Anthem BCBS and what to include in your auth requests.

Choose ABA-Specific Billing Software

Generic medical billing tools don't understand ABA modifier logic. RBTs bill different codes than BCBAs. Time units must round correctly to the 15-minute increment. Credential-tied rules need to be automated, not manually checked every claim.

Practices that automate claim validation typically improve first-pass acceptance from 70-80% up to 95% or higher within the first quarter.

Days 61-90 — Building Cash Flow Habits That Stick

By week 9, claims should be going out. Now the job is building the daily and weekly habits that keep cash flowing and catch problems before they compound.

ABA Startup Billing Checklist: First 90 Days
Phase	Task	Why It Matters
Days 1-30	File NPI (Type 1 individual, Type 2 group)	No NPI = no claims, period
Days 1-30	Register EIN with IRS	Required for payer enrollment
Days 1-30	Create or update CAQH profile	90%+ of payers pull from CAQH
Days 1-30	Submit credentialing applications to top 3 payers	Credentialing takes 60-150 days
Days 1-30	Choose ABA-specific EMR or billing software	Generalist tools miss modifier rules
Days 31-60	Verify benefits for every client before session 1	Unverified coverage = payment risk
Days 31-60	Obtain prior authorizations (CPT 97151, 97153, 97155)	34% of denials are auth-related
Days 31-60	Set up clean claim template with correct modifiers	HN, HO, HM, HP vary by credential
Days 31-60	Build a payer-specific rules document	Each insurer has its own billing rules
Days 61-90	Submit first claims within 48 hours of session	Timely filing windows close fast
Days 61-90	Track AR aging weekly (target: under 30 days)	50+ days AR signals a cash flow leak
Days 61-90	Set authorization renewal alerts at 30/10/0 days	Expired auth = unbillable sessions
Days 61-90	Review denial report and rework within 7 days	Appealing fast recovers 30-40% more

The number that matters most in early-stage ABA practices is your clean claim rate. Industry benchmark is 95% or higher. Practices below 90% are losing collectible revenue every single month. If you're new and unsure where you stand, the common ABA billing challenges guide walks through the 7 biggest failure points in the ABA revenue cycle and the operational fix for each one.

What Breaks Most Often in an ABA Practice's First Year

Here's what the data actually shows about where new ABA practices leak revenue:

•  Authorization gaps. Sessions delivered outside an active authorization window are retroactively unbillable. No payer will pay them after the fact.

•  CAQH attestation lapses. Your CAQH profile requires re-attestation every 120 days. Let it expire and credentialing renewal stalls.

•  Wrong modifier usage. HN (bachelor's level), HO (master's level), HP (doctoral), HM (less than bachelor's) are payer-specific. Mismatched modifiers produce automatic rejections.

•  Timely filing missed. Most payers require claims within 90 to 180 days of the service date. Miss the window and there's no appeal path.

•  Denial follow-up skipped. ABA clinics that don't work denials within 7 days lose 30-40% of potentially recoverable revenue permanently.

The accounts receivable management for ABA practices guide shows how to track AR aging, spot payer-specific patterns and keep your 90+ day bucket near zero.

Frequently Asked Questions

How long does ABA credentialing take for a new practice?

Commercial payers like Aetna and UnitedHealthcare typically take 60 to 90 days. Medicaid can take up to 150 to 180 days. Starting the CAQH profile first and submitting a complete credentialing packet from the beginning cuts the most common source of delays. Plan for at least 90 days before you can bill any claims.

Can an ABA practice see kiddos before credentialing is complete?

Yes, you can see clients. But you cannot bill insurance until you're credentialed. Some practices collect self-pay during the credentialing gap, then rebill insurance retroactively once approved. Ask each payer if they allow backdated claims and what documentation is required to support them. Not all payers accept retro-billing.

What CPT codes do new ABA practices bill most often?

New practices most commonly bill 97151 (assessment by BCBA), 97153 (direct therapy by RBT), and 97155 (BCBA supervision during RBT session). Each code has credential-specific requirements. RBTs cannot bill 97155. BCBAs typically don't bill 97153 for protocol-following sessions. Getting these pairings wrong produces immediate rejections.

Your First 90 Days Set the Revenue Pattern for Your Whole Practice

The billing decisions you make before session one determine whether you're chasing denials in month six or collecting at 95% clean claim rate.

Start credentialing as early as you can. Build benefit verification into intake as a non-negotiable step. Get prior authorizations before sessions start, not after. And treat denial follow-up as a weekly habit, not a monthly cleanup.

If you want a team that handles the billing side so you can stay focused on clinical care, Pacemave works exclusively with ABA providers. We carry a 98.9% clean claim rate and an 18-day average AR. Our team manages credentialing, authorizations, claims and denial follow-up so your revenue cycle doesn't stall while you're building your practice.