5 Common Billing Mistakes That Hurt Your Practice’s Cash Flow

Even the most organized therapy practices can lose revenue from preventable billing mistakes. These errors may seem small in the moment, but over time, they build up into significant financial losses, administrative strain, and unhappy clients.

From incorrect codes to weak patient collections, each breakdown in the revenue cycle slows down your payments and hurts your practice’s long-term sustainability. In this blog, we’ll highlight five of the most common billing mistakes we see in ABA and therapy practices and share simple tips to avoid them.

We'll also explore the ripple effect of these errors and how small adjustments can significantly improve cash flow.

1. Using Incorrect or Outdated Codes

Insurance payers are strict about coding accuracy. Claims that contain the wrong CPT, HCPCS, or diagnosis codes are immediately flagged and denied. This is especially risky in ABA and therapy practices where code sets are frequently updated.

Outdated or incorrect codes don’t just delay payment—they can result in compliance issues, reprocessing costs, and potential audits. A simple code error can take weeks to resolve, and in some cases, payers will not accept corrections past their deadline.

Tips: 

• Stay current on code updates by subscribing to payer newsletters or using a billing system that alerts you to changes. Better yet, outsource to an ABA-specialized billing team that understands therapy-specific coding.

• Regularly audit a random sampling of claims to ensure codes match service documentation.

2. Missing Prior Authorizations

Starting services before authorization is received is a surefire way to lose revenue. Insurance companies require pre-approval for most ABA, speech, and OT services, and claims submitted without proof of authorization are typically denied.

Authorization errors often happen when staff assume an existing auth is still valid or forget to track expiration dates. Because appeals for these denials are rarely successful, it's critical to catch issues before the session happens.

Tips: 

• Implement an internal authorization tracker. Include the date authorized, number of units approved, expiration date, and number of remaining sessions. Assign a staff member to review this weekly.

• Automate expiration alerts using your practice management system or a shared spreadsheet with conditional formatting.

3. Submitting Claims Too Late

Each insurance company sets a strict deadline for when claims must be submitted—often within 90 or 180 days of service. If you miss the window, there’s usually no way to appeal or resubmit. That revenue is gone.

Late submissions often result from delays in documentation, miscommunication between clinical and billing teams, or lack of internal accountability. This is one of the easiest problems to fix with the right workflow.

Tip: 

• Set internal claim submission deadlines at least 5–7 business days before the payer's actual cutoff. This allows time for corrections and resubmissions.

• Use a weekly dashboard that flags unbilled sessions and aging documentation.

4. Overlooking Secondary Insurance

Many clients have both primary and secondary insurance, and when the secondary claim isn’t submitted, practices leave money on the table. This often happens because intake staff didn’t collect the secondary plan, or billers assumed the primary would cover all charges.

Secondary claims are vital for maximizing reimbursement—especially when the primary payer leaves a balance. Filing both claims ensures the family isn’t overcharged and your practice collects every dollar it's owed.

Tip: 

• Ask all new clients if they have a secondary plan. Include it as a required intake field.

• Build secondary claim submission into your regular billing workflow. If you're not using automation for this, you're missing out on thousands annually.

5. Weak Patient Collections

Many therapy practices are hesitant to collect payment from families at the time of service. But if you don’t collect copays, coinsurance, or deductibles upfront, you’re relying on manual invoicing and chasing down balances—which often go unpaid.

Weak collections also send the wrong message: that your services can be accessed without financial accountability. Families are more likely to pay when expectations are clear and consistent from the start.

Tip: 

• Use a script to explain financial policies during intake. Collect copays at check-in and offer digital payment options for flexibility.

• Train front-desk staff to be confident when discussing fees and set monthly collection goals to track progress.

Wrap-Up

Billing mistakes cost more than just time—they drain your cash flow, frustrate your team, and reduce the stability of your business. But the good news is that these mistakes are preventable. With strong systems, clear workflows, and the right training, your practice can plug revenue leaks before they turn into major losses.

If you're seeing delays in payments, high denial rates, or unpaid patient balances, it might be time for a billing audit. A few adjustments could save your team hours each week and increase your revenue significantly.