If you run a therapy or counseling practice, you’ve probably noticed that insurance reimbursements don’t always match what you expected. You submit a claim, wait weeks, and get back a fraction of the amount you billed, with little explanation. This isn’t always a mistake on your end. Underpayment is a widespread issue in the industry, and it often traces back to gaps in how claims are prepared, coded, and followed up on. Practices that work with a specialized behavioral health billing team tend to catch these underpayments far earlier, simply because someone is watching the numbers closely enough to notice when they don’t add up.
Underpayment is different from denial. A denied claim gets rejected outright, but an underpaid claim gets processed and paid at a lower rate than your contract allows. Because the claim technically “went through,” many providers never realize they were shortchanged. Over a year, these small gaps between the contracted rate and the actual payment can quietly cost a practice tens of thousands of dollars.
This problem is especially common in mental health billing because reimbursement rates vary so much by code, session length, and provider credential type. A licensed psychologist and an associate-level counselor might bill the same code but receive different contracted rates. If your billing system isn’t matching each payment against the correct contracted amount, underpayments slip through unnoticed.
Insurers aren’t necessarily acting in bad faith. Payment errors happen on their end too, from outdated fee schedules in their system to processing glitches. But insurers rarely flag their own underpayments. It’s on the provider to catch them, and most practices simply don’t have the bandwidth to audit every payment against every contract.
A Group Practice Case Study
Picture a group practice with six therapists, all billing under the same tax ID. The office manager handling billing was talented but overworked, juggling scheduling, client intake, and claims submission all at once. Payments came in regularly, so nothing seemed obviously wrong.
A year-end financial review told a different story. When a consultant cross-checked payments against the practice’s actual payer contracts, they found that three of the four major insurers on their panel were paying roughly 8 to 12 percent below the contracted rate for certain codes. The fee schedule the insurer used internally hadn’t been updated after the practice renegotiated rates the previous year.
Because nobody was checking payments line by line, this had been happening for nearly ten months. The total shortfall came to just over $27,000 across all six therapists. The practice was eventually able to recover a portion of it through a formal appeal, but insurers typically only allow a limited window, often 90 to 180 days, to dispute a payment. Some of the older underpayments were simply gone for good.
This kind of story is far more common than most providers realize. It rarely comes from dramatic fraud. It comes from nobody having the time to check whether every payment actually matches the contract.
The Legal and Financial Risk Providers Don’t Always See
Underpayment itself isn’t illegal on the provider’s end, but the surrounding practices that often accompany it can create real exposure.
Failure to appeal within contractual deadlines can waive your rights. Most payer contracts include strict timelines for disputing incorrect payments. Miss that window, even by a few days, and the insurer has no further obligation to correct the error, regardless of how clear the mistake was.
Writing off balances incorrectly can trigger compliance issues. Some practices, frustrated by chasing small underpayments, simply write off the difference. For Medicare and Medicaid claims, routinely writing off balances without proper documentation can raise questions during an audit, since it may look like inconsistent billing practices across patients.
Balance billing violations. In some states, attempting to bill the client directly for the gap between what the insurer paid and what was contracted can violate balance billing laws, particularly under the No Surprises Act for certain types of care. Providers need to understand exactly what they’re legally allowed to collect from a client versus what must be pursued through the insurer.
Contract breach claims work both ways. While it’s less common, providers who don’t actively track underpayments and simply accept whatever an insurer pays may unintentionally weaken their negotiating position during future contract renewals, since payment history gets used as a baseline.
None of this means providers are in constant legal danger. But it does mean that treating every payment as final, without verification, carries hidden risk beyond the lost revenue itself.
Red Flags That You’re Being Underpaid
Most practices don’t have a system built specifically to catch underpayment, so these signs are worth watching for manually.
Payments that vary for identical codes. If the same CPT code from the same insurer produces different payment amounts on different claims, without an obvious reason like a modifier difference, something is off.
No explanation of benefits detail. A vague EOB that doesn’t clearly break down the allowed amount versus the paid amount makes it nearly impossible to verify accuracy. This is worth flagging with the payer directly.
Rates that haven’t moved in years. If your contracted rates were renegotiated but your payments look identical to what you received three years ago, the insurer’s system may still be using an outdated fee schedule.
Consistently low reimbursement compared to peers. If colleagues in your area report noticeably higher payments from the same insurer for the same code, it’s worth requesting a formal rate comparison.
High volume, flat revenue. If your session count is climbing but your revenue per session is flat or shrinking, underpayment is one of the more likely explanations, especially if your fee schedule hasn’t changed.
Prevention Tips for Catching Underpayment Early
Keep a master rate sheet. Maintain a simple, updated document listing your contracted rate for every code with every payer. Without this reference, it’s nearly impossible to spot when a payment is short.
Audit payments monthly, not annually. Waiting until year-end to review payments, like in the case study above, means months of underpayment go unnoticed and appeal windows may already be closing.
Compare EOBs against contracts directly. Don’t rely on the total deposit amount alone. Break down each claim and check it against your actual contracted rate for that specific code and provider type.
Flag discrepancies immediately. The moment you notice a mismatch, submit a written appeal rather than waiting to see if it resolves itself. Insurers rarely correct errors proactively.
Renegotiate rates periodically. Behavioral health reimbursement rates have shifted significantly in recent years due to parity law enforcement. Practices that haven’t renegotiated in several years may be leaving money on the table even beyond outright errors.
Bring in outside expertise for contract review. Understanding the fine print of payer contracts takes specialized knowledge that most clinical staff simply haven’t been trained in. A billing partner familiar with behavioral health contracts can spot discrepancies that would otherwise slip through. This is exactly the kind of oversight that a specialized billing and revenue cycle partner provides. Working with an experienced team like Practice Revenue Partners means every payment gets checked against your actual contract terms, not just processed and filed away.
What to Ask Before Trusting Your Billing Process
Every practice, whether solo or group, should periodically ask a few honest questions. Does anyone actually compare payments against contracted rates, or does the team simply assume payments are correct because they arrive on schedule? Is there a documented process for appealing underpayments within the insurer’s deadline? Has the practice reviewed its payer contracts in the last two to three years to confirm rates still reflect current market standards?
If the honest answer to any of these is “not really,” there’s a good chance money is being left on the table right now, quietly, without anyone noticing.
Moving Forward with Confidence
Underpayment is one of the least visible problems in behavioral health billing, precisely because it doesn’t look like a problem. Claims get paid. Deposits show up. Nothing seems broken on the surface. But the gap between what a contract promises and what actually lands in the bank account adds up fast, and by the time most practices notice, appeal deadlines have often already passed.
Building a habit of monthly payment audits, keeping contract rates documented and current, and knowing exactly when and how to appeal can turn this invisible leak into recovered revenue. For practices that don’t have the internal bandwidth to do this consistently, bringing in a billing partner who specializes in behavioral health can close that gap for good.
Frequently Asked Questions
How is underpayment different from a denied claim?
A denied claim is rejected and unpaid entirely. An underpaid claim is processed and paid, but at a lower amount than the contract specifies, which makes it much easier to miss.
How long do I have to appeal an underpaid claim?
It varies by insurer and contract, but most windows fall between 90 and 180 days from the payment date. Some payers allow less, so check your specific contract terms.
Can I bill the client for the difference between the contracted rate and what the insurer paid?
Generally, no. Balance billing rules and provider contracts typically prohibit billing clients for the gap; that difference needs to be pursued through the insurer directly.
How often should I compare payments to my contracted rates?
Monthly reviews are ideal. Waiting until year-end often means missing the appeal window on months-old underpayments.
Do underpayments happen more with certain insurers?
It varies by region and payer, but underpayment patterns often show up when a fee schedule wasn’t updated after a rate renegotiation, which can happen with any insurer.
Is it worth renegotiating contracted rates if I haven’t done it in years?
Yes. Behavioral health reimbursement rates have shifted due to parity enforcement, and practices that haven’t renegotiated recently may be undervalued compared to current market rates.