How to find and recover insurance underpayments

How to find insurance underpayments: the short answer

To find insurance underpayments, load each payer’s contracted fee schedule into your billing system, then compare the allowed amount on every remittance against the amount your contract says that payer should allow for that code. Any claim where the payer allowed less than the contract rate is a possible underpayment. Group the differences by payer and code to find patterns, then appeal or dispute them within the deadline in your contract.

The key point is that you can’t spot an underpayment without knowing what you should have been paid. If your contracted rates aren’t in your system, every payment looks correct.

What counts as an underpayment

An underpayment is any payment below what the payer agreed to pay under your contract, or below what the payer’s own published policy says. It is different from a patient responsibility amount. If the payer correctly applies a deductible or coinsurance, the payer’s share is lower, but the allowed amount should still match your contract.

This is why the allowed amount matters more than the paid amount. The paid amount changes with each patient’s benefits. The allowed amount, for an in-network contract, should be the same for the same code and the same circumstances.

Common causes of underpayments

• Fee schedule not updated. The payer is still paying an old rate after a contract renewal or an annual increase that was supposed to take effect.
• Wrong fee schedule applied. The claim is priced under a different product, network or location than the one your contract covers.
• Multiple procedure reductions applied incorrectly. A reduction for a second procedure is applied to the wrong line, or applied when it shouldn’t be.
• Modifier handling. A payer reduces a service billed with a modifier more than the contract allows, or ignores a modifier that should change the rate.
• Provider or location loading errors. A new provider or office is loaded in the payer system with the wrong specialty, taxonomy or location, so claims price at a lower rate. Our guide to credentialing new providers covers how these setup problems start.
• Bundling the contract doesn’t allow. The payer bundles services under its own edits in a way your contract doesn’t support.
• Payer system errors. Sometimes a payer simply makes a mistake, and it repeats on every claim until someone notices.

Step 1: Load your contracted fee schedules

Gather your current contracts and fee schedules for every payer you bill regularly. Many contracts set rates as a percentage of the Medicare fee schedule, or attach a schedule for your most billed codes. If you don’t have a copy of a current schedule, ask the payer or your provider representative for it.

Load the expected allowed amount for each code into your practice management system or a separate contract management tool. Start with your highest volume codes and your largest payers. That covers most of your revenue with a fraction of the effort.

Keep the schedules current. Note every renewal date and rate change, because a contract increase only helps if someone checks that the payer actually applies it.

Step 2: Compare remittances against expected amounts

Every electronic remittance (the 835 ERA) shows the allowed amount for each line. With your fee schedules loaded, your system or reports can flag every line where the allowed amount is lower than expected.

Review those flags regularly, not once a year. A useful report shows, for each payer and code:

• The expected allowed amount.
• The actual allowed amount.
• The difference per claim and the total difference over the period.
• The adjustment reason codes the payer used.

Adjustment codes help explain what happened. Our article on claim denial codes explains how to read them, including the contractual adjustment codes that often appear on underpaid lines.

Step 3: Look for patterns, not just single claims

One underpaid claim might be worth a little. The same error repeated on every claim for a common code, for months, can be worth a lot. Sort your underpayments by payer, code, provider and location. Patterns usually point to a single root cause, such as an outdated fee schedule or a provider loaded under the wrong specialty.

Fixing the root cause with the payer stops future underpayments. Recovering the past ones is a separate step.

Step 4: Dispute and appeal underpaid claims

1. Check the contract terms. Find the section that sets payment rates and the section that covers payment disputes, including how and when to raise them.
2. Contact the payer. For a single claim, a call or a reprocessing request through the payer portal may be enough. Note the reference number and the date.
3. Submit a written dispute or appeal. For anything that isn’t fixed quickly, send a written payment dispute with the claim, the remittance, the relevant contract page or fee schedule, and the calculation of what should have been paid.
4. Escalate patterns to your provider representative. If the same error affects many claims, ask the payer to correct the setup and reprocess the affected claims as a project, rather than appealing each one separately.
5. Track every dispute to a result. Follow up on a schedule and record the outcome against each claim.

Deadlines for underpayment disputes

Deadlines for disputing an underpayment vary by payer and by contract. Some contracts set a specific window from the date of the remittance, and some state laws also set rules for payment disputes and prompt payment. Government payers have their own appeal timelines. Check your contracts and payer manuals, and note the deadline for each payer. An underpayment you find after the deadline may no longer be recoverable.

Also watch for contract terms that let a payer recover overpayments from you over a long period while giving you a much shorter window to dispute underpayments. That imbalance is worth raising at your next contract renewal.

Prevent underpayments going forward

• Keep every payer’s fee schedule loaded and current.
• Flag underpaid lines automatically at payment posting, not months later.
• Check payments the first month after every contract change or rate increase.
• Verify how each new provider and location is loaded with each payer.
• Review underpayment totals by payer every month.

Automating the comparison is one of the most useful things billing software can do, because it turns a manual spot check into a daily safety net. Our billing automation work includes underpayment flags built into payment posting.

See what your payers have underpaid

Most practices have never compared their remittances against their contracts line by line. Request your free A/R audit and we’ll look for underpayment patterns in your recent claims alongside denials and aging A/R. You keep the findings whether or not you work with us.