What counts as an underpayment?
An underpayment is a payer payment below the amount expected under the applicable contract, fee schedule and claim facts. It is not simply the difference between the billed charge and the deposit. Contractual adjustments, patient responsibility, coverage and coordination of benefits can explain that gap. A variance starts an investigation; it is not automatically recoverable.
First confirm the service, date, provider, place of service, coding and applicable payer agreement. Then compare the expected payer amount with the actual adjudication for that claim or line.
Read the remittance before changing the balance
The electronic remittance advice (ERA), commonly the X12 835 transaction, explains claim and service-line adjudication. Its group code indicates broad financial responsibility, a claim adjustment reason code (CARC) explains an adjustment, and a remittance advice remark code (RARC) may add detail. Read the codes together with the contract and claim record, not in isolation.
The ERA is the explanation; an electronic funds transfer (EFT) is the money. One payment can cover multiple claims, and provider-level adjustments may affect the total without belonging to one claim. Match the remittance and deposit before treating a low deposit as a short-paid service. See our ERA posting and reconciliation guide.
A repeatable underpayment audit
- Choose a payer, contract, service group and date range; confirm the fee schedule and effective dates.
- Reconcile the ERA to cash, including provider-level adjustments and reversals.
- Calculate the expected payer payment at claim or line level after the applicable adjustments and patient responsibility.
- Compare actual adjudication with that expectation. Check coding, modifiers, coverage, secondary payer and contract terms before classifying a variance.
- Record the claim, amount, reason, evidence, owner and payer-specific correction or appeal deadline in a work queue.
- Follow through to corrected payment or a documented explanation, then reconcile the final ledger entry.
Prioritize approaching deadlines and material repeat patterns. A sample of one service line can expose a fee-schedule mapping issue, but do not project its dollars across the whole practice without checking the remaining claims.
Prevent the same discrepancy from recurring
Group confirmed variances by payer, code, provider and effective date. If a contract load is wrong, correct the expected-amount table; if claim information was wrong, fix the upstream workflow. Track investigated, confirmed, recovered and closed-as-correct amounts separately. This avoids counting every suspected variance as revenue recovered.
Synergy posts payments with a published 99% accuracy target and works denials within 48 hours. If your paid claims have not been checked against expected reimbursement, request a free practice audit. No long-term contract is required.
Frequently asked questions
Is every payment below the billed charge an underpayment?
No. The billed charge is not the contracted allowed amount. Review the payer agreement, adjudication, contractual adjustment and patient responsibility before concluding that the payer paid too little.
Can a low EFT deposit prove a claim was underpaid?
No. A deposit can cover multiple claims, and provider-level adjustments or reversals can change its total. Match the EFT to its ERA, then compare the individual claim's actual payer payment with the contract-based expectation.