How to Conduct a Healthcare Underpayment Audit: A Step-by-Step Guide
November 18, 2025
Healthcare underpayments can’t be recovered if they aren’t identified—and for many hospitals, the challenge starts there. Most revenue cycle processes are designed to manage denials, not to evaluate whether paid claims were reimbursed correctly.
A healthcare underpayment audit provides a structured way to identify discrepancies between expected and actual reimbursement. By reviewing paid claims against contract terms, hospitals can uncover revenue that would otherwise remain hidden in zero-balance accounts.
Here's a practical walkthrough of how a rigorous underpayment audit works, from setup through recovery.
What Is a Healthcare Underpayment Audit?
A healthcare underpayment audit is the process of reviewing paid claims to determine whether reimbursement aligns with payer contracts, coding, and clinical expectations.
Unlike denial management, which focuses on unpaid claims, underpayment audits evaluate claims that have already been processed and closed. This makes them essential for identifying revenue leakage that standard workflows miss.
Why Underpayment Audits Are Necessary
Traditional revenue cycle workflows are not designed to detect underpayments.
Most teams focus on:
- open balances
- denial codes
- aging receivables
Underpayments bypass all of these signals. Once a claim reaches zero balance, it typically exits review—even if the reimbursement was incorrect.
Step 1: Define the Scope of the Audit
Before pulling a single claim, establish clear parameters for the review. Scope decisions have a direct impact on both the size of the workable population and the defensibility of any disputes filed. Key parameters to define upfront include:
- Payer types: commercial, Medicare Advantage, Medicaid managed care, or all of the above
- Date range: most payer contracts impose timely filing limits on appeals, so older claims may not be actionable
- Claim types: inpatient, outpatient, specific service lines, or high-acuity DRG categories
- Balance status: zero-balance accounts, open balances, or both
- Minimum thresholds: whether to apply a floor on claim value to focus effort on higher-yield accounts
One note of caution on thresholds: setting the floor too high means missing the cumulative impact of lower-dollar discrepancies. At scale, those add up significantly. Some organizations choose to exclude low-value claims from manual review but still analyze them for patterns.
Step 2: Gather and Normalize Contract and Payment Data
An underpayment audit requires several data inputs working together. The core is the 835/837 transaction data: electronic remittance advice and the original claim submissions. But to evaluate whether a payment was accurate, you also need:
- Executed payer contracts, including all amendments and fee schedules
- Provider manuals specific to each payer and plan
- Historical denial patterns that may indicate recurring adjudication errors
- Previous underpayment audit findings, if any
Data normalization is often the most time-consuming step. Remittance data comes in inconsistent formats, contract terms are written in plain language rather than structured logic, and matching what was paid to what was contractually required takes significant analytical groundwork. Organizations doing this for the first time frequently underestimate how much data preparation precedes actual analysis.
Step 3: Compare Expected vs. Actual Reimbursement
With clean, normalized data, the analysis can begin. Effective identification looks across multiple dimensions simultaneously:
- Contract variance: Does the payment match the rate specified in the contract for this claim type, payer, and service?
- DRG and coding accuracy: Was the claim coded correctly before submission, and did the payer apply the right payment logic based on that coding?
- Payer policy application: Did the payer apply bundling, modifier, or carve-out rules correctly based on current policy?
- Zero-balance review: Do any closed accounts reflect misclassified denials that were adjusted rather than formally denied?
Manual audits typically rely on experienced analysts working account by account. Technology-assisted approaches can evaluate entire claim populations simultaneously, applying rules that reflect known payer behaviors and contract-specific logic. The AMA's 2011 National Health Insurer Report Card documented a 19.3% error rate in commercial claims processing — which suggests the population worth examining is far larger than most manual audits can address.
Step 4: Validate and Prioritize Findings
Not every identified discrepancy is actionable. Some payment variances reflect legitimate adjustments the hospital itself introduced. Others may fall outside appeal filing windows. Still others may be technically recoverable but not worth the effort given their dollar value.
Validation means confirming that the discrepancy reflects an actual payment error, that the claim is within scope, and that the supporting documentation can sustain a dispute if the payer pushes back. Prioritization means ranking validated opportunities by recovery likelihood, financial impact, and payer-specific complexity.
This step is where expertise in payer behavior, not just contract terms, becomes critical. Knowing that a particular payer consistently disputes DRG coding on high-acuity surgical claims, for example, shapes both how you document the dispute and how aggressively you pursue it.
Step 5: File and Track Disputes
Dispute filing varies by payer. Some accept corrected claims. Others require formal reconsideration letters or appeals supported by clinical documentation. For complex cases, payer escalation through peer-to-peer review or contractual dispute resolution may be required.
Regardless of approach, every dispute needs to be tracked through final resolution. That means logging the submission date, tracking response timelines, following up when payers miss deadlines, and confirming that payment actually posts before closing the account. One common failure point is a dispute that technically succeeds in the sense that the payer agrees to reprocess, but the additional payment never actually posts. Tracking disputes through cash confirmation, not just payer agreement, closes that gap.
Step 6: Close the Loop on Prevention
The final step of a good underpayment audit is using findings to reduce future exposure, not just tallying the recovery. Patterns identified during the audit should feed back into:
- Contract renegotiation priorities, particularly for payers with high error rates
- Coding and documentation improvement initiatives
- Billing process corrections that reduce the frequency of specific claim types
- Payer-specific monitoring protocols for the patterns that recurred most often
Organizations that treat each audit as a learning exercise, not just a recovery exercise, progressively narrow their underpayment exposure over time. The first audit often surfaces the most, but it also establishes the baseline for measuring improvement.
How Revecore Supports Underpayment Audits
For health systems that want to run this process continuously rather than periodically, working with a specialized partner provides both the technology to identify opportunities at scale and the operational infrastructure to pursue them efficiently. Revecore's end-to-end underpayment recovery model follows this exact progression, from identification and validation through dispute filing, escalation, and root-cause prevention, designed to convert more of what hospitals are owed into actual cash.
Learn how Revecore helps hospitals recover underpayments at scale.