How We Recovered $285K in Infusion Underpayments and Improved Collections

An underpayment differs fundamentally from a denial or a missed charge. A denial is a claim the payer actively rejected after review. A missed charge is a service that was never billed at all. An underpayment is a claim the payer accepted and paid. The payment simply came in below the contracted rate agreed upon. Spotting this gap is uniquely difficult since the claim looks closed. Nothing prompts a second look unless payment is actively compared. This is exactly the blind spot Underpayment Recovery work is designed to close.

At Infusion Billing Services, we recently completed a full audit for a client. Their practice had strong collections on paper but was still losing revenue. This case study explains five specific Underpayment Recovery categories we found. Together, these gaps had cost the practice $285,000 over one year.

Client Snapshot

Our client was a mid sized infusion practice with three locations. They submitted roughly 1,050 claims per month across contracted payers. Commercial payer contracts made up close to 55% of total claim volume. Medicare and Medicare Advantage accounted for most of the remaining share. We conducted a full twelve month Underpayment Recovery audit across all contracts. This went well beyond the practice’s standard collections reporting process. Standard reports had shown collections at 94% of billed charges. The full Underpayment Recovery audit revealed $285,000 hidden within that figure.

Underpayment Category 1: Drug Reimbursement Paid Below the Contracted ASP Rate

High cost infused drugs are typically reimbursed at a contracted percentage. This percentage is based on the average sales price for that drug. Several claims were paid below this contracted ASP rate, the most common finding across the entire Underpayment Recovery audit. Payer system errors applying an outdated fee schedule often caused this gap.

Problem:

• Drug claims were paid below the contracted ASP percentage
• Payer systems applied an outdated fee schedule to payments
• Underpayments went unnoticed since claims appeared fully processed

Fix:

• Built a line by line comparison against contracted ASP rates
• Reviewed every high cost drug claim for rate accuracy
• Flagged and appealed claims paid below the contracted rate

This single fix recovered the largest share of the $285,000 total. It became the clearest example of what Underpayment Recovery can uncover.

Underpayment Category 2: Multiple Units Paid as a Single Unit

Some claims billed multiple units for time based or dosage based codes. Payers sometimes processed these claims as if only one unit applied. This common processing error significantly reduced the total payment received, a pattern that surfaced quickly once Underpayment Recovery review began. The claim still appeared paid, just at a fraction of its value.

Problem:

• Claims billed with multiple units were paid as a single unit
• Payer processing errors affected time and dosage based codes
• Reduced payments were not flagged as underpayments automatically

Fix:

• Flagged claims where paid units did not match billed units
• Reviewed unit discrepancies for manual correction and appeal
• Resubmitted corrected claims reflecting the full unit count

This fix recovered revenue tied directly to a common payer system error. It proved Underpayment Recovery work extends well beyond drug pricing alone.

Underpayment Category 3: Contracted Rate Not Applied Due to Outdated Payer Fee Schedule Loading

Payer systems do not always load new contract terms immediately. Some claims were paid using an old fee schedule as a result, exactly the kind of gap Underpayment Recovery is built to catch. The payer had not yet updated their system with the current contract. This gap persisted quietly until payments were directly cross checked.

Problem:

• Payer system used an outdated fee schedule for payment
• Recently negotiated contract rates had not been loaded yet
• Payments matched the old rate rather than the current one

Fix:

• Cross checked payments against the most current signed contract
• Did not assume the payer’s system reflected accurate terms
• Flagged and appealed claims paid under outdated fee schedules

This fix caught a gap that would have otherwise persisted indefinitely. Fee schedule verification became a standing part of ongoing Underpayment Recovery work.

Underpayment Category 4: Secondary Payer Coordination Shorting the Total Reimbursement

Claims processed through secondary payer coordination follow specific payment rules. Some claims resulted in a combined total below expected reimbursement. This happened when coordination logic reduced payment beyond contracted terms. Neither individual payer’s rate alone would have produced this lower total.

Problem:

• Combined payment from both payers fell below expected reimbursement
• Coordination logic reduced payment beyond contracted terms
• No calculation confirmed the expected total before acceptance

Fix:

• Calculated expected combined reimbursement before claim processing
• Flagged any final payment falling short of that calculated figure
• Appealed coordination related underpayments with both payers

This fix addressed a complex gap most practices never think to check. Underpayment Recovery work in this area requires calculating the expected total in advance, not just reviewing payments after the fact.

Underpayment Category 5: Bundled Payment Applied Where Separate Reimbursement Was Contracted

Some payer systems apply bundled payment logic by default. This happened even when the contract specified separate reimbursement instead, one of the more technical patterns this Underpayment Recovery review uncovered. Certain drug and administration combinations were paid as one bundled rate. This directly contradicted the negotiated terms on file.

Problem:

• Claims were paid as bundled when separate rates were contracted
• Payer system defaulted to bundling logic incorrectly
• Contract terms specifying separate reimbursement were not applied

Fix:

• Reviewed contract language for specific bundling exceptions
• Flagged claims paid under incorrect bundling logic
• Appealed claims that ignored contracted separate reimbursement terms

This fix ensured payments matched what had actually been negotiated. It closed the final category identified during the Underpayment Recovery audit.

How the $285K in Underpayments Was Identified

Standard collections reporting shows claims as paid once payment posts. This Underpayment Recovery audit went further, comparing every paid claim against the contract. Each claim was reviewed line by line against the fee schedule. ASP rate accuracy was checked first across all high cost drugs. Unit counts were then compared between billed and paid amounts. Fee schedule loading dates were cross checked against contract effective dates. Secondary coordination and bundling logic were reviewed as separate categories. This process took ten weeks and became the template for future Underpayment Recovery reviews.

Financial Recovery Results

The table below shows the underpayment breakdown and the improvement achieved. These results reflect what a full Underpayment Recovery audit uncovered across every category identified.

These underpayments never appeared on a standard collections report. Only a dedicated Underpayment Recovery audit surfaced the complete financial picture. This is why the practice now treats it as a standing part of ongoing revenue review, not a one time project. This also confirms why a high collection percentage does not guarantee full payment.

Key Takeaways

These lessons form the foundation of effective Underpayment Recovery work, and they apply to any practice managing contracted payer relationships.

• Compare every paid claim against the contracted ASP rate directly
• Check that paid units match billed units on every claim
• Verify payer fee schedules reflect the most current contract terms
• Calculate expected reimbursement before accepting coordination payments
• Confirm bundling logic matches what the contract actually specifies

Conclusion

Underpayment Recovery addresses revenue that was paid incorrectly, not denied. ASP rates, unit counts, fee schedules, coordination, and bundling all carry risk. As this case shows, a full Underpayment Recovery audit uncovered $285,000 in underpayments. Preventing these gaps going forward protects revenue the practice already earns.

If your practice has never audited payments against your contracts, we can help. Infusion Billing Services conducts full Underpayment Recovery audits beyond standard collections tracking. Hidden underpayments often exceed what a high collection rate suggests.

Contact Infusion Billing Services today for a complete Underpayment Recovery assessment. Start uncovering revenue your practice may not know it is losing.