Negative A/R Is the Liability Nobody Tracks

Every Monday morning, the A/R aging report gets pulled and the green numbers get celebrated. The line item nobody runs a separate report on is the one that's now reportable.

Negative A/R is the credit balance side of the ledger: money owed back to patients and payers because someone overpaid, the contractual allowance was keyed wrong, or a payment double-posted. As of January 1, 2025, what most practices have been treating as a customer service backlog or an accounting cleanup task is a federal compliance exposure with False Claims Act teeth. CMS's December 9, 2024 final rule replaced the old "reasonable diligence" identification standard with the FCA-grade "knowingly receives or retains" standard codified in 42 CFR 401.305. The 60-day clock to report and return now starts at the moment of knowledge, not after the dollars get quantified. A stack of unreviewed credit balances on the aging report is, by the plain text of the updated standard, potentially deliberate ignorance under 31 USC 3729(a)(1)(G), the reverse false claims provision. State enforcement is layering on top: Florida's CS/CS/SB 1808, effective January 1, 2026, mandates a 30-day patient refund and assesses $500 per violation against facilities that miss it.

A clean A/R aging report has always been the headline KPI. It's also one of several practice metrics that look healthy until you read them sideways, and credit-balance exposure is the one that just acquired federal teeth.

Industry benchmarks put credit balances at 1 to 2% of total A/R. HFMA estimates a small-to-mid hospital generates approximately $2 million in credit balances per year. The dermatology equivalent isn't published anywhere, but the ratio scales: a 5-provider derm practice doing $4-5M in annual collections would carry roughly $40K-$100K in credit balances at any given time.

Over 55% of credit balances trace back to incorrect contractual-allowance posting at the time of payment, not to patients overpaying or payers double-paying. Most credit balances are accounting artifacts: the allowance got keyed wrong against the contract at the moment of payment posting. Nobody underpaid anyone, the system just recorded it that way. The exposure is the same either way under the rule.

Practices tend to rationalize credit balances by category. The "real" credits, where a patient overpaid a copay or a secondary payer reimbursed late, get refunded fastest because someone calls and asks for the money back. The phantom credits from posting errors accumulate quietly because no one is calling about them. They look like clerical noise, and the pattern of small posting issues compounding into large untracked exposure is the same workflow failure that surfaces in other A/R reads.

The CMS final rule does not distinguish between those two categories. Both look identical to a qui tam plaintiff's firm running a pattern match against an A/R aging report. Both trigger the 60-day clock the moment the practice acquires knowledge that something on the negative side of the ledger needs investigation. The 180-day investigation safe harbor in the final rule lets the practice extend the clock to investigate related overpayments from the same root cause, but the original 60-day deadline still applies once the investigation completes.

The enforcement curve is climbing in line with the broader pattern of OIG and DOJ enforcement reaching into practice-level billing. Mount Sinai/Continuum paid $2.95 million in 2016 in Kane v. Healthfirst, the foundational FCA case under the 60-day rule: roughly 900 improperly billed claims traced to a software-glitch root cause, a $590K relator share, and a four-day retaliation window before the whistleblower was fired. Every later 60-day rule case cites it. DOJ recovered $5.7 billion from healthcare matters in FY2025, the most ever, with 1,297 qui tam suits filed across all sectors. Recent settlements include $29 million for a New York health system that retained inflated DoD payments and $4.2 million for a hospice company that retained Medicare hospice overpayments.

Qui tam plaintiffs' firms run pattern analysis on public billing data and look for two things: visible credit-balance exposure, and no documented investigation timeline. The dollar amounts at a 5-provider derm practice are smaller than a hospital system's, but the legal framework is the same: a $40K-$100K unaddressed credit-balance backlog triggers the same FCA exposure as a $2M one. Filing cost is the same either way, and the targeting math no longer favors scale.

Clarity RCM manages revenue cycle for 200+ dermatology practices across 42 states. It's all we do. See how we work.