Every practice writes off balances. Some write-offs are contractually required. Others are money you earned and should have collected but didn’t. Knowing which is which, and what typical numbers look like, is the first step toward stopping the preventable ones.
Two types of write-offs, two very different problems
The distinction matters because the right response to each is completely different.
Contractual adjustments
These are amounts you agreed to forfeit when you signed your payer contracts. The classic example is a CO-45 adjustment: you billed $200, the contracted rate is $120, you write off the $80 difference. This is expected, correct, and not a problem. CO-45 adjustments typically make up the largest share of write-offs in any practice, which can make the total write-off figure look alarming when most of it is actually routine.
The key is to verify the allowed amount actually matches your contract. A CO-45 that writes off more than the contractual difference is a hidden underpayment, not a routine adjustment.
Avoidable write-offs
These are the ones that represent real revenue loss: small-dollar denials that were never appealed, balances written off as “uncollectible” without verification, claims that aged past the payer’s appeal window before anyone worked them, and silent denials inside paid claims that never entered a work queue at all.
These don’t show up labeled “avoidable.” They get coded into bad debt or lumped into the contractual write-off bucket, which is exactly why the total write-off figure tells you less than you need to know.
Benchmarks worth tracking
The numbers below are drawn from commonly cited industry figures across RCM literature and benchmark surveys. Actual ranges vary by specialty, payer mix, and claim volume, so treat these as directional targets rather than hard thresholds.
- Denial rate: commonly benchmarked at 5 to 8% of claims submitted for well-run practices. Above 10% consistently signals a coding, eligibility, or authorization issue that is driving volume write-offs.
- Clean claim rate: the share of claims accepted on first submission. The common target is 90% or higher. Below that, rework costs accumulate fast.
- Avoidable write-offs as a share of gross charges: commonly cited at 1 to 3% for high-performing practices. Above 3% is often a sign that small denials are being written off systematically rather than worked.
- Days in accounts receivable (AR): 30 to 40 days is a widely cited benchmark for commercial payers. Claims sitting beyond 90 days often end up as write-offs simply because the payer’s appeal window expires.
- First-pass resolution rate: the portion of denials resolved on the first appeal attempt. Above 80% is generally considered strong.
Where small-dollar write-offs accumulate
The most common source of avoidable write-offs is claims in the $20 to $100 range that were denied and never appealed. The math is simple: if it costs $25 to $50 in staff time to manually work a denial (a figure that appears consistently in RCM cost analyses), writing off a $40 claim is the rational decision for a manual workflow.
That rational decision, repeated across hundreds of claims per month, compounds into a real revenue problem. A practice with 500 denials per month in the sub-$100 range writing off at an average of $60 each loses $30,000 per month on claims that were arguably recoverable. The issue isn’t individual claim economics; it’s the aggregate.
See the guide on appealing sub-$100 claims profitably for the mechanics of bringing the per-claim cost down through templates, batching, and automation.
How to audit your own write-offs
Pull your write-offs from the last 90 days and sort them by adjustment code. Anything labeled CO-45 where the allowed amount matches your contracted rate is routine. Everything else warrants a second look:
- CO-45 where allowed is below contracted rate: dispute as an underpayment, not a denial.
- CO-97 and CO-4 write-offs: check if a modifier or documentation fix would have made these appealable. If so, it’s a process failure upstream.
- Balances written off as “bad debt” under $100: compare to the denial reason. Many of these are recoverable denials, not genuinely uncollectible accounts.
- Claims written off past 180 days: confirm whether the payer’s appeal window was already closed. If it was still open at write-off, that’s a workflow timing issue.
Texas practices: late-payment interest adds up too
For Texas medical practices billing state-regulated commercial plans, write-offs are only part of the revenue picture. Claims paid late (outside the statutory prompt-pay window) may carry interest under Texas Insurance Code Chapters 843 and 1301. A write-off audit is a good time to also check whether any of the claims being written off were paid late and should have carried interest. The guide on 18% interest on late Texas claims covers how to calculate and claim it.
What to do with the numbers
Benchmark comparisons are most useful as a diagnostic starting point. If your avoidable write-off rate sits at 5% of gross charges, the question to answer is whether the cause is denial volume, small-dollar economics, aging, or a combination. Each has a different fix, and the fix has to be economically viable for the claim sizes you’re seeing.
The broader framing is in the revenue leakage guide: write-offs are where leakage becomes permanent. Everything before a write-off is still recoverable.