CO-45 Denial Code: Charge exceeds fee schedule/contracted arrangement
Usually NOT a denial — it's the routine contractual write-off between your charge and the contracted rate. The hidden problem: payers sometimes 'adjust' below the actual contracted rate, and almost nobody checks.
Why it happens
- Normal contractual adjustment (expected, not recoverable)
- Paid amount below your actual contracted rate — an underpayment hiding inside a routine code
- Payer applied the wrong fee schedule (old year, wrong region, wrong product line)
- Multiple-procedure reduction applied incorrectly
How to fix it, step by step
- Spot-check paid amounts against your contract's fee schedule for your top 20 CPTs
- Where paid < contracted: send an underpayment demand citing the contract rate and claim details
- Ask the payer in writing which fee schedule was applied when numbers look wrong
- Track by payer — systematic underpayment is a pattern worth escalating (state prompt-pay rules may add interest)
Is it worth working?
The write-off portion: zero. The underpayment portion: real money that compounds — practices that never audit CO-45 lines never find it.
The write-off portion: zero. The underpayment portion: real money that compounds — practices that never audit CO-45 lines never find it.
How much is your practice writing off to denials like this?
Send 6 months of remittance files (3 clicks in your billing software) — get a free one-page scorecard of your denied dollars, what's recoverable, and your top payer patterns — within one business day of receiving your files. Recovery is contingency-only: no fee unless money posts.
Get the free denial auditMore codes: the Claimmender denial-code library.