CO-253 denial code
Sequestration. A federal budget-law reduction — 2% off Medicare's payment — applied after everything else is calculated. It is not a denial, not appealable, and not the patient's problem. It is an Act of Congress, literally.
CO — Contractual Obligation. The write-off is yours. You agreed to it in your contract with the payer, and you cannot bill the patient for it.
Why you got it
- 1Federal sequestration applied to Medicare fee-for-service payments.
- 2A Medicare Advantage plan passing the same reduction through, where the contract allows it.
How do I fix a CO-253 denial?
- Post it as the contractual adjustment it is. There is nothing to correct, resubmit, or appeal.
- Make sure your posting rules never shift this amount to the patient. It comes off the payer's 80%, not the beneficiary's share.
- If the amount isn't roughly 2% of the Medicare payment, something else is on the line — read the other codes.
How to stop the next one
Nothing to prevent — build it into expected reimbursement so month-end doesn't keep rediscovering it. When your Medicare payments all arrive 2% light, this is why.
Our diagnosis scrubber will not catch this one. CO-253 is driven by procedure codes, modifiers, or eligibility rather than by the diagnosis set — and procedure-side checking needs CPT codes, which aren’t included yet. We would rather tell you that than sell you a tool that quietly misses your most common denial.
If denials like this are a volume problem rather than a one-off, the denial management page explains how the paid workspace catches the coding causes on every claim, and the free ICD-10-CM lookup shows the coding notes behind any diagnosis code on the remittance.