Timely filing limits: why old claims get denied and how to protect your revenue

Timely filing limits are deadlines for getting a claim to the payer. Miss one and the payer can deny the claim with CO-29, even if the care was valid and documented. For most practices, those denials are pure write-offs.

How long you have

Deadlines vary by payer and by your contract:

• Medicare: 12 months from the date of service.
• Medicaid: set by each state, and managed Medicaid plans may have their own limits.
• Commercial payers: set in your contract, often somewhere between 90 days and a year. Some are as short as 90 days.

Corrected claims and appeals usually have their own separate deadlines, often shorter than the original filing limit.

Why claims miss the deadline

• Rejections nobody saw. A claim rejected at the clearinghouse never reached the payer, so the clock kept running.
• Billing the wrong payer first, then running out of time to bill the right one.
• Waiting on documentation, such as unsigned notes, before billing.
• Staff turnover or vacations, leaving a backlog of unbilled visits.

Can a CO-29 denial be overturned?

Sometimes. If you submitted the claim on time and the payer lost it or rejected it in error, you can appeal with proof of timely filing, such as a clearinghouse acceptance report showing the original submission date. Without proof, it’s usually a write-off.

How to protect your revenue

• Work the clearinghouse rejection report every day.
• Keep a list of each payer’s filing and appeal limits.
• Review unpaid claims weekly, starting with the ones closest to their deadline.
• Save clearinghouse acceptance reports as proof of submission.
• Verify eligibility before the visit, so the first claim goes to the right payer.

Related: Denials & old claims · Denial code lookup