835 Denial Combination
CO-29+N380
Contractual Obligation · Claim-Level Adjustment
Timely FilingWhat This Combination Means
This combination indicates a timely filing denial where the payer has previously processed an original version of this claim. The payer is instructing you to submit a corrected claim rather than treating this as a final write-off, suggesting the timely filing issue may be correctable if the original claim was filed timely and this is addressing errors from that submission.
Financial Responsibility
provider writeoff
The provider must write off the denied amount per contractual obligation. If a corrected claim is successfully processed, the write-off may be reversed, but the current adjustment requires write-off.
N/A
Appeal Success
30-60 days (appeal or corrected claim process)
Avg. Resolution
Hard
Difficulty
No
Appealable
Step-by-Step Resolution
Steps tailored specifically to this CO-29+N380 combination — not generic advice.
- 1
Verify original claim submission date against payer's timely filing limits
Confirm whether the original claim referenced by N380 was filed within the contracted timely filing window using claim tracking reports or clearinghouse confirmation.
- 2
Determine if this is a corrected claim scenario or true timely filing violation
If the original claim was timely and this denial resulted from a correction attempt filed late, prepare appeal with proof of original timely filing date.
- 3
Submit appeal with proof of timely filing or file corrected claim with timely filing documentation attached
Include clearinghouse transmission reports, certified mail receipts, or payer acknowledgment showing original claim was filed within timely filing limits.
Specialty Context
How CO-29+N380 typically presents across different practice types.
Dental
Dental claims often have shorter timely filing limits (90-180 days). Verify whether orthodontic or multi-visit treatment plans had an original claim processed timely before subsequent corrections were submitted.
Medical
Common with corrected claims for surgical procedures or hospital stays where initial claim was timely but billing corrections (modifier changes, coding updates) were submitted after timely filing expired.
Behavioral Health
Frequent with ongoing therapy claims where an original authorization-linked claim was processed timely, but corrected claims for session count or diagnosis updates were filed beyond timely filing limits.
Individual Code References
View the standalone definition for each code in this combination.
Medicare Contractor Guidance for CARC 29
Noridian + uhc + aetna + bcbs_azThe time limit for filing has expired. Claims must be filed within one year of the date of service. If an act of nature, such as a flood, fire, or there are other circumstances outside of the supplier's control, you can appeal the timely filing, by providing this explanation.
How to Prevent CARC 29 Denials
- ✓
Review the date of service prior to submitting the claim. All claims must be filed within one year of the date of service.
- ✓
Reopenings must be submitted one year from initial determination date or after one year from receipt date due to overpayment via clerical error omissions
Need to resolve this denial?
Get a complete resolution plan with appeal guidance for this exact combination in seconds.
Generate a free resolution plan & appeal letter →Synthesized from official definitions — not from training data