OA-146: Diagnosis Code Invalid for Date of Service

What Does OA-146 Mean?

OA-146 may appear when the invalid diagnosis code is flagged as an administrative coding issue. The resolution is the same — correct the code and resubmit.

CARC 146 is a coding rejection that fires when the diagnosis code submitted on the claim was not valid on the date the service was provided. ICD-10-CM codes are updated annually, with changes taking effect every October 1. Codes are added, deleted, and revised in each update. If a provider submits a claim using a code that was deleted in a prior update, or a code that was added in a future update and was not yet effective on the service date, the payer will reject it with CARC 146.

The most frequent trigger is outdated codes — a provider's coding software or reference material has not been updated to reflect the latest ICD-10 annual changes, and coders unknowingly select codes that no longer exist. Insufficient specificity is the second most common cause — the payer requires a more granular code (additional characters in ICD-10-CM) and the submitted code is too general for the date of service. Data entry errors (wrong digit, transposed characters) and selecting a code that does not clinically match the service are also frequent causes.

This is one of the most preventable denial codes in medical billing. Annual code set updates are published months in advance, and coding software vendors release updates before the October 1 effective date. Practices that update their coding tools promptly and train coders on changes rarely see CARC 146. Resolution is straightforward — identify the correct code for the service date, update the claim, and resubmit.

How to Resolve

Verify the diagnosis code against the ICD-10-CM code set effective for the date of service, select the correct valid code, and resubmit the claim.

1. Identify the correct code Look up the valid ICD-10-CM code for the service date and verify it matches the clinical documentation.
2. Correct and resubmit Update the diagnosis code on the claim and resubmit.

How to Prevent OA-146

• Keep coding software current with annual ICD-10-CM updates
• Use front-end code validation before claim submission

Also Filed As

The same CARC 146 may appear with different Group Codes:

Related Denial Codes