What is a corrected claim?

A corrected claim is a second attempt at a claim you already sent, going out with the fix applied and marked so the payer knows to replace the original rather than treat it as new.

That marking matters. If you simply resend an identical claim without flagging it as a replacement, the payer sees the same claim twice and denies it as a duplicate, code CO-18. Two denials instead of one.

There is one big exception, and it is the most common resubmission mistake in billing: original Medicare professional claims do NOT take a replacement flag. They go back as a fresh original. You do not have to remember which is which, because the system picks the right form for the payer.

The important idea is that a claim can be sent more than once, and every send is kept:

• Each attempt records exactly what went out, and when.
• The first submission stays visible, labelled as the first, next to the correction.
• Nothing in the claim’s history is ever erased. A correction is a new line, never an edit.

That history is what lets you answer the question a payer or an auditor eventually asks: what did you send, when did you send it, and what changed?

Use a corrected claim when the underlying facts were wrong or incomplete: a missing field, the wrong coverage, a wrong code or modifier. Use an appeal instead when the facts were right and you are arguing with the payer’s decision, with documentation attached.

See A claim came back denied. What do I do? for choosing between the two.