Denial code

CO 170

This payer does not pay this service when this type of provider performs it.

Usually recoverable CO

What CO 170 means

CO — Contractual obligation — the provider absorbs it and cannot bill the patient.

So the balance cannot move to the patient. Either the appeal recovers it or the practice absorbs it. That makes the appeal decision the whole decision on this line.

Is it worth appealing?

Usually recoverable. Appeal it. The money is usually there.

Why it fires

In the order we see it.

  1. The rendering provider type is not eligible for this service under the payer's policy.

  2. The service met incident-to requirements but was billed directly.

What to do

Check whether the service qualified as incident-to, or should have been billed under a supervising provider the payer recognises.

What actually wins it

The documentation, not the argument.

Documentation supporting incident-to billing, where the requirements were genuinely met on the day.

The common mistake. Do not rebill under a supervising provider unless the incident-to requirements were actually met. That is a compliance exposure, not a workaround.

Where this comes from. This is our own reading of the code, not the payer's and not a copy of the standards text. We classify it from how these denials actually resolve. Where we are unsure, we say so rather than guessing.

Related codes

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