Claim adjustment reason code
Denial code CO-173 meaning
CARC 173, usually seen as CO-173: The service or equipment was not prescribed by a physician.
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- Reason code
- CARC 173
- Short name
- Not prescribed by a physician
- Plain meaning
- The service or equipment was not prescribed by a physician.
- Group codes
- CO-173: Contractual obligation. The provider absorbs the amount under its contract or the payer's rules. Do not bill the patient for it.
Plain-English summary written by Rivvi. X12 owns the CARC list and its exact wording, which is not reproduced here. Read it on the X12 CARC list (list dated November 1, 2025, checked October 23, 2026). This page does not decide how a claim is paid.
Common causes
- The order is missing or not from a qualified prescriber.
What to check before resubmitting
- Get a valid order and resubmit.
Related reason codes
Related pages
Questions
What does denial code CO-173 mean?
The service or equipment was not prescribed by a physician. This is Rivvi's plain-English summary of CARC 173. X12's exact wording is on x12.org.
How do I fix CO-173?
Get a valid order and resubmit.
Can I bill the patient for CO-173?
With group code CO, no. CO means the provider absorbs the amount under its contract or the payer's rules.
Which group codes come with CARC 173?
Most often CO (contractual obligation). The group code, not the reason code, says who owes the amount.
What is the difference between a CARC and a RARC?
A claim adjustment reason code (CARC) says why a claim line was paid differently than billed. A remittance advice remark code (RARC) adds detail, such as which field is missing.