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CO-175 Denial Code: Prescription Is Incomplete

CO-175 means the prescription supporting the claim is incomplete. A prescription exists, but it lacks one or more required elements, such as the item description, quantity, frequency, prescriber signature, NPI, or date.

Quick facts

Code
CO-175 (CARC 175)
Status
Active In use since June 30, 2005; last modified September 30, 2007.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The provider or supplier is responsible until a complete prescription supports the claim. Not billable to the patient.
Official description
Prescription is incomplete.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-175 means

CARC 175 reads simply “Prescription is incomplete.” The payer found a prescription or order, but it doesn’t contain everything the payer requires. Unlike CO-173 (no valid prescription) and CO-174 (prescription after delivery), the problem here is the content of the order.

What counts as complete depends on the payer and the item. DME, supplies, drugs, and vision or hearing items often carry specific order element requirements in payer policies.

Example: an order for diabetic supplies names the item but omits testing frequency. Without frequency, the payer cannot confirm the quantity dispensed is reasonable, and denies the claim with CO-175 and remark N668.

Common causes

  • Missing quantity, frequency, or length of need.
  • Missing or illegible prescriber signature, or a signature type the payer doesn’t accept.
  • No order date or no prescriber NPI.
  • Generic item descriptions that don’t identify what was dispensed.
  • Refill or renewal orders missing elements carried on the original.
  • Templates or forms from referral sources that omit payer-required fields.

How to fix it

  1. Check the order against the payer’s element list for the item or service.
  2. Request a signed, dated addendum or new order from the prescriber that supplies the missing elements.
  3. Appeal or request reopening with the completed order, if the denial came from a records review.
  4. If claim data was missing (such as ordering NPI in box 17b or quantity in box 24G), send a corrected claim with resubmission code 7.
  5. If the order cannot be completed, write off the CO amount.

How to prevent it

  • Use a standard order form that lists every required element for each item category.
  • Review orders at intake before dispensing or scheduling, with a checklist.
  • Accept electronic orders that enforce required fields where possible.
  • Educate referring offices on your payer mix’s requirements.
  • Track CO-175 by referral source to find recurring order gaps. For documentation denials more broadly, see preventable causes of claim denials.

Specialty notes

DME and supply companies, pharmacies, and optical and hearing aid dispensers see this code most, since their payment depends directly on a detailed prescription.

Remark codes that may appear with CO-175

  • N668 (Incomplete/invalid prescription.): The prescription is incomplete or invalid.
  • N378 (Missing/incomplete/invalid prescription quantity.): The prescription quantity is missing or invalid.
  • N31 (Missing/incomplete/invalid prescribing provider identifier.): The prescribing provider's identifier is missing or invalid.
  • N57 (Missing/incomplete/invalid prescribing date.): The prescribing date is missing or invalid.
  • CO-173 (Service/equipment was not prescribed by a physician.): No prescription at all from an eligible prescriber.
  • CO-174 (Service was not prescribed prior to delivery.): The prescription was written after delivery.
  • CO-16 (Claim/service lacks information or has submission/billing error(s).): Missing or invalid claim information, as opposed to a deficient order.

CO-175 FAQ

What makes a prescription complete?

Requirements vary by payer and item, but typically include patient name, date of order, item or service description, quantity and frequency or length of need, prescriber name and NPI, and the prescriber's signature.

Can the prescriber add missing elements later?

Often yes, through a signed and dated addendum or a new order, depending on the payer's rules. Do not alter the original document or backdate additions.

Should I resubmit or appeal after CO-175?

If the claim was denied on records review, appeal with the completed or amended order. If the claim itself left out order data, send a corrected claim. Follow the payer's instructions.

Is an electronic signature acceptable on a prescription?

Many payers accept compliant electronic signatures, but rules on signature types differ. Check the payer's signature requirements, and avoid stamped signatures, which are commonly not accepted.