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N28 Remark Code: Consent Form Requirements Not Met

N28 means the consent form requirements for the service were not fulfilled. The payer found a problem with how or when consent was obtained, such as timing, required signatures, or form content, so it will not pay the service as billed.

Quick facts

Code
N28 (RARC N28)
Status
Active In use since January 1, 2000.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The denial is assigned to the provider. Payers and program rules often prohibit billing the patient for a service denied over consent requirements.
  • PI (Payer Initiated Reduction): A payer-initiated adjustment, common with Medicaid programs that enforce federal consent rules.
Official description
Consent form requirements not fulfilled.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What N28 means

N28 is different from a simple missing-paperwork denial. The payer has consent documentation, or knows consent was obtained, but the process did not satisfy the rules that apply to the service. Typical defects involve timing (consent signed too close to the procedure or after it), who signed (patient, interpreter, witness, or the person obtaining consent), or what the form says (an outdated version or missing required statements).

It generally accompanies CARC 16, CARC 251 (deficient documentation), or CARC 272 (program guidelines not met).

Common causes

  • The required waiting period between consent and procedure was not observed, and no qualifying exception was documented.
  • The patient did not meet an eligibility requirement, such as a minimum age, at the time of consent.
  • A required signature or date was missing, for example the physician’s statement or an interpreter’s attestation.
  • An old or unapproved version of the consent form was used.
  • The date of the procedure on the form does not match the claim.

What to do

  1. Get the payer’s specific finding so you know which requirement failed.
  2. Compare the form to the rule. Check dates, ages, signatures, and form version against the payer’s or program’s instructions.
  3. Correct genuine clerical errors if the payer allows amendments, then resubmit with the corrected form.
  4. Appeal if you believe the form did satisfy the rule, pointing to the relevant sections.
  5. Accept the denial when the requirement truly was not met. Do not transfer the charge to the patient if the rules prohibit it.

How to prevent it

Build a checklist for each consent-regulated procedure that covers the form version, patient age, waiting period, and every signature. Have scheduling confirm the consent date before booking the procedure, and have billing review the form before the claim is released.

Codes that may appear with N28

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim has a submission or billing problem; N28 narrows it to consent requirements.
  • CO-251 (The attachment/other documentation that was received was incomplete or deficient.): The documentation received was incomplete or deficient.
  • CO-272 (Coverage/program guidelines were not met.): Coverage or program guidelines, including consent rules, were not met.
  • N3 (Missing consent form.): The consent form is missing altogether, rather than failing the requirements.
  • N228 (Incomplete/invalid consent form.): The consent form itself is incomplete or invalid.
  • N399 (Incomplete/invalid elective consent form.): An elective consent form is incomplete or invalid.

N28 FAQ

Can the patient sign a new form to fix N28?

Often not. When the rule is about when consent was given relative to the procedure, a form signed afterward cannot satisfy it. Clerical errors on a form signed in time may be correctable, depending on the payer.

Which services have strict consent requirements?

Sterilization under Medicaid is the best-known example, with federal rules on the patient's age, the waiting period, and the form's content. Some payers and states add rules for other procedures.

Can I bill the patient after an N28 denial?

Usually not. Medicaid rules and many contracts bar billing the patient for services denied for the provider's failure to meet consent requirements. Check the payer's rules.