RARC M62: Missing or Invalid Attending Provider Information

What Does RARC M62 Mean?

M62 indicates that the payer cannot process the institutional claim because the attending provider's information is absent, incomplete, or does not pass validation. The attending provider is the physician primarily responsible for the patient's care during the facility encounter, and their identification is required on UB-04 claims (form locator 76). This data element serves multiple purposes: it helps the payer verify that the provider is enrolled, it ties the facility claim to the responsible clinician, and it supports medical review and audit processes.

The most common cause of M62 is a missing or incorrect NPI in the attending provider field. This can happen when the field is left blank because the attending physician was not assigned at the time of billing, when the NPI entered belongs to a different provider (such as the admitting physician rather than the attending), or when the NPI is valid but the provider is not enrolled with the payer. For Medicare claims, the attending provider must have an active Medicare enrollment — an NPI alone is not sufficient if the provider has opted out or their enrollment has lapsed.

M62 typically pairs with CARC 16 (missing information) or CARC 4 (inconsistency). On inpatient claims, the attending provider field is especially critical because the payer may use it to route the claim for clinical review or to verify compliance with supervision requirements.

What to Do

Verify the attending provider's NPI using the NPPES registry and confirm they are enrolled with the payer. For Medicare, check that the provider has active Medicare enrollment and is not in an opted-out status. If the attending provider field was blank, determine the correct attending physician from the medical record and populate the field. If an NPI was entered but rejected, confirm it belongs to the individual provider (not a group or facility NPI) who served as the attending physician for the encounter. Resubmit with corrected information.

For hospitals and facilities, ensure that the attending provider assignment is finalized in the patient accounting system before claims are generated. Some facilities allow claims to be built before the attending physician is confirmed, which leads to blank or default values in this field. Building a validation rule that blocks claim generation when the attending provider NPI is missing can prevent M62 denials across the board.

Common Scenarios

• An inpatient claim is generated before the attending physician is finalized in the hospital's registration system, and the claim goes out with a blank attending provider field.
• A locum tenens physician covers for the regular attending physician, but the locum's NPI is not yet enrolled with Medicare, causing the claim to fail validation with M62.
• A hospital billing system auto-populates the admitting physician's NPI into the attending provider field, but the patient's care was transferred to a different attending physician during the stay.

Commonly Paired With

RARC M62 commonly appears alongside these CARC denial codes: