CARC 207 Active

CO-207: Invalid NPI Format

TL;DR

Invalid NPI format. Provider error. Fix the NPI to 10 digits, no letters or dashes, and resubmit.

Action
Resubmit
Who Pays
Provider
Appeal
No
Patient Impact
None
Disclaimer
This content is for informational purposes only and does not constitute professional billing advice. Always verify information against your payer contracts and current coding guidelines. Consult a certified billing specialist for specific claim issues.

What Does CO-207 Mean?

CO-207 assigns the invalid NPI format error to the provider. This is purely a data entry mistake that the provider must correct. The patient cannot be billed for this administrative error. Correct the NPI format and resubmit the claim.

CARC 207 is a straightforward formatting rejection: the National Provider Identifier submitted on the claim does not meet the required 10-digit numeric standard. This is almost always a data entry problem rather than a credentialing issue.

Common formatting errors that trigger this code include NPIs with fewer or more than 10 digits, entries containing dashes, spaces, or alphabetic characters, and fields left blank or partially filled. Some billing systems also trigger this when the NPI field is populated with a legacy identifier (like a UPIN or state license number) instead of the actual NPI.

This is one of the most preventable denial codes in medical billing. Automated NPI validation at the point of data entry — checking that the field contains exactly 10 numeric digits before the claim is submitted — eliminates virtually all CARC 207 denials. The resolution is always the same: find the correct NPI, enter it properly, and resubmit.

Common Causes

Cause Frequency
Incorrectly formatted NPI number The NPI contains missing digits, alphabetic characters, special characters, or dashes/spaces that violate the required 10-digit numeric format Most Common
Missing or incomplete NPI The NPI field is blank, partially filled, or contains fewer than 10 digits on the submitted claim Most Common
Outdated or expired NPI The NPI provided has been deactivated or is no longer valid due to provider status changes or non-renewal Common
NPI not registered with the appropriate authority The NPI was never properly registered with CMS through the NPPES system or has not completed the application process Common
NPI mismatch with the listed provider The NPI on the claim does not correspond to the provider name or practice listed elsewhere on the claim form Common
NPI not recognized by the specific payer The NPI is valid but the payer's system does not accept it because the provider is not credentialed or enrolled with that payer Occasional

How to Resolve

Correct the NPI to the valid 10-digit numeric format and resubmit the claim.

  1. Find the correct NPI Look up the provider's NPI in the NPPES registry and confirm it is a valid 10-digit numeric identifier.
  2. Correct the claim Replace the invalid NPI entry with the correct 10-digit NPI. Remove any non-numeric characters.
  3. Resubmit immediately Resubmit the corrected claim. This is a simple fix that should not require an appeal.
Do Not Appeal This Code

This is a standard contractual adjustment. The amount is a provider write-off per your payer contract and cannot be billed to the patient.

Common RARC Pairings

The RARC code tells you exactly what triggered the CO-207:

RARC Description
N286 Missing/incomplete/invalid provider identifier. Correct the NPI format and resubmit →
N290 Missing/incomplete/invalid rendering provider primary identifier. Ensure rendering provider NPI is valid →

How to Prevent CO-207

General Prevention

Related Denial Codes

CO-13 — Date of Death Precedes Date of Service CO-14 — Date of Birth Follows Date of Service CO-16 — Missing Information or Billing Error CO-31 — Patient Not Identified as Insured CO-107 — Related or Qualifying Service Not Identified

Sources

  1. https://www.mdclarity.com/denial-code/207
  2. https://x12.org/codes/claim-adjustment-reason-codes
  3. Codes maintained by X12. Visit x12.org for official definitions.