What is the purpose of Block 31 on the CMS-1500 form?

• A. To indicate the claim is electronically submitted.
• B. To record the provider's contact information.
• C. To verify the claim is correct with the physician's or supplier's signature.
• D. To attach any required consent forms.

Answer: (C)

Block 31 is where the physician or supplier signs to certify the claim’s accuracy. That signature serves as an attestation that the information on the form is correct and that the services billed were provided by the signer or the signer’s organization, confirming that the claim has been reviewed for accuracy before submission. This attestation is what allows payers to process the claim with a reasonable presumption of authenticity. If this signature is missing or missing an electronic equivalent, claims can be delayed or denied because there’s no verification that the claim has been reviewed and authorized by the appropriate provider. The other options don’t fit because block 31 is not about showing electronic submission status, recording contact information, or attaching consent forms; those elements are handled in other parts of the form.