What is required for Block 31 to be considered complete?

For Block 31 on the CMS-1500 form to be considered complete, it is essential to include the provider's signature. This signature verifies that the physician or provider has reviewed the information on the claim and certifies that the services billed were medically necessary. The presence of the provider's signature indicates accountability and compliance with regulations regarding the submission of claims.

Including a timestamp, the NPI of the facility, or diagnosis codes may be relevant for other parts of the form or may contribute to other administrative requirements, but they do not fulfill the specific requirement of Block 31. Therefore, the primary focus here is the signature, as it acts as a critical validation for the services rendered.