What action should be taken regarding Block 11 D?

In this context, Block 11D on the CMS-1500 form is specifically designated for information about other health insurance coverage the patient may have. If there is no other payer or if the patient does not have additional coverage that the provider needs to bill, then it is appropriate to leave this block blank. Leaving Block 11D blank avoids confusion over whether there is an alternate payer to bill or if the information is simply not applicable. Providing incorrect information in this section could lead to issues with processing claims, including delays or denials from insurance companies.

The other choices do not apply to this situation because filling in alternate payer details is only necessary if there is indeed another insurance to consider, including the insured's Social Security number is irrelevant to Block 11D, and writing 'Not Applicable' would still indicate a need for clarification that may not be necessary if the block is simply left blank. Proper completion of the CMS-1500 form is crucial for accurate reimbursement and compliance with insurance billing standards.