Block 11 requires the entry of which important information?

Block 11 on the CMS-1500 form is used to capture crucial information regarding the insured's health insurance coverage, specifically related to group health plan coverage or Federal Employees' Compensation Act (FECA) number. This data is vital for the claims processing, as it helps insurers determine the type of coverage and eligibility for benefits under the involved policies. Accurately indicating group health plan coverage allows for efficient coordination of benefits among multiple carriers when necessary.

In contrast, while the insured's birth date, employer's name, and Medigap policy number have their own importance in the context of insurance claims, they are not specifically required in Block 11 on the CMS-1500. Each block on the form serves a defined purpose, and understanding the specific content required in each block is essential for properly completing the form and ensuring a smooth claims process.