Employees covered by group life or health policies must be issued a/an:

In the context of group life or health insurance policies, employees covered under such plans receive a certificate of insurance. This document serves as proof of coverage and outlines the benefits and terms of the insurance provided to them. It is an essential element because it assures employees that they are indeed covered under the group's policy and provides vital information about their specific rights and the extent of the coverage they enjoy.

The certificate of insurance acts as a summary document that reflects the essential details of the policy, including the identity of the policyholder (typically the employer), the amount of coverage, and information on how to file a claim. It is crucial for employees to have this certificate, as it helps them understand their insurance benefits and provides evidence of their coverage when needed.

Other options do not serve the same purpose: an estimate of employer's premiums is for employer use, the master policy is the actual insurance contract held by the employer, and a monthly premium notification pertains to payment information rather than evidence of coverage for employees.