The Medical Information Bureau consists of members from which group?

The Medical Information Bureau (MIB) is primarily composed of member insurance companies. This organization acts as a clearinghouse for medical and health-related information that can be used by insurance companies during the underwriting process. The MIB collects data about applicants' medical histories and other relevant health information to help insurers assess risk more accurately.

Insurance companies use this shared information to identify potential risks among applicants, which helps in making decisions regarding policy issuance and premium rates. The collaboration among insurance providers in the MIB allows for a more standardized assessment of medical information, ultimately benefiting the underwriting process.

The other groups listed do not play a direct role in the MIB's structure or function. Healthcare providers may supply medical information but are not members of the bureau. Government agencies are not involved in the operational aspects of the MIB, and policyholders, while they’re the recipients of the insurance services, do not have a role in its membership or management.