Final answer:
Active duty members and their family members do not pay any enrollment fee for TRICARE Prime, which is a health care plan for military personnel and their dependents.
Step-by-step explanation:
Active duty members and their family members pay no fee for TRICARE Prime enrollment. This health care plan is specifically designed for service members, retirees, and their families, offering them comprehensive coverage for a variety of healthcare services. Active duty and their families enjoy this benefit without an enrollment fee as part of the military healthcare system. However, cost-shares for particular services and medications may apply, and these are generally minimal.