Final answer:
Medicare provides services primarily for those over 65 while Medicaid focuses on those with very low incomes. HMOs offer an alternative pre-paid health plan model.
Step-by-step explanation:
The resource that provides services to assist with various federal health insurance program benefits is Medicare, which offers insurance primarily to people over sixty-five years old. Medicaid is another public healthcare system that provides health services to people with very low incomes who meet other eligibility requirements. Alternatives to these public programs include Health Maintenance Organizations (HMOs), which are pre-paid health plans providing care through designated providers. Each of these resources has a specific focus and serves different population segments based on age, income, or military service.