Health insurance system in the USA

1. Medicare

2. Medicaid

3. Medicare-Medicaid (Medi-Medi) 

4. Medigap (medicare supplemental insurance)

Medicare: it is for people aged more than 65; physically or mentally disabled, with end-stage renal disease, and only certain neurodegenerative diseases (e.g. amyotrophic lateral sclerosis). It has 4 parts: A, B, C, D

part A covers inpatient services

part B covers outpatient services, outpatient surgery, and preventive care.

part C  (medicare advantage): this is provided by private insurance companies and it includes both inpatient and outpatient expenses

PART D covers prescription drugs

Medi-medi includes very low-income seniors, disabled who qualify for both Medicare and Medicaid.

Medigap covers expenses not covered by parts A, B, and D. It covers copays and deductibles.