1. MediCare是为65岁以上的老人的,有条件才可申请的: you are eligible for Medicare if you or your spouse worked for at least 10 years in Medicare-covered employment and you are 65 years or older and a citizen or permanent resident of the United States. If you aren’t yet 65, you might also qualify for coverage if you have a disability or with End-Stage Renal disease (permanent kidney failure requiring dialysis or transplant)

2. 为低收入人士设的是MediCaid

3. 现在光有绿卡不能申请MediCaid了: Effective July 1, 2006, Public Law No. 109-171 Deficit Reduction Act of 2005 Section 6036, as amended by Public Law No. 109-432 Tax Relief and Health Care Act of 2006, requires individuals to provide satisfactory documentary evidence of citizenship or nationality when initially applying for Medicaid or upon a recipient’s first Medicaid re-determination

不知道私家保险的情况。政府保险有两种 - Medicare and Medicaid.

Medicare 是联邦保险，须65+，>=40 SS Credits.
Medicaid 是联邦和州共同拨款，各州运营，针对低收入和一些特殊人群。具体政策要看你在的州。很多州不提供给入美5年内的移民。加州没有5年限制，所以我给父母都办理了Medi-Cal （Califronia version of Medicaid)