又查了点资料，移民局的I-864P Poverty Guidelines 指出

新移民不可享受means-tested public benefits,而且列举了有关的联邦means-tested public benefits，目前这些福利包括 food stamps, medicaid, supplement security incomes(SSI), temporary assistance for needy families(TANF),and the state child health insurance program(SCHIP).而且特别指出哪些救助不属于means-tested public benefits。另外，I-864P还指出各州可能还有一些规定。大家需要查找自己所在州的情况。
可以看到，medicare 不属于means-tested public benefits。可是medicare 有申请要求。作为外国人，必须在美国住满 5 年。看来，父母移民后的前 5 年是个问题。

下面是移民局I-864P 表网址，有兴趣可看看。
http://www.uscis.gov/portal/site/uscis/menuitem.5af9bb95919f35e66f614176543f6d1a/?vgnextoid=73c63591ec04d010VgnVCM10000048f3d6a1RCRD&vgnextchannel=db029c7755cb9010VgnVCM10000045f3d6a1RCRD

所有跟帖： 

• To be qualified for medicare, you need to be at least 65 year ol -dreamroamer- ♂ (584 bytes) () 03/05/2010 postreply 07:42:40

• But after 5 years, they can buy medicare, around $600 per month -nabao- ♀ (124 bytes) () 03/11/2010 postreply 20:57:08

• http://www.nycmccap.org/guide/chap12b.html -nabao- ♀ (84 bytes) () 03/11/2010 postreply 21:13:22