1 I celebrate myself, and sing myself, And what I assume you shall assume, For every atom belonging to me as good belongs to you. I loafe and invite my soul. The US Centers for Medicare and Medicaid Services CMS is the largest purchaser of healthcare in the nation serving almost 123 million people, more than one in. International Journal of Engineering Research and Applications IJERA is an open access online peer reviewed international journal that publishes research. Comprehensive and meticulously documented facts about healthcare. Learn about costs, private insurance, Medicare, Medicaid, politics, and more.