Health and Human Services Secretary Sylvia Mathews Burwell said Monday she is confident that Obamacare subsidies will survive Supreme Court review. The case centers on the constitutionality of Affordable Care Act subsidies in states operating on the federal government's insurance exchange. Those subsidies have already gone into effect for nearly 5 million people, and could reach up to 7.4 million by 2016. Healthcare experts have warned that the case could gut the core of Obamacare, with at least $36 billion in subsidies at stake, but Burwell said she is not worried.