The issue of federal health care policy raises issues of federalism because it creates a situation in which the federal government might be trying to cause the states to do things that they do not want to do. Even if the states are not opposed to the federal government’s plans, they may not like being told that they must do those things. These are issues of federalism.
We can clearly see the issue of federalism at work in the arguments over the “Obamacare” plan. Many states sued the Obama administration because of this law. They did not think that Congress had the right to tell people in the various states that they had to buy health insurance. They felt that states could impose such a requirement (as they do with car insurance) but that the federal government could not. They also felt that the federal government was being excessively coercive when it tried to force them to expand Medicaid coverage. In both cases, the state governments felt that the federal government was infringing on their rights and powers.
Because federal health care policy can involve the federal government trying to tell states what to do, it gives rise to issues of federalism.