It is very difficult to argue that efforts in the United States to plan healthcare have been successful. The US healthcare system is not in particularly good shape. To the extent that the system of planning has been responsible for this, it has not done well.
First, though, we must acknowledge that most of the US healthcare system is not planned. This is not a system that the government largely controls. Instead, it is a system that has come about in large part through private enterprise, though it has been strongly affected by government regulations and programs.
That said, government planning has not worked out very well. For one thing, there are still many people who are not insured. This is partly because of a lack of governmental programs to either insure poorer people or to help them to buy insurance. This is a serious defect in the system. Perhaps the biggest problem, though, is the fee for service model on which Medicare, in particular, runs. Medicare has done well by covering all seniors, but it has helped to create perverse incentives in our system. It pays doctors based on how many services they provide, not on how well their patients do. This gives them incentives to order more and more tests and procedures while patients have few incentives to decline those orders. This has done a great deal to cause problems in our system.
Thus, while not all of the US healthcare system is planned, those parts that are planned have not been very successful in providing care to everyone or in keeping costs down.