But since you want to eliminate any choice, it will actually be Medicaid for all and there won't be any doctors and nurses left to actually provide it.
But if you want to reduce costs closet to other countries, then just pay doctors and nurses less and reduce services.
"Why does the United States spend so much more? The biggest reason is that U.S. healthcare delivers a more expensive mix of services. For example, a much larger proportion of physician visits in the U.S. are to specialists who get higher fees and usually order more high-tech diagnostic and therapeutic procedures than primary care physicians."
"Compared with the average OECD country, the U.S. delivers (population adjusted) almost three times as many mammograms, two-and-a-half times the number of MRI scans, and 31 percent more C-sections. Also, the U.S. has more stand-by equipment, for example, 1.66 MRI machines per 6,000 annual scans vs. 1.06 machines. The extra machines provide easier access for Americans, but add to cost. Similarly, occupancy rates in U.S. acute care hospitals are much lower than in OECD countries, reducing the likelihood of delays in admissions, but building that extra capacity adds to cost. Aggressive treatment of very sick elderly also makes the mix expensive. In the U.S. many elderly patients are treated in intensive care units (ICUs), but in other countries they would receive only palliative care. More amenities such as privacy and space in hospitals and more attractive clinics also add to U.S. costs."