In my opinion, the Universal Health Coverage of Thailand and the health care system in the USA are different but it makes sense.
For US citizens, they have to pay for the healthcare service as much as they can afford it, which means the quality of health service will depend on how much they pay for.
But for Thai citizens with UHC programs which the government announced which services are included in the program and which services are not included. For the quality of the medical services, I heard some of the services or some of the medicines cannot use in this program while other programs like Social Security Scheme or Government Or State Enterprise Officer are covered more. But it makes sense because UHC has to cover all of the Thai citizens and a lot of money has to spend per year.