The #1 fact check should be the name. Medicare is a program that requires payment of the payroll tax to get Part A coverage and payment of the monthly premium to get Part B coverage. That gets you 80% coverage for covered services. If you want coverage for the other 20%, or for 100% on prescription drugs or vision or dental or any other service Medicare doesn't cover, you buy a separate private insurance plan. Otherwise you pay for all those things out of pocket.
The dems want you to think their proposal is medicare for all but it's really medicAID for all, and repubs need to start calling it that when we talk about it.