There are numerous models:
Single Payer: eg the NHS in UK. Single payer pays all costs and wages, care is free at the point of contact (GP/Specialist/Hospital), prescription prices capped for pharma approved by NICE.
Scheduled Reimbursement: eg Australia. All services have a set scheduled fee, if "bulk billed" then free at point of contact. If not, then gap is payable for GP/Specialist services, or in private hospitals or as "private patient" in public hospitals. Gap can be covered for hospital care by private insurance, which is subsidized. Prescription prices capped for pharma approved by PBS. Private insurance regulated in terms of what is covered and limits due to pre-existing conditions etc.
Regulated Insurance: eg Germany/other EU. Health insurance is "compulsory" for all residents, with costs split between employee/employer, or picked up by government for unemployed. Insurance companies strictly regulated in terms of margins, "medical loss ratios", coverage etc.
All of these models provide better overall care and better overall outcomes for the country than the current US system. In particular, these aspects of the US system cause a large majority of the issues:
1. Lack of Transparency: Medical providers (hospitals/GPs/Specialists) are not required to publish a fixed price for services delivered, with opaque contractual relationships with payers.
2. Pharma: No regulation on prices, windfall taxes on excessive profit, universal availability, or even the negotiation on prices when government purchases.
3. Insurance Company Profit: The overall limit of 20% margins is excessive. There is no reason that insurance companies should be guaranteed this gross margin, when the actual cost of the service they provide is 10% of that, based on the costs incurred by government equivalents such as Tricare and Medicare.
So the solution is not "Let US pharmacies buy drugs from Canada where its cheaper". The solution is: "Let government programs negotiate with pharma companies to use their purchases to reduce prices" and "Require all medical service providers to publish their actual prices transparently and comparably without being able to negotiate secret reductions based on bulk purchases by insurance companies".