What reform does Medicare need?
Nothing, besides the fact it is hugely expensive, and along with other major entitlements, is incurring huge debt, and ever-growing interest payments
https://www.forbes.com/sites/howardgleckman/2018/06/06/no-medicare-wont-go-broke-in-2026-yes-it-will-cost-a-lot-more-money/#596203cd7eb1
https://www.heritage.org/medicare/commentary/medicare-will-be-insolvent-2026-can-america-fix-it-time
Allow people to opt out of Medicare and not lose social security.
Give those that opt of of Medicare a voucher (in lieu of Medicare coverage) towards the purchase a private policy. To save money for the program, the voucher could be less than the cost of Medicare coverage.
Allow Medicare patients to see doctors (that accept Medicare) and engage in private contracting and negotiate prices.