US Medicare Costs Now 7.5% of GDP

Five years ago, the youngest people born during the baby boom (a period of time with exceptional birth rates, from 1946, after the end of the Second World War, to 1965) reached age 65 and became eligible for Medicare. This year, Medicare provides coverage for 83 million people who are 65 and older or disabled.
The Medicare costs will continue to increase in the future, with another 10 million eligible by year 2055, with a total of 9.8% of GDP.
Argument: According to United States Department of Health and Human Services the costs for Medicare will be 7.5% of GDP by year 2035.
Questions: In 2077 there will only be two workers on every Medicare beneficiary, compared to four workers today, which will put a unprecedented pressure on the working generation. What kind of system is needed to take care of this problem?