Original Medicare is not free for most people, unless you are on Medicaid or a Medicaid waiver or a State Medicare Savings Plan. Most people not on these plans will see their costs for Medicare rise in 2020. The cost for Part A (Hospital coverage) is $0 for most people due to working and paying for this coverage through wage deductions; however, Part B (Doctor coverage) carries a premium starting at $144.60 in 2020 and up based on income. The deductibles (meaning you pay first) is also going up for Part A ($1408 for days 1-60, $352/day for hospital stays days 61-90, and $704/day for 60 lifetime reserve days and then no coverage beyond the lifetime reserve days). The deductible for Part B is going up to $198.
You can see all of these in detail on the CMS Fact Sheet found here: https://www.cms.gov/newsroom/fact-sheets/2020-medicare-parts-b-premiums-and-deductibles