Medicare is reasonably cheap (assuming you paid Medicare taxes for at least 7.5 years; if you did not, it's at least $471/month). To be clear, "relatively cheap" is "at least $148.50/month; more if you have more income during retirement".
But past the premiums, there are deductibles, coinsurance (e.g. for hospital stays longer than 60 days), you still have to pay for medicines (how much varies), etc. See https://www.medicare.gov/your-medicare-costs/medicare-costs-... and the links from it for details.
But past the premiums, there are deductibles, coinsurance (e.g. for hospital stays longer than 60 days), you still have to pay for medicines (how much varies), etc. See https://www.medicare.gov/your-medicare-costs/medicare-costs-... and the links from it for details.