Medicare.gov has a page telling you which Medicare Supplement standardized plans offer which benefits. That page is located at https://www.medicare.gov/supplements-other-insurance/how-to-compare-medigap-policies.

A note on that page states: “As of January 1, 2020, Medigap plans sold to new people with Medicare aren’t allowed to cover the Part B deductible. Because of this, Plans C and F are not available to people new to Medicare starting on January 1, 2020. If you already have either of these 2 plans (or the high deductible version of Plan F) or are covered by one of these plans before January 1, 2020, you’ll be able to keep your plan. If you were eligible for Medicare before January 1, 2020, but not yet enrolled, you may be able to buy one of these plan.” In 2020, the Part B deductible is $198.

Information regarding 2020 deductibles and premiums is at https://www.cms.gov/newsroom/fact-sheets/2020-medicare-parts-b-premiums-and-deductibles#:~:text=The%20annual%20deductible%20for%20all,spending%20on%20physician%2Dadministered%20drugs.

A different page provided by Medicare allows you to locate available Medicare Supplement Plans: https://www.medicare.gov/medigap-supplemental-insurance-plans/#/m