So the drug company Glaxo Smith Klein or Pfizer (or both?) has been pushing

[Ms. Toad]

15. A supplement plan doesn't cover prescriptions.

Supplemental plans (medigap) plans covers part of the 20% of medical (not drug) costs that Medicare doesn't cover.

For prescription coverage you need a stand-alone part D plan, OR a Medicare advantage plan that includes drug coverage.

The law requires Medicare to cover RSV (and other CDC recommended vaccines) 100%. So RSV is covered 100% now.

The catch is that a few vaccines are considered medical (covered by original Medicare), and most are considered drugs (covered by part D).

You made a good choice to skip Medicare Advantage plans. But you need a separate part D plan. If you ever need expensive prescriptions you won't be able to get coverage without a part D plan.

If you have prescription coverage (part D), go back and ask the pharmacy to explain why it isn't following the law about coverage of CDC recommended vaccines (100% covered at an in-network pharmacy). If you don't, consider buying the cheapest plan available now to stop the penalty clock from ticking. A few bucks a month is worth the added vaccine coverage (shingles, RSV, tetanus, hepatitis, even if it covers nothing else) - not to mention making sure you can actually buy a plan when you need one without a massive penalty. My plan is free next year (it's been about $8); my spouses is a bit more - about $10/month - I don't know next years price.