Those are Suopplement Plans, Medigap style. Diff things

Everybody has his own need based on his own health status, heritance risk factors, life styles.  Balance the benefits versus the Costs.  AARP and United definitely want you to buy the supplement plans by playing up the FEAR FACTORS.  If you feel it is worth it to buy for "Peace of Mind" and dont care about the costs (as most here should have enough wealth to not care for savings on premiums) then go for those. 

That is WHY it is a Good Things there are many options available for you to choose from, versus some feel it should make it simple without choices. (only good for those who are lazy to learn or stupid enough not to understand the differences).