Caller id: MEDICAL SRV GRP.  Answered, someone from a call center with foreign (India perhaps) accent.  Claimed calling from US, represented a medical service group, that they were evaluating my Medicare situation, they knew of my existing medical conditions, opening spiel gave gave me the impression caller was US Medicare, when challenged admitted not from Medical, then stated they wanted to review my situation so they could recommend an Advantage or Supplemental policy.  I repeatedly told them I was not interested but kept stringing me alone until I hung up.

Probably not a scammer but decidedly a hardcore telemarketer with the usual misleading and misdirection techniques of questionable ethics.