Q: I am retiring at the end of December and have already reached age 65. I have signed up for Social Security benefits starting in January. I also signed up for Medicare Part A coverage but not Part B coverage, as suggested at a retirement seminar. I am carrying over my Federal Employees Health Benefits coverage. I checked with my plan and they said I would not need Medicare Part B. If I decide to switch plans in the future and my new insurer suggests that I need Part B coverage, will I be penalized with the 10 percent per…