Retired, but working. Does that describe you? It’s a living reality for people working full or part-time while they are enrolled in Medicare and perhaps even Social Security. The number of people aged 55 to 74 in the workplace jumped 30% in the first decade of this century, grew 20% more from 2010 to 2020, and is expected to rise by 7.7% more in the following decade, according to the Bureau of…