The upper middle class is mostly the upper level &/or specialized professional class. The upper middle class consist of doctors, lawyers/attorneys, professors, middle to upper level managers, & lower level executives. This is a very socioeconomically comfortable class. They are, on average, highly educated, with the minimum educational level being a Master's Degree. The upper middle class is the most educated of the middle class.
The upper middle class is now classified as being from about $75K-200K per year. This class can afford to live in better neighborhoods, send their children to private schools & colleges, enroll their children into cultural & intellectual activities, & can go on vacations. This is the class who is at least 4-6 paychecks away from being homeless.
The lower upper class is the higher echelon of professionals. They are the specialists in doctors w/some being heads of their specific specialities. Many are executives. Some may be even successful entrepreneurs. They are on the lower scale of wealthy but haven't yet arrived. They either possess an inordinate degree of education, have a specialized education which puts them in demand, or have a talent for branding themselves.
They are the specialists, owners, & shot callers of the work world. They are at least 6 paychecks away from homelessness. They can afford to live in the more upscale neighborhoods w/ the related amenities. They are what one would call affluent. They are the ones who have two houses & perhaps a maid/nanny which the upper middle class definitely DON'T have. They earn from $200K-$550K per year.