Usage patterns
老後に備えるto prepare (financially/practically) for one's old age
I'm saving money every month to prepare for my old age.
老後を過ごすto spend/live out one's retirement years (in a certain way)
I want to spend my retirement years peacefully in the countryside.
老後の生活life in one's old age; retirement lifestyle
I'm worried about my life in old age.
老後の心配worry/concern about one's later years
I want to live without worrying about my old age.