This geezer’s retirement home could wind up being the big house.

The feds say an elderly stickup man should get at least 12 years in the slammer for a botched Midtown bank robbery last year.

Career crook John Stolarz, 70, deserves no mercy “if there is to be any chance of deterring [him] from committing future crimes,” prosecutor Rachel Maimin wrote in a Manhattan federal court filing.