From an AP story by Jessica Gresko headlined “Supreme Court Justice Breyer has options as a retiree”:

Until last week when he swore in Justice Ketanji Brown Jackson, his successor on the Supreme Court, Justice Stephen Breyer had a rigorous, intellectually challenging job with the highest of stakes. Now the 83-year-old retiree has no briefs to read and no opinions to write.

As a retired justice, Breyer can maintain an office at the Supreme Court if he wants to and also gets a clerk to help him. But like other retired justices he also gets to chart his own path based on his personality and interests. One example: Justice Sandra Day O’Connor, the court’s first female justice, in retirement founded a group that teaches students civics through computer games.