If "fed"= federal reserve board or regional banks, then YES, anyone even non-U.S, citizens and non-greencard holders can apply (I know many former classmates that are not American citizens at the fed board and fed regional banks).
If "fed"= other federal government jobs (FTC, DOJ, BLS, CBO, etc), then generally no, you have to a be a U.S. citizen (even green card holders will not qualify for most of these jobs to my knowledge)