If a spouse has been claiming her retirement benefit for a few years, and the husband just now is claiming his benefit at age 70 and realizes he could have filed a restricted application, is he limited to claiming only six months of retroactive spousal benefits? Or could he protest and get spousal benefits for the full period that his wife has been collecting?
Hi. Normally the husband would be limited to 6 months of retroactivity, but if he was listed on his wife's application then that would establish a protective filing date for him (https://secure.ssa.gov/apps10/poms.nsf/lnx/0200204010). If that protective filing date was never closed out by Social Security (https://secure.ssa.gov/apps10/poms.nsf/lnx/0200204012), then the husband may be able to claim spousal benefits retroactive to when the wife started drawing.
The husband could ask for full retroactivity when he applies based on a presumed protective filing date from his wife's application. If Social Security disallows his request and if he believes that there was a protective filing that wasn't closed out, he could then file an appeal.