Not legally divorced..still married but haven't lived together for 20years can I collect on his ss?

Hi. Possibly, but only if you're at least age 62, and if your husband is drawing Social Security retirement or disability benefits. Furthermore, if you were born after January 1 1954 then you could only qualify for spousal benefits during your husband's lifetime if his primary insurance amount (PIA) is more than twice as much as your PIA. A person's PIA is equal to their Social Security retirement benefit rate if they start drawing their benefits at full retirement age (FRA).

Best, Jerry