Except for several periods of study leave, mainly in Freiburg and Tubingen, Foster continued to work at Berkeley until he retired in 1971. Alfred and Else Foster brought up their two sons and two daughters in Berkeley.
Maliban sa ilang panahon ng pag-aaral umalis, pangunahin sa Freiburg at Tubingen, Foster patuloy na magtrabaho sa Berkeley hanggang siya ay nagretiro sa 1971. Alfred at Iba Pa Foster nagdala up ang kanilang dalawang anak at dalawang anak sa Berkeley.