In most cases, the  Stieberger DEVELOPMENT PERIOD will begin the 48th month immediately preceding the date of SSA's
                  receipt of the request for review and end at the point of readjudication. In some
                  cases, however, the DEVELOPMENT PERIOD may begin earlier or later, or may even be
                  two (or more) non-consecutive periods in all. (See B., which contains FO rules for
                  computing the DEVELOPMENT PERIOD.)
               
               There are some instances in which the DDS may have to develop for the entire retroactive
                  period. (See C. below.)