In [1] and [3] weighting procedures were developed for obtaining unbiased longitudinal household (LHH) and family estimates for SIPP. As noted in these papers and also in [2], except for certain LHH definitions it does not appear possible with the original SIPP operating procedures to develop an unbiased weighting procedure without serious drawbacks. These drawbacks include the assignment of positive weights to some LHH’s that were not in sample for their entire period of existence during the life of the panel, or the lack of sufficient information to assign weights to some LHH’s because some of the necessary information pertained to time periods when the LHH’s were not in sample. These previous papers were handicapped by the fact that the choice among weighting methods and the changes in operational procedures necessary to overcome the problems just described are dependent on the LHH definition adopted for SIPP, and no LHH definition had been agreed upon at the time these papers were-written. Now, however, a definition does exist which has been tentatively adopted (Attachment A). Although this particular definition does require changes in SIPP operating procedures in order to obtain unbiased estimates without the drawbacks previously mentioned, only two relatively simple changes are required. One of these changes has already been implemented for this purpose and the other is planned.