Is anyone familiar with Rev Rul 84-45. It has to do with assumptions in connection w/ computing estimated earnings history when determining SS PIAs for plans that incorporated PIAs. I'm wondering if anyone knows any of the specifics w/r to what are acceptable assumptions to use based on this ruling.

First, you may want to dig out a copy so you can review the actual language. Going on memory (I haven't seen an offset plan since 1989) I believe the key statements concerned the earnings history for the individual. I recall 6% being an acceptable prior salary history backwards scale (for prior years before employment with the plan sponsor) or using National Average Earnings as an acceptable substitute. I also recall that you had to provide the participant with the ability to get their actual earnings history from SSA to use in the calculation. If I remember correctly, for terminated vested calculations we always got the actual earnings history from SSA before releasing any calculations for distributions.