I read an article on a financial website a few months ago about this, and filed it away as something that I might be able to use in the future. Yesterday I was talking on the phone with someone from this site who knows a lot about financial planning and it came up in our conversation (I was looking to confirm it). He was not aware of it. That surprised me. So I contacted several people I know who are knowledgeable. So far 3 of the 4 who answered said they were not aware of it. One confirmed it but has no IRS references yet. I have found a few things that say some others consider it fact, but still no hard references in IRS pubs. Guess I might have to contact them directly and ask for references because this could matter for me next year. I suggest that unless someone posts hard references here that you personally confirm this, which I know I will do.

Probably everyone who uses a 401k knows the limits on elective deferrals as it applies to their age group. Most probably know the overall limit of $52,000 total contributions. But did you know that that second limit is a PER PLAN limit, not per person like the elective deferral limit? So if you work a day job, and contribute to a 401k plan, you can potentially have up to $104,000 including profit sharing contributions if you also have a solo 401k plan. I did see references to requirements concerning different employers. For example you can't have plans under two companies you own.