If a participant is due only $15 as her vested interest, is this distribution subject to the same consent rules as a $3,000 distribution? I realize it is exempt from withholding, but it seems bizarre to have all that paperwork for such a tiny amount. Is there any exception here? What is the normal TPA practice in this case? Thanks for all input!

I know of no consent requirement imposed by law for a distribution less than $200 where that is the only distribution to the participant during the plan year.

Assuming you are referring to the mandatory 20% withholding on lump sum amounts distributed other than a direct rollover, there is no withholding (at least for federal purposes) below $200. That is, the $15 balance is subject to the same rules, but the amount of withholding is $0. However, such participant should still receive the "special tax notice".