Hello again!
Well here we are in 2022, experiencing the joy of TT, 529 plans, and US Service academies.
I am not convinced that TT developers treat US Service Academies correctly for 529 purposes. Four military academies (West Point, AF, Navy, and Coast Guard) are not colleges for DoED purposes, but US Merchant Marine Academy ("USMMA") (DOT/MARAD) is a college on DoED's list of qualifying institutions. This means that qualified expenses at USMMA for books, computers, etc. should be treated as tax free withdrawals from a 529 plan, whereas they are not for the military academies. The academies are treated the same, however, for the 529 withdrawals in terms of avoiding the 10% penalty.
Based on the results I am getting for one kid at a DOD academy, and another at USMMA, I do not think that TT recognizes these differences. To avoid the 10% on a large withdrawal, I must tell the system that my kid was at a "military academy." When I put in qualified educations expenses for the USMMA kid, it tells me I cannot take those.
I do not know if there is a solution.
