Items reported with codes BB and EE in box 12 of your W-2 are Roth contributions to the 403(b) and 457(b), respectively, and do not reduce the amount that your employer reports in box 1 of your W-2.
Item reported with codes E and G in box 12 of your W-2 are elective deferrals to the 401(k) and 457(b), respectively, and are pre-tax, not post tax, because your employer excludes these amounts from the amount in box 1 of your W-2.
TurboTax presently has a bug that flags maximized 457(b) contributions combined with maximized contributions to another type of qualified retirement plan such as a 403(b) as excess contributions because they exceed $18,500 when, in fact, the permissible total is $37,000. To e-file you'll need to wait for the TurboTax developers to fix this, otherwise you'll need to file by mail. There might be a fix in the April 5 update.
