Yes, SteamTrain, your response sounds right. The instructions for box 12 explicitly state that 414(h) contributions are not be included in box 12 but are to be included in box 14 as information to the employee:
"Do not report in box 12 section 414(h)(2) contributions (relating to certain state or local government plans)."
Code D is only for 401(k) contributions. 414(h) applies only to 403(b) contributions. If the 403(b) contributions were not picked-up by the state under 414(h) they would be reported with code E, not code D.
Is it possible that the employer mistakenly deposited the 403(b) contributions into the 401(k) instead?
