@Carl why do you say the 709 is not really a return? It is titled "United States Gift (and Generation-Skipping Transfer) Tax Return" and I.R.C. 6103(b)(1) says 'the term “return” means any tax or information return, declaration of estimated tax, or claim for refund required by, or provided for or permitted under, the provisions of this title which is filed with the Secretary by, on behalf of, or with respect to any person, and any amendment or supplement thereto, including supporting schedules, attachments, or lists which are supplemental to, or part of, the return so filed."'
But I'm not sure why the name/type of the form matters. The form clearly states, as @tagteam says that it is only for that particular year's gifts. (Probably because the amounts change year by year, both the annual exclusion and the unified credit (or whatever it is called these days).
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
