No. You do not need, nor should you expect a Form 1099-R for the portion of your 401(k) balance distributed to your former spouse. A “qualified domestic relations order” (QDRO) is a domestic relations
order that creates or recognizes the existence of an “alternate payee’s”
right to receive all or a portion of the benefits payable with respect
to a participant under a retirement plan, and includes certain
information that meets other requirements.
You should refer to your Marital Property Settlement Agreement and your Divorce Order, as those documents are the final authority on these matters, but distributions such as this are almost never alimony; they are usually part of the division of marital property, and are without tax effect.
