How does one go about division of spouse TSP (401K)?

I don't think so. I believe since he can't touch it, it would not count as income. I suppose the real question is does it show up on his W-2? If not, then I doubt the court will consider it.

In South Carolina, there are a lot of factors that must be considered when making these calculations / determinations. However, I do not believe that the the bi-weekly matching amount can be considered as a part of his income to figure maintenance and child support. If the retirement account is a 401 K, then (dependent upon your Court Order) it is most likely the case that you cannot begin to receive distributions until he does. These matters can get very complicated very quickly. You should consult with a local attorney as soon as possible regarding this matter. I do hereby clearly advise against any reliance on the information as advice or application of it to a specific situation without a more thorough consultation with counsel.

A Qualified Domestic Relations Order (QDRO)will divide the TSP. That should be done at the time of divorce. Support amounts will be determined based upon his gross wages( taxable and nontaxable). The matching amount is part of his gross wages.