It depends on several factors, including state marriage laws. If the structured settlement was awarded during the marriage and you live in a community property state, a structured settlement from a civil lawsuit may be divided between the two spouses because joint property is usually divided equally. The exception is if you and your spouse have a prenup with a specified arrangement.
However, if you received the settlement before the marriage, you may be entitled to keep the entire amount, particularly if you live in a state with equitable distribution. Even if assets are jointly owned in an equitable distribution state, they may not be divided equally. The court considered many different factors.