Legal Question in Family Law in Colorado

If it is titled as a Premarital Agreement, then no. You can sign the same sort of agreement during the marriage, which is called a "Martial Agreement." For a marital agreement to be valid, you really want the other party to have an attorney review it (often the party who wants the agreement will pay for the other party's attorney - have them choose their own attorney) and the agreement needs to provide disclosures of each party's assets or financial obligations. Keep in mind that a martial agreement can always be held by a court to be invalid as to maintenance (a/k/a, alimony) if it is unconscionable at the time of enforcement (e.g., after a 20 year marriage, one party would be left penniless if the agreement was enforced). I hope this helps.