Yes, parties can agree in their separation agreement to make maintenance nonmodifiable if the agreement clearly says so. Colorado statutes allow separation agreements to control future modifications when the parties expressly provide for that result. Without such language, maintenance is generally modifiable upon a substantial and continuing change of circumstances. Courts look for explicit nonmodifiable wording to limit later changes. You should get careful legal drafting to avoid ambiguity. Filing a clear agreement helps the court enforce the parties’ intent.