A divorce (in Montana, a dissolution of marriage) after a long marriage runs under the same statutes as any other. What changes is the weight of one factor. The length of the marriage is something the court must consider when it divides property and when it decides maintenance, and after many years together there is usually more to divide and less working time to rebuild. This page is part of our Montana Divorce Guide and also serves as a map to the other special situations the guide covers.
Montana Does Not Define a Long Marriage
You will not find a line in the Montana Code at 10, 20, or 30 years. Neither the property statute nor the maintenance statute sets a threshold, and neither gives a formula tied to years married. Both simply list duration of the marriageamong the things a judge must weigh. That means two marriages of the same length can come out differently because the spouses' ages, health, earnings, and property are different.
The federal rules that sit alongside a divorce do use bright lines, and those are covered below.
How Duration Figures in Property Division
Under MCA § 40-4-202(1), the court must, without regard to marital misconduct, equitably apportion the property and assets belonging to either or both spouses, "however and whenever acquired," no matter whose name is on the title. In doing so it considers the duration of the marriage along with each spouse's age, health, occupation, income, vocational skills, employability, liabilities, and needs, and the opportunity of each to acquire capital assets and income in the future.
Two parts of that list matter more as the years add up. First, the court must consider "the contribution of a spouse as a homemaker or to the family unit." Second, for property one spouse brought into the marriage or received by gift or inheritance, the court considers the other spouse's contributions to the marriage, including whether they helped maintain that property. Our guides to how property is divided and separate and marital property go through this in detail.
How Duration Figures in Maintenance
Maintenance is not awarded because a marriage was long. The court may order it only if the spouse asking lacks sufficient property to provide for reasonable needs and is unable to be self-supporting through appropriate employment (MCA § 40-4-203(1)). If that test is met, the amount and period are what the court considers just, after weighing six listed factors. They include the standard of living established during the marriage, the duration of the marriage, the age and physical and emotional condition of the spouse seeking maintenance, and the other spouse's ability to meet their own needs while paying (§ 40-4-203(2)).
There is no formula and no statutory cap or minimum on how long maintenance lasts. Unless the decree or a written agreement says otherwise, the obligation to pay future maintenance ends when either person dies or the person receiving it remarries (MCA § 40-4-208(4)). See spousal maintenance in Montana and how long maintenance lasts.
Retirement Accounts and Pensions
Because the court reaches property "however and whenever acquired," retirement savings are part of the estate to be apportioned. Dividing them takes the right paperwork. For an employer plan covered by federal pension law, the plan pays a former spouse only under a qualified domestic relations order (29 U.S.C. § 1056(d)(3)). An individual retirement account can be transferred to a former spouse under a divorce instrument without the transfer being taxed to the person giving it up (26 U.S.C. § 408(d)(6)). Montana seals a qualified domestic relations order from public view (MCA § 40-4-202(6)).
Read dividing retirement accounts and QDROs before you agree to trade a retirement account against another asset. A tax professional should look at the after-tax value of what each of you would keep.
Social Security's 10-Year Rule
Social Security is the one place where a number of years decides something outright. Federal law defines a divorced spouse, for benefit purposes, as someone who was married to the worker for 10 years immediately before the divorce became effective (42 U.S.C. § 416(d)). A divorced spouse who meets that test, is at least 62, is not married, and has a smaller benefit of their own may be entitled to a benefit on the former spouse's record (42 U.S.C. § 402(b)(1) and (c)(1)).
A Montana court does not divide Social Security in the decree. Federal law makes the right to future payments nontransferable (42 U.S.C. § 407(a)). The Social Security Administration can tell you what you would receive on each record.
Health Coverage After the Decree
Divorce is a qualifying event under COBRA (29 U.S.C. § 1163(3)). A former spouse who was covered under an employer group health plan can elect to continue that coverage for up to 36 months (29 U.S.C. § 1162(2)(A)(iv)). The employee or the former spouse must notify the plan administrator within 60 days of the divorce (29 U.S.C. § 1166(a)(3)), and COBRA does not apply to plans of employers that normally had fewer than 20 employees (29 U.S.C. § 1161(b)). Losing coverage because of a divorce also opens a special enrollment period on the Marketplace, according to healthcare.gov. Medicare is individual: each person qualifies on their own age or disability.
A Guide to the Other Special Situations
| Situation | What the article covers |
|---|---|
| Divorce after 50 | Retirement accounts, Medicare, Social Security, and beneficiary updates when there is less working time left. |
| A short marriage | How duration and premarital property are weighed when the marriage was brief. |
| Military service | Filing while stationed here, federal stay and default protections, and military retired pay. |
| A spouse in another state | What a Montana court can and cannot decide about a spouse it has no personal jurisdiction over. |
| Pregnancy | What the petition must say, why summary dissolution is unavailable, and the parentage presumption. |
| Domestic violence | Safety, orders of protection, the mediation exception, and parenting factors. |
| A child with a disability | Parenting plans, support that can continue into adulthood, and public benefits. |
| Same-sex spouses | The same statutes apply. The marriage date and parentage need extra attention. |
| A stay-at-home parent | Homemaker contributions, maintenance, temporary orders, and fee awards. |
| Property in another state | How a Montana decree reaches real estate located somewhere else. |
| Immigration status | Conditional residence, the joint filing waiver, and the affidavit of support. |
A&M Law is a Missoula family law firm. Many long-married couples want to finish the marriage with respect, and our Cooperative Family Law process is built for spouses who can meet together and work through these questions with the firm serving as a neutral. We also represent individual clients in traditional cases through our divorce practice.
This page explains Montana and federal law in general as of the 2025 Montana Code Annotated. It is not legal, tax, or benefits advice about your specific case.