The wording that creates it
Under MCA § 70-20-310, joint tenancy with right of survivorship exists whenever the conveyance itself grants it. Montana State University Extension guidance, drawing on decades of educating property owners, describes the typical wording as "as joint tenants with right of survivorship and not as tenants in common." One detail worth flagging directly: the word "or" between owners' names is typically not used on a Montana real estate title or deed — a bare listing of names with no joint tenancy language, such as simply "John Jones and Mary Jones," is instead read as a tenancy in common by default.
Joint tenancy beats a will
Property held in joint tenancy with right of survivorship passes automatically to the surviving joint tenant, even when the deceased owner's will names someone else entirely to receive it. Montana extension education materials describe this directly with worked examples: if a father wrote a will leaving his interest in jointly titled property to his son, but the property was actually held in joint tenancy with his surviving co-owner, the co-owner still receives the whole property by operation of the joint tenancy — the son gets nothing from that specific asset, regardless of what the will said.
The real case: two states, one crucial question
A real Montana family learned this lesson the hard way. A married couple held property in joint tenancy with right of survivorship. When the husband died in Tennessee and the wife died in Montana, the family had to spend roughly $5,000 in legal fees just to establish, formally, that the mother was the first of the two to die — a legal process spanning two different states that took months to resolve. The adult children were genuinely shocked by both the cost and the time involved, all because this single factual question determined how the jointly held property was actually distributed.
Why that single fact mattered so much: the 120-hour rule
Montana law specifically addresses what happens when joint tenants die close together in time. If it cannot be established that one joint tenant survived the other by at least 120 hours (five days), the outcome is genuinely different from ordinary survivorship: rather than the whole property passing to whichever tenant is presumed to have survived, half of the property is distributed to the devisees or heirs of one joint tenant, and half to the devisees or heirs of the other. In effect, the property gets split between each side's separate heirs, as though neither joint tenant actually survived the other for inheritance purposes. This is exactly the kind of factual question the family in the case above had to resolve at real cost.
Divorce ends it automatically
A real Montana Supreme Court decision confirms something genuinely different from what several other states do: a dissolution of marriage automatically terminates a joint tenancy with right of survivorship between the former spouses, converting the property into a tenancy in common instead. The court applied this rule directly, holding that the district court correctly converted jointly titled property into a tenancy-in-common interest once the marriage ended, without needing any further action by either former spouse to accomplish that conversion.
A separate, more modern tool for real estate
None of this changes the fact that Montana also offers separate, deed-based routes for keeping real estate out of probate entirely. See our guide to Montana's beneficiary deed and transfer-on-death deed for how those tools work alongside these joint ownership rules.