A presumption, not an absolute rule
Under ORS § 708A.470, sums remaining on deposit at the death of a party to a joint account are rebuttably presumed to belong to the surviving party or parties, against the estate of the decedent. That word "rebuttably" matters: it's a starting presumption, not an unbreakable rule, and it can be overcome with the right kind of evidence.
How the presumption can be overcome
The presumption can be rebutted by evidence establishing that the deceased party intended a different result, or that the deceased party lacked capacity when the joint account was established. Either showing shifts the outcome away from the default survivorship rule.
A 2003 change broadened what evidence counts
Before a 2003 amendment (SB 33), Oregon's statute specifically required that any contrary evidence be found in the bank's own account records at the time of death — a narrow, document-specific standard. The 2003 amendment removed that limitation, broadening the kinds of evidence that can be used to rebut the presumption beyond just what's literally written in the bank's own files. This gave courts more flexibility to consider the full picture of what a deceased account holder actually intended, rather than being limited strictly to the bank's paperwork.
Owning the right doesn't always mean immediate access
A published Oregon Court of Appeals decision addressed a related, practical wrinkle: a surviving party's ownership right in a joint account doesn't automatically give that party a right to immediate possession of the account funds if the account is the subject of an adverse claim. In other words, even where the survivorship presumption clearly applies, a competing claim against the account can still delay the survivor's actual access to the money while that claim gets resolved — ownership and immediate access are related but distinct questions.
The bank's own protections when paying out
Oregon law protects a financial institution that distributes funds to a surviving party in accordance with the account agreement, unless the institution had already received notice of an adverse claim and the adverse claimant followed the required procedure before the distribution happened. This gives banks a clear, practical path for handling routine account closures after a death, while still preserving a mechanism for someone with a genuine competing claim to intervene before funds go out the door.
P.O.D. designations, life insurance, and retirement accounts
A payable-on-death (P.O.D.) beneficiary designation works differently from joint ownership between co-owners. The named P.O.D. beneficiary has no rights to the account during the owner's life, and receives whatever remains only once the owner dies. Life insurance and retirement accounts like a 401(k) or IRA follow the same basic rule — the named beneficiary receives the asset directly, outside probate, as long as they're alive when the owner dies, and it only becomes part of the probate estate if no beneficiary was ever named or every named beneficiary predeceased the owner with no contingent beneficiary in place.