Mont. Code Ann. § 72-6-214
Accounts and transfers nontestamentary
72-6-214 . Accounts and transfers nontestamentary. Except as provided in Title 72, chapter 2, part 2, or as a consequence of and to the extent directed by 72-6-228 , a transfer resulting from the application of 72-6-212 is effective by reason of the terms of the account involved and this part and is not testamentary or subject to Title 72, chapters 1 through 5.