When the sale is held
There is no sale date to attend. The statewide calendar is fixed by statute rather than published per county. The treasurer publishes or posts the notice of pending attachment on or before the last Monday in June, mails the assessed owner a notice at least 2 weeks before attaching, and attaches the tax lien no later than the first working day in August. An investor who wants an assignment must mail the assessed owner the statutory notice of pending assignment by certified mail at least 2 weeks before paying, and that notice may not be sent earlier than August 15 or more than 60 days before the purchase, so the earliest practical assignment date in any county is about August 29. Assignments of unclaimed liens remain available from the treasurer year round after that.
When taxes go delinquent
Montana property taxes are billed in halves. The first half is payable by 5 p.m. on November 30, or within 30 days after the tax notice is postmarked if that is later, and the second half by 5 p.m. on May 31. An unpaid half is delinquent from that moment, draws interest at 5/6 of 1 percent a month until paid, and has a one time 2 percent penalty added to it. Taxpayers on the alternative payment schedule for primary residences pay one seventh each month from November 30 through May 31 and fall under the same interest and penalty if a payment is missed. A taxpayer may pay the current year without clearing an older delinquency, and paying the current year is not a redemption of any earlier tax lien. Parcels still delinquent at the end of that cycle get a county tax lien attached no later than the first working day in August.
What happens after the sale
Montana runs no scheduled county tax deed auction and no calendar of deed sales. Two different endings apply once the redemption period runs out, and which one applies is a property of the parcel. For ordinary property the treasurer simply grants the assignee a tax deed under 15-18-211 for a 25 dollar deed fee plus the county's actual notice costs, with no auction and no bidders. For property that contains a dwelling currently occupied by the legal titleholder of record, and that is classified residential under 15-6-134, agricultural under 15-6-133(1)(a) or (1)(c), or forest under 15-6-143, the assignee may not take the deed directly. Under 15-18-219 the assignee files an application with the treasurer and pays a 25 dollar application fee, the redemption amount on any unassigned liens or liens held by other assignees, any delinquent taxes, penalties and interest, and the current taxes. The treasurer then holds a public auction in the county within 60 days of receiving that application, under 15-18-220. That auction exists so the owner's equity is paid out rather than forfeited, which is why the opening bid carries half the assessed value. If no assignment was ever taken, no deed issues to the county unless the county commissioners direct the treasurer by resolution.
Leftover parcels between sales
Every Montana tax lien is over the counter, because that is the only way one is ever acquired. The county holds the lien from the moment it attaches, and 15-17-323(1)(a) requires the treasurer to assign it to any person who first mails the assessed owner a notice of pending assignment by certified mail and then pays the delinquent taxes, penalties, interest and costs. The notice must be mailed at least 2 weeks before the payment, not earlier than August 15 and not more than 60 days before the purchase, and the buyer must hand the treasurer proof of the mailing. Counties add their own assignment fee, which ran from 50 to 75 dollars per parcel at the offices checked for this record. The treasurer issues an assignment certificate in the statutory form, mails a copy to the assessed owner, and files a copy with the clerk and recorder. In the first days after attachment most counties run an allocation step because several investors want the same parcels, and after that step the remaining liens sit with the treasurer and can be assigned on demand for the rest of the year. An assignee may pass the lien on to a new assignee for any consideration, which is binding only once a signed statement naming the old and new assignees and describing the property is filed with the treasurer.
These dates are the statewide statutory schedule. The exact auction date, registration deadline, and platform are set county by county, so confirm them on the Montana county pages before you plan a bid. For the mechanics of the sale itself, see how to buy in Montana.
Verified Sep 10, 2026 against Montana statutes.
Tax Sale Atlas publishes educational information about public tax sale processes. This is not legal, financial, or investment advice. Rules, dates, and fees change; confirm with the county office before you bid.