18-1-301. Contractor withdrawals -- deposit of obligations. (1) The contractor under any contract made or awarded by the state of Montana or any department, agency, or political subdivision of the state of Montana, by any county, municipality, or political subdivision of a county or municipality, or by a school district, including any contract for the construction, improvement, maintenance, or repair of any road or highway or the appurtenances to a road or highway, may, from time to time, withdraw the whole or any portion of the sums otherwise due to the contractor under the contract that are retained by the state of Montana or any department, agency, or political subdivision of the state of Montana, by any county, municipality, or political subdivision of a county or municipality, or by a school district pursuant to the terms of the contract, provided the contractor shall deposit with the contracting agency:
(a) United States treasury bonds, United States treasury notes, United States treasury certificates of indebtedness, or United States treasury bills;
(b) bonds or notes of the state of Montana;
(c) bonds of any political subdivision of the state of Montana of a market value not exceeding par at the time of deposit; or
(d) certificates of deposit drawn and issued by a national banking association located in the state of Montana or by any banking corporation incorporated under the laws of the state of Montana.
(2) Deposited obligations must be at least equal in value to the amount so withdrawn from payments retained under the contract.
(3) Except as provided in subsection (4), all interest accrued in the accounts of deposits required under this section must be paid to the contractor.
(4) The contractor shall extend to the contractor's subcontractors the opportunity to participate in making the deposits required in subsection (1). Interest accrued in deposit accounts in which subcontractors participate must be distributed on a pro rata basis by the contractor to the participating subcontractors. A subcontractor participating in making the deposits required in subsection (1) may not have additional retainage withheld by the contractor.