Mont. Code Ann. § 52-2-604

When the legal custody of a youth is vested in a public agency under the provisions of this part, the public agency may transfer physical custody of the youth to an appropriate private agency and may purchase care and treatment from the private agency if the private agency submits periodic reports to the public agency covering the care and treatment the youth is receiving and the youth's responses to that care and treatment. These reports shall be made as frequently as the public agency or the court deems necessary, but not less often than once each 6 months for each youth. The private agency shall also afford an opportunity for a representative of the public agency to examine or consult with the youth as frequently as the public agency deems necessary.