- Montana Legal Services Association

A landlord must keep the property in a fit and habitable condition. This includes keeping the electrical, plumbing, heating, and other facilities in good and safe working condition, and supplying running water. The landlord must also install an approved smoke detector.

A landlord may enter a dwelling unit without the tenant's consent only in case of an emergency; pursuant to court order; when the tenant has abandoned or surrendered the premises; to make repairs when a tenant has failed to do so after 14 days written notice; or, when reasonably necessary during a tenant's absence of more than seven days. A tenant may not unreasonably withhold consent to the landlord to enter the dwelling unit to inspect or make necessary repairs. The landlord generally must give the tenant at least 24-hours notice of the landlord's intent to enter and may enter only at reasonable times.

- Montana State Website - learn more about Montana

A security deposit is money given by a tenant, generally in advance, to secure payment to a landlord for damage to, or cleaning of the rented premises, or to secure payment of rent to the landlord. 
A Montana landlord who requires a security deposit must give a new tenant, before that tenant moves in, a statement of the condition of the premises.