Mutual Aid and Fire Protection Outside Cities
Mutual aid contracts are authorized under the Interlocal Cooperation Act. T.C.A. § 12-9-101, et seq. This act allows counties and cities to act jointly to provide services that each may provide separately, including fire service and law enforcement. (See also T.C.A. § 6-54-307, T.C.A. § 6-54-601–603.) An agreement made under the Interlocal Cooperation Act that creates an intergovernmental entity must be filed with the comptroller’s office within 90 days of execution. Joint venture entities created under this act must file an annual statement with the comptroller indicating the parties, annual revenues and expenses, and other information. T.C.A. § 12-9-112.

An incorporated municipality is authorized to enter into mutual aid or fire protection assistance contracts with other cities, counties, private incorporated and industrial fire departments, utility districts that provide fire protection, metropolitan airport authorities that provide firefighting service, or "an organization of residents and property owners of unincorporated communities." A city may enter into individual contracts with non-city residents or provide the service without a contract. In either event, both the city’s and county’s legislative bodies must approve the arrangement. T.C.A. § 6-54-601–603.

Counties with a countywide fire district may mandate that all interlocal agreements contain performance- based criteria designed to assure timely response and effective service. T.C.A. § 5-17-101.

The Mutual Aid and Emergency and Disaster Assistance Agreement Act (MAEDAAA) of 2004 (T.C.A. § 58-8-101, et seq.), authorizes municipalities to assist other governmental entities in certain occurrences and emergencies when the requesting and responding parties do not have a mutual aid agreement. This law acts as a state-wide mutual aid agreement for participating entities and provides for reimbursement as required in the federal policy noted below.

Federal policy, specifically Response and Recovery Policy Number 9523.6 of the Federal Emergency Management Agency, requires municipalities, in their mutual aid agreements, to require cost reimbursement by the entity receiving assistance in all instances if the municipality is to be reimbursed for aid in a presidentially declared disaster. Municipalities and entities acting under the MAEDAAA of 2004 in a state of emergency are required to reimburse responding parties, or to be reimbursed if they are a responding party, in accordance with this federal policy.

Hazardous Material and Natural Disaster Calls Outside the City
Cities incorporated under the general law city manager-commission charter (T.C.A. § 6-18-101, et seq.) may allow their fire departments to answer hazardous materials and natural disaster calls, regardless of where the emergency exists. T.C.A. § 6-21-703.