Each county is directed by general state law to invest all idle county funds to the maximum practical extent.  T.C.A. § 5-8-301(a). Counties are authorized to invest in instruments designated by general law as a safe temporary medium. These temporary investments must either be approved by the county legislative body, be in compliance with an investment policy adopted by the county legislative body, or be approved by an investment committee appointed by the county legislative body.  T.C.A. §§ 5-8-301, 5-8-302.

In counties that have not adopted the County Financial Management System of 1981, the county legislative body may create an investment committee to determine the investment of idle county funds from the statutory list of approved investments. The number of members on this committee and the mode of selection is according to resolution of the county legislative body. T.C.A. § 5-8-302.

In counties that have adopted the optional County Financial Management System of 1981, the county legislative body may establish an investment committee composed of five members appointed by the county legislative body. The members may or may not be members of the county legislative body. If the county has adopted the 1981 law, the county legislative body may choose to have the financial management committee perform the functions of the investment committee. The investment committee under the 1981 law establishes and approves policies and procedures for cash management and investing idle cash funds in the investments authorized by law and the director of finance has the authority to make the investments within the guidelines set by law and the committee's policies. T.C.A. §§ 5-21-105(e), 5-21-107(a). The organization of the investment committee in counties with a county charter or metropolitan government charter may differ from that provided by the general law.

There are three categories of idle county funds that may be invested: funds derived from bond proceeds; funds from the sale of assets, settlements, or other infrequent occurrences; and other idle county funds.  Under T.C.A. § 5-8-301, all three categories may be invested in any of the following manners:

1. Bonds, notes, or treasury bills of the U.S. as well as other obligations guaranteed by the U.S. or its agencies;

2. Deposits of funds into state and federally chartered banks and savings and loan associations, provided that these investments are properly secured;

3. Obligations of the United States or its agencies under a repurchase agreement for a shorter time than the maturity date of the security itself if the market value of the security itself is more than the amount of funds invested. Counties may invest in repurchase agreements only if the comptroller of the treasury or the comptroller's designee approves repurchase agreements as an authorized investment and if such investments are made in accordance with procedures established by the state funding board;

4. The state investment pool;

5. State bonds, if they have a rating of A or higher;

6. Nonconvertible debt securities of the following issuers provided such securities are rated in the highest category by at least two nationally recognized rating services:

• The Federal Home Loan Bank;
• The Federal National Mortgage Association;
• The Federal Farm Credit Bank;
• The federal home loan mortgage corporation; and
• Any other obligations that are guaranteed as to principal and interest by the United States or any of its agencies.

7. The county's own bonds or notes issued in accordance with Title 9, Chapter 21.  

Additionally, counties with a population of 20,000 to 150,000 may invest idle funds in prime commercial paper if it is rated in the highest category by at least two commercial paper rating services and the paper has a remaining maturity of 90 days or less. T.C.A. § 5-8-301.

Counties may invest funds held by them with a bank or savings and loan association with a branch in Tennessee under certain conditions, including FDIC insurance of the full amount of principal and interest or collateralization of amounts not so insured. T.C.A. § 9-1-118.  

There are other restrictions on the investment of specified county funds, as well as requirements for protection of county funds through proper collateralization of the investment.  T.C.A. § 5-8-301.  The advice of the state director of local finance, CTAS county government consultant, or county attorney will be helpful in determining available investment options, the correct procedures for making such investments, and the proper collateral to protect county investments.