Ala. Code § 11-47-231

The bonds of an authority shall be legal investments in which the state and its agencies and instrumentalities, all counties, municipalities, and other political subdivisions of the state and public corporations organized under the laws thereof, all insurance companies and associations and other persons carrying on an insurance business, all banks, savings banks, savings and loan associations, trust companies, credit unions, and investments companies of any kind, all administrators, guardians, executors, trustees and other fiduciaries, and all other persons whosoever are now or may hereafter be authorized to invest in bonds or other obligations of the state, may properly and legally invest funds in their control or belonging to them.