Tex. Health and Safety Code § 362.033: TERMS.

Bonds issued under this chapter must mature serially or in another manner not more than 40 years after they are issued. The bonds may:

(1) bear interest at a fixed, floating, or other type of rate, and be sold at public or private sale at a price or under terms that the issuer's governing body determines to be the most advantageous reasonably obtainable;

(2) be made callable before maturity at times and prices prescribed by the issuer's governing body;

(3) be in coupon form; and

(4) be registrable as to principal or as to principal and interest.

Acts 1989, 71st Leg., ch. 678, Sec. 1, eff. Sept. 1, 1989.