(a) Unless this subtitle expressly specifies another rate of interest, for periods after December 31, 2008, the rate of interest is five percent compounded annually, plus any other amounts the board of trustees is expressly authorized to provide. Notwithstanding any other provision in this chapter, the interest credited to a member's individual account in a calendar year may not be less than five percent.
(b) Effective as of December 31 of each year, the board of trustees shall credit interest on the accumulated contributions in a member's individual account as of January 1 of that year in accordance with Subsection (a) and Section 855.306.