34 Tex. Admin. Code § 25.64
A crediting fee of 8.0% compounded annually shall be charged for the purchase of credit from the end of the year in which the member was first eligible to purchase the credit until payment for the credit is received. The date of first eligibility to purchase credit shall be the latest of the following:
Source Note:The provisions of this §25.64 adopted to be effective January 1, 1976; amended to be effective September 11, 1977, 2 TexReg 3279; amended to be effective October 1, 1982, 7 TexReg 3366; amended to be effective June 15, 1999, 24 TexReg 4455.