Utah Code § 49-11-503
§ 49-11-503. Rate of interest on redeposits, adjustments, and delinquent payments.
The rate of interest charged on redeposits of refunds, adjustments, or delinquent payments is the greater of: (1) the interest rate as determined under a formula approved by the board; or (2) the actuarial interest rate as of the preceding June 30.