50 Ill. Adm. Code 4450.20
Prescribed Interest Rate
Section 4450.20 Prescribed
Interest Rate
This prescribed interest rate
shall only apply to a benefit (and all subsequent benefits) that was mistakenly
set too low if the first benefit is or was set on or after August 26, 2014. The
annual interest rate payable by an Article 3 or Article 4 pension fund is
prescribed at 1% when a lump sum payment is made by a pension fund to the
recipient pursuant to Sections 3-144.2(b) and 4-138.10(b) of the Illinois
Pension Code when a benefit was mistakenly set too low.