40 ILCS 5/7-109.5

"Tier 2 regular employee" means a person who first becomes a participant under this Article on or after January 1, 2011 and is not a Tier 1 regular employee. Notwithstanding anything contrary in this Section, "Tier 2 regular employee" does not include a participant or annuitant who is eligible to have his or her annuity calculated under Section 7-142.1 or a person who elected to establish alternative credits by electing in writing after January 1, 2011, but before August 8, 2011, under Section 7-145.1 of this Code.