40 ILCS 5/7-151

Total and permanent disability benefits - Commencement and duration. Permanent disability benefits shall be payable:

(a) As of the date temporary disability benefits are exhausted;

(b) Once a month as of the end of each month;

(c) For less than a month in a fraction equal to that created by making the number of days of disability in the month the numerator and the number of the days in the month the denominator;

(d) To the beneficiary of a deceased employee for the unpaid amount accrued to the date of death;

(e) While total and permanent disability continues;

(f) For the period ending on the last day of the month which is the later of the following:

1. the month that the participating employee attains the age for a full Social Security old-age insurance benefit;

2. the month which is 5 years after the month the participating employee became disabled as provided in Section 7-146.