Ill. Admin. Code tit. 50, § 4440.50
a) An eligible rollover distribution is any distribution of all or any portion of the balance to the credit of the distributee, except that an eligible rollover distribution does not include:
3) the portion of any distribution that is not includible in gross income; and
b) Effective:
1) January 1, 2002, a portion of a distribution will not fail to be an eligible rollover distribution merely because the portion consists of after-tax employee contributions that are not includible in gross income. However, that portion may be transferred only:
2) on or after January 1, 2007: