According to an article on the Starting at 3 website, a preschool teacher in Kentucky must hold a Bachelor's degree in interdisciplinary early childhood education in order to be certified to teach preschool. This requirement took effect with the 2002-2003 academic year.
During the change in Kentucky preschool laws, the state issued letters of exemption for all teachers who were certified to teach kindergarten prior to 2003. This allowed those who were certified only to teach kindergarten to transition to preschool easily, without taking additional courses to get an early childhood or elementary certificate.
Preschool associate teachers who were hired prior to fall 2004, and working as a lead teacher in a preschool program, were allowed to stay in their position. However, this "grandfathering" process requires that the teacher be steadily employed as lead teacher. If the teacher is removed from this position for any length of time, then she would need an IECE certification to re-enter as a preschool teacher.
According to Kentucky state law 16:2:140, a probationary interdisciplinary early childhood certificate can be issued for a period of one year to a teacher who holds a kindergarten or special education certificate. If the teacher enrolls in and completes six credit hours each year toward the IECE certificate, the teacher may renew the probationary certificate for a period of no more than three years, so he can complete the requirements for the IECE certificate.