Preschool expenses can be applied to the child and dependent care credit. See the following excerpt from IRS Publication 503:
Education
. Expenses for a child in nursery school, preschool, or similar programs for children below the level of kindergarten are expenses for care.
Expenses to attend kindergarten or a higher grade aren't expenses for care. Don't use these expenses to figure your credit.
However, expenses for before- or after-school care of a child in kindergarten or a higher grade may be expenses for care.
Summer school and tutoring programs aren't for care.