Actually across the board it should be 6 months for formula feeding or supplementing mom's and 12 months for breastfeeding mom's.
"The WIC Program is designed to serve certain categories of women, infants, and children. Therefore, the following individuals are considered categorically eligible for WIC:
Women -- pregnant (during pregnancy and up to 6 weeks
after the birth of an infant or the end of the
-- postpartum (up to six months after the birth of
the infant or the end of the pregnancy)
-- breastfeeding (up to the infant's first birthday)
Infants (up to the infant's first birthday)
Children (up to the child's fifth birthday)"
WIC eligibility guidelines http://www.fns.usda.gov/wic/howtoapply/eligibilityrequirements.htm
at 10:07 AM on Jul. 24, 2010