38 percent of children in nonparental care have more than one regular child care arrangement each week. Most of these children are in two arrangements. Low-income and higher-income families are equally likely to use multiple arrangements. Three- and four-year-olds were more than three times as likely to be in three or more arrangements than children younger than three. Of those children that use two or more arrangements, two-thirds are in a combination of formal (centers and family child care homes) and informal (relatives and baby-sitters) arrangements.