Objective: To examine whether and how different kinds of access to care (financial, potential, and realized) predict parent-report child primary care experiences in an urban community sample., Data Sources/study Setting: A prospective cohort study was performed. Baseline survey data were collected (67 percent response rate) from 3,406 parents of kindergarten through sixth grade students in a large urban school district in California during the 1999-2000 school year. A 1-year survey (80.4 percent response rate) resulted in a final sample of 2,738., Study Design: Data were analyzed using multiple regression models with robust estimation. The dependent variable was Time 2 parent reports of primary care experiences, assessed via the Parents' Perceptions of Primary Care (P3C) measure. The independent variables were financial access (insurance status), potential access (presence of a regular source of care), and realized access (foregone care), controlling for child and family characteristics (race/ethnicity, parent's language, mother's education level, and child chronic health condition status) and baseline P3C scores., Data Collection: Data were collected by mail, telephone, and in person in English, Spanish, Vietnamese, and Tagalog., Principal Findings: Controlling for baseline P3C scores and child and family characteristics, having no health insurance at both baseline and Time 2 was associated with a 6.2-point lower Time 2 P3C score, relative to having had health insurance at both time points. Having a regular provider at Time 2 (either always having had one or gaining one during the year) was associated with, on average, a 10-point higher Time 2 P3C score, compared to children without a regular provider (either never having had one or losing one during the year). Episodes of foregone care during the year were associated with 10.7 points lower Time 2 P3C scores, relative to children whose parents did not report foregone care. Similar relationships were found between all three measures of access to care and each of the sub-domain measures of primary care experience., Conclusions: Financial, potential, and realized access to care are associated prospectively with the full range of primary care experiences--comprehensiveness, communication, coordination, and contextual knowledge--beyond continuity and accessibility. Access to a regular source of care and to needed care are each associated with larger effects on primary care experiences than is the presence of health insurance. Gaining insurance or a regular source of care results in primary care experiences similar to always having had these, while losing a regular source of care has a more immediate effect than losing insurance on primary care experiences.