Of the households contacted, 82.2% participated in the 2009 survey. The response rate from participants exceeded 98% for the questions that produced the findings in this report, except for questions on income and race/ethnicity. Multiple imputations were performed on family‡ income and personal earnings data and hot-deck imputations were performed on race/ethnicity data to account for missing responses to these questions.§ NHIS data were adjusted for nonresponse and weighted to provide national estimates of insurance status, usual source of care, and care utilization; 95% confidence intervals were calculated, taking into account the survey's multistage probability sample design. The Wald test and logistic regression analyses were used to identify the statistical significance of differences in care utilization between persons who were continuously insured and those with either a 1-3 month gap in coverage in the preceding 12 months or with no health insurance for >12 months before the interview. Insurance status, usual source of care, and care utilization were examined by age group, sex, race/ethnicity, income level, and the highest level of education attained in the family. Data from the final release 2009 NHIS and early release NHIS data (i.e., compiled before final data editing and weighting) for the first quarter of 2010 were analyzed. Additional data from NHIS for 2006, 2007, and 2008 were used for comparison purposes.