Objectives. To determine the impact of data disaggregation on the ability to identify health disparities and needs for future research for Filipino, Vietnamese, Chinese, Japanese, and Korean adults in California.Methods. Using available data from the 2011-2017 California Health Interview Survey, we conducted bivariate and multivariable analyses to assess disparities in health conditions, outcomes, and service access compared with non-Hispanic Whites for Asians as an overall group and for each individual subgroup.Results. As an aggregate category, Asians appeared healthier than did non-Hispanic Whites on most indicators. However, every Asian subgroup had at least 1 disparity disguised by aggregation. Filipinos had the most disparities, with higher prevalence of fair or poor health, being obese or overweight, and having high blood pressure, diabetes, or asthma compared with non-Hispanic Whites (P < .05) in multivariable analyses.Conclusions. Failure to disaggregate health data for individual Asian subgroups disguises disparities and leads to inaccurate conclusions about needs for interventions and research.