Hawks L, et al. - This study was carried out to distinguish variations from 1998 to 2017 in unmet need for physician services among insured and uninsured adults aged 18 to 64 years in the United States. Between January 1, 1998, and December 31, 2017, a survey study applying 20 years of data, from the Centers for Disease Control and Prevention Behavioral Risk Factor Surveillance System to distinguish trends in the unmet requirements for physician and preventive services. The uninsurance decreased by 2.1 (95% CI, 1.6-2.5) percentage points (from 16.9% to 14.8%) among the adults aged 18 to 64 years in 1998 (n = 117,392) and in 2017 (n = 282,378) who responded to the Centers for Disease Control and Prevention Behavioral Risk Factors Surveillance System (mean age was 39.2 [95% CI, 39.0-39.3]; 50.3% were female; 65.9% were white).