Functional limitations and disability declined in the US during the 1980s and 1990s, but reports of early 21st century trends are mixed. Whether educational inequalities in functioning increased or decreased is also poorly understood. Given the importance of disability for productivity, independent living, and health care costs, these trends are critical to US social and health policies. We examine recent trends in functional limitations and disability among women and men aged 45-64. Using 2000-2015 National Health Interview Surveys data on over 155,000 respondents, semiparametric and logistic regression models visualize and test functioning trends by education. Among women and men with at least a college degree, there was no change in disability and mild increase in limitations over time. All other education levels experienced significant increases in functioning problems ranging from 18% higher odds of functional limitations in 2015 compared to 2000 among men with some college to about 80% increase in the odds of disability among women and men with less than high school education. The similar trends for both genders suggest common underlying causes, possibly including the worsening economic well-being of middle- and working-class families. The pervasive growth of functioning problems is a cause for concern that necessitates further scholarly investigation.