Objective: Several studies have shown that Adult ADHD presents differently in younger and older adults. We sought to assess the difference in care between these two groups using previously identified quality measures (QMs). Methods: Using electronic health record data, we matched a younger group of ADHD patients to an older group. We then assessed the achievement of the QMs using probit models with and without interaction terms. Results: The majority of QMs shown an increase in achievement for both groups over time. However, significant differences in quality of care between younger and older adult ADHD patients persisted. By the end of the study period, with the exception of three QMs, younger patients achieved the QMs more. Conclusion: While, in general, the quality of care for adult ADHD increased from 2010 to 2020, there were still differences in care between younger and older adult ADHD patients.