The goal of this research is to evaluate the impact of these two developments in the health insurance market -- HSA-HDHPs and PDLs -- on medication use and clinical outcomes for adults and children with asthma. To do this, tteh investigators will first conduct in-depth interviews with patients with asthma and parents of children with asthma who have HDHPs and traditional plans. Interviews will collect patient-reported data on how patients and their families navigate their insurance plan and make health care decisions when faced with OOP costs. Findings from the interviews will inform analyses of data from a large national health plan from 2004-2017. Investigators will select adults and children with asthma whose employer switched them from traditional plans to HSA-HDHPs with or without a PDL. Analyses will examine changes in asthma medication use, emergency department (ED) visits, hospitalizations, and OOP costs before and after changing plans compared to similar patients who did not switch to a HSA-HDHP. The study aims to: 1) understand health care decision making and experiences of families with asthma with HDHPs; 2) examine the impact of HSA-HDHPs with and without PDLs on use of asthma medications and asthma-related ED visits and hospitalizations; 3) examine the extent to which the response to HSA-HDHPs and PDLs is affected by the presence of other family members with asthma or other chronic conditions; 4) examine the impact of HSA-HDHPs with and without PDLs on OOP costs for families.