“Out-of-Pocket Spending for Retail Prescribed Drugs by Age and Type of Prescription Drug Coverage, 2009 to 2018,” by William A. Carroll, G. Edward Carroll, and Steven C. Hill (Medical Expenditure Panel Survey Statistical Brief No. 532, December 2020, .pdf and HTML format, 11p.).
meps.ahrq.gov/mepsweb/data_stats/Pub_ProdResults_Details.jsp?pt=Statistical+Brief&opt=2&id=1271
