Past literature has found links between higher opioid use and local economic conditions for people enrolled in public health programs, but there has been little discussion of whether this relationship occurs among the privately insured. Using HCCI claims data and county level income data from the US Census Bureau, we examined how a county's median household income relates to long-term opioid use among the county's working adult population with private health insurance in 2015. In analyzing over 1,500 counties, we found that employed adults (over the age of 18) living in counties with lower median incomes had greater rates of long-term opioid use (having filled at least 6 prescriptions for opioids) compared to employed adults in higher income counties. Nationally, 2.4% of employed adults with private health insurance were long-term opioid users in 2015. In the lowest median income counties ($30k or less), 4.9% of the employed adult population were long-term opioid users, with some counties having rates as high as 15.8%. In contrast, just 1.3% of the same population in the highest median income counties ($100k or more) were long-term opioid users and the highest rate in these counties was 2.3%.