The U.S. Centers for Disease Control and Prevention officially declared an opioid epidemic in 2011, and the problem has continued to grow; President Trump declared it a public health emergency in October 2017. Between 2000 and 2015, more than half a million people died from opioid overdose, half of which were from prescription (as opposed to illicit) drugs. In 2016, opioid overdose killed 91 Americans every day, more than 64,000 people by year’s end—almost double the deaths in 2015. Deaths from fentanyl, a synthetic opioid that is similar to morphine but 50 to 100 times more powerful, rose 540 percent in three years. In addition to rising overdose deaths among opioid users, the number of babies born with symptoms of opiate withdrawal due to maternal opioid use during pregnancy also continues to climb. Although substance abuse and addiction are complex social problems experienced by people from all walks of life, several studies suggest that opioid abuse and socioeconomic disadvantage are often intertwined. This brief draws the contours of the crisis, explores associations of low education and income with opioid misuse, and identifies some research gaps.