Opioids are high-risk medications and a significant source of patient harm. Although prior research has shown that patients frequently share their prescribed medications with someone else, it remains uncertain whether individuals living in a household with a patient receiving prescription opioids are more likely to initiate prescription opioids. Using claims data from 2000 to 2014, this retrospective cohort study found that 12,695,280 individuals were exposed to prescription opioids and 6,359,639 to prescription nonsteroidal anti-inflammatory drugs (NSAIDs). The risk of opioid initiation in the following year among those exposed to prescription opioids was 11.83% and 11.11% among those exposed to prescription NSAIDs. The authors suggest that living in a home with a prescription opioid user may increase the risk of prescription opioid use among other household members. A PSNet perspective highlighted opioid overdose as a major patient safety problem.