Medicaid Expansion and the Opioid Overdose Crisis
The push to increase health coverage coincided with a dramatic increase in fatal overdoses in the United States -- but is it causal?
The opioid overdose epidemic in the U.S. continues unabated. In 2021, more than 80,000 deaths were recorded involving opioids — nearly four times more than in 2010. More recent provisional data suggests that things have only gotten worse over the last few years.
While the causes of the crisis are still debated, the basic story we’ve all heard goes something like this: Unscrupulous pharmaceutical companies downplayed the addictive risks of new opioid products like Oxycodone. Doctors over-prescribed these drugs without fully understanding their side effects. At the same time, illicit opioids (especially fentanyl) proliferated on American streets as the increasingly porous Southern border gave cartels easy access to the U.S. market, and declining economic prospects for many working-class Americans created robust demand for substances to blunt physical and emotional pain.
Other possible factors have been less widely discussed. For example, how does the largest expansion of health insurance coverage since the 1960s — driven by changes to Medicaid eligibility under the Affordable Care Act — fit into this picture?
There are plausible arguments on both sides. With more Americans visiting the doctor, Medicaid expansion may have helped fuel the opioid epidemic by making the use (and misuse) of prescription opioids more accessible. Figure 1, which shows total U.S. opioid deaths by year, is certainly suggestive. In 2014 and 2015, just as most states were adding millions of people to the Medicaid rolls, opioid deaths began to increase sharply. Moreover, expansion states tend to have higher drug overdose deaths per capita than non-expansion states.
But each of these points isn’t quite as compelling as it first appears. The vast majority of drug overdoses involve illicitly manufactured substances, which the Medicaid program obviously does not supply. (Of course, it’s possible that some people were first prescribed opioids through Medicaid, developed an addiction, and later succumbed to illicit formulations.)
As for the coincidental timing of Medicaid expansion and the uptick in opioid deaths around the country, it’s not clear which way causality runs. It could be that state policymakers adopted Medicaid expansion in an attempt to address the deepening opioid crises in their states.
Some have argued that the opioid crisis would be even worse if Medicaid expansion hadn’t expanded access to substance abuse treatment. This view is supported by research showing that Medicaid expansion increased admissions to mental health facilities and Medicaid-reimbursed prescriptions for medications used to treat mental illness. There is also evidence that Medicaid expansion reduced self-reported rates of psychological distress among those who gained coverage, at least in the short-run.
Several studies have attempted to measure Medicaid expansion’s effect on drug overdose deaths by comparing trends between expansion and non-expansion states. Some find that expansion was associated with slight reductions in overdose mortality, particularly in counties that saw the largest gains in insurance coverage due to expansion. Other research fails to detect any significant relationship between Medicaid expansion and opioid deaths.
Overall, although there are reasons to worry that Medicaid expansion has had negative unintended consequences, there isn’t much evidence that worsening the opioid crisis is one of them.