Expanding Medicaid expands substance use help for the underserved

The Senate convened a hearing in January 2018 to explore the theory that the expansion of Medicaid (as part of the Affordable Care Act) has fueled the opioid overdose epidemic afflicting the nation. This commentary took an empirical look at that claim, and what we know about Medicaid’s potential role in helping to address the epidemic.


Expanding access to medical health insurance in turn increases the opportunities to obtain prescribed controlled substances including opioids.  However, having health insurance also increases access to substance use treatment as well as non-opioid treatments for pain, and other conditions related to substance misuse like mood and anxiety disorders.

Medicaid is a joint federally and state-funded insurance, administered by state governments that serves those meeting income-based eligibility.  The income guidelines were expanded as part of the Affordable Care Act, allowing each state to chose whether to expand Medicaid (given the increased federal funding of part of the cost).  This editorial examined the risks vs benefits of Medicaid expansion, comparing increased opioid prescribing as compared to increased medication-assisted treatment for opioid use disorder.


This editorial by Keith Humphreys is primarily focused on two studies of the consequences of Medicaid enrollment.


The first is a study in the same issue of the American Journal of Public Health that analyzed Medicaid enrollment and reimbursement data from 2011-2016 across all 50 states.  This naturalistic study by Sharp et al. quantified opioid prescribing per Medicaid enrollee and compared the average prescribing in states that had participated versus not participated in the Medicaid expansion of the Affordable Care Act.  Likewise, they compared prescribing of buprenorphine (Suboxone) and naltrexone using the same parameter.

The second study discussed the randomized enrollment of participants into Medicaid as part of the Oregon Health Insurance Experiment and the number of opioid prescriptions they received as compared to eligible applicants not randomized to receive Medicaid.


Medicaid expansion significantly increases access to medication assisted treatment for opioid use disorder (as per Sharp et al) – Rates of Medicaid-reimbursed buprenorphine and naltrexone prescribing increased 200% on a per-enrollee basis in states opting for Medicaid expansion versus only a 50% increase in states opting out of the Medicaid expansion as part of the Affordable Care Act.

Medicaid enrollment did not measurably increase enrollees’ access to or use of prescription opioidsBoth studies discussed in this Editorial reach similar conclusions using complementary study designs.  Opioid prescriptions did not increase for participants randomized to enroll in Medicaid versus other eligible applicants not granted Medicaid.  Opioid prescribing did not differ statistically between states opting for Medicaid expansion versus those that did not expand Medicaid, although opioid prescriptions did increase on a per-enrollee basis during the 2011-2016 period analyzed in both groups.

Medicaid increases access to treatment for conditions comorbid with substance use disorder – the Oregon Health Insurance Experiment showed significantly decreased depression rates after being randomized to receive Medicaid.


Short-comings of the current Medicaid system:

  1. Only a small minority of states provide all levels of care recommended for opioid use disorder (standard outpatient, intensive outpatient, residential inpatient and medical inpatient), with outpatient services primarily centered on medication-assisted treatment at the expense of psychotherapy.
  2. Reimbursement rates are lower than for other private or public insurance programs, decreasing access to care.
  3. 17 states have chosen not to expand access to Medicaid such that Medicaid can only be accessed by those with very limited income.



Access to expanded Medicaid coverage increases access to medications for opioid use disorder far more than it increases access to opioids prescribed to treat pain and is thus poised to serve an important role in limiting the suffering associated with the current opioid crisis.  This is in contrast to some politicians’ concerns to the contrary.  That being said, enhancing and expanding Medicaid further could increase the ability of those most under-resourced to access effective treatments for opioid use disorder.

  1. The two studies referenced each had limitations.
    • Sharp et al was a naturalistic study which pooled state-wide data into two large groupings (the 33 states adopting Medicaid expansion vs the 17 states that did not) meaning there are multiple confounders for the results (eg. the states not choosing to expand Medicaid might already have a lower level of social services than those states that did not).
    • Baicker et al was based on randomized data (eligible applicants were randomized to receive Medicaid benefits) but the opioid prescribing rates were based on self-report.
  2. This editorial was written in a political climate expressing strong opposition to Medicaid expansion, thus likely limiting a fully balanced discussion of possible significant limitations of the Medicaid system as it stands.


  • For individuals & families seeking recovery: Medicaid is accessible to those having modified adjusted gross income levels at or slightly above the federal poverty level.  Those struggling with significant substance use may have difficulty maintaining employment or having access to employer-sponsored medical insurance. Since the income requirements for Medicaid are based on recent earnings, many with greater than a year of lost employment may be eligible.  Details for state-specific Medicaid eligibility can be found here.  Medicaid will cover some inpatient medical and residential care, as well as standard outpatient treatment.  Due to the low reimbursement rates, many private providers do not accept Medicaid, leading to increased wait times for Medicaid providers.
  • For scientists: The Affordable Care Act included many internal randomized trials of implementation to assess innovation and quality measures, such as the Oregon Health Insurance Experiment referenced in this Editorial.  There is significant, likely high quality data in these implementation trials which were not spear-headed by researchers suggesting that the data is likely under-examined from a scientific perspective.
  • For policy makers: Given the current political controversies around Medicaid expansion, the airing of these concerns provides a forum in which to present data in support of the effectiveness of the Medicaid medical insurance system and the rationale for its expansion.  However, the Medicaid system faces significant challenges.  As part of the expansion or the re-examination of Medicaid policies, policy makers might compare the Medicaid fee-for-service model with the medical home model as proposed for substance use recovery as proposed by a number of the industry leaders in the field.  This is an alternative payment model focused around an Addiction Recovery Medical Home that might perhaps allow Medicaid dollars to go further in the pursuit of effective substance use recovery.
  • For treatment professionals and treatment systems: As uninsured patients often present to emergency rooms (or are brought there by law enforcement), setting aside the resources to enroll those patients in Medicaid while on hospital grounds may lead to increased access to substance use care once those patients are ready.


Humphreys K. How Medicaid can strengthen the national response to the opioid epidemic [editorial]. AJPH. 2018;108(5):589-590. Epub April 4, 2018.


**Note: The study author, Dr. Keith Humphreys, is a Advisory Board Member of the Recovery Research Institute. The study author had no role in the writing of this summary.