With contributions from Judy Solomon, Senior Fellow

Medicaid coverage differs vastly from state to state and these differences matter to people’s health, economic security, and livelihood. When states gained the option to expand Medicaid under the Affordable Care Act in 2014, it provided an excellent opportunity to study the impact of this policy by comparing states that opted to expand with those that didn’t. Let’s talk more about what we’ve learned since then.

While all states saw coverage gains after the ACA’s major coverage provisions took effect in 2014, expansion states saw much larger drops in uninsured rates for low-income people. Plus, non-expansion states started with higher rates of uninsurance, so the gap in coverage between expansion and non-expansion states has widened. In 2013, 22.4 percent of people in expansion and 27.9 percent of people in non-expansion states were uninsured. By 2017, the share of uninsured in expansion states dropped to 10.9 percent while 20.6 percent of people in non-expansion states remained uninsured.

A review of the literature by the Kaiser Family Foundation (KFF) found that coverage also increased among vulnerable populations in expansion states relative to non-expansion states, including young adults; prescription drug users; people with substance use disorders; people with HIV; low-income adults who screened positive for depression; cancer patients; adults with a history of cardiovascular disease or two or more cardiovascular risk factors; women diagnosed with a gynecologic malignancy; veterans; parents; mothers; women of reproductive age (with and without children); children; lesbian, gay, and bisexual adults; low-income workers; low-educated adults; and justice-involved individuals.

On access to care, the KFF literature review documented improvements across a wide range of measures of access to care as well as use of a variety of medications and services. Some studies show that this improved access to care and use is leading to increases in diagnoses of a range of diseases and conditions and increases in the number of adults receiving consistent care for a chronic condition. Studies also show increased use of medication-assisted treatment (MAT) in expansion states.

Evidence of the measurable impact of expansion on health outcomes is increasing as more time is available to document expansion’s effects. Probably the most dramatic evidence of the positive impact expansion has had on health is a landmark study finding that Medicaid expansion is preventing thousands of premature deaths each year. The study found that Medicaid expansion saved the lives of at least 19,200 adults aged 55 to 64 over the four year period from 2014 to 2017. Conversely, 15,600 older adults died prematurely because of state decisions not to expand Medicaid.

Another recent study of southern states found that Medicaid expansion slowed the rates of health decline for low-income adults relevant to non-expansion states. A study comparing healthcare access among new mothers in Utah before the state’s expansion found that they experienced higher rates of Medicaid coverage loss and accessed fewer Medicaid-financed outpatient visits during the six months postpartum compared to new mothers in Colorado, an expansion state. The KFF literature review includes additional studies showing a positive impact on health outcomes and more research is likely forthcoming.

Some studies have found a difference in quality. For example, a study of care in federally qualified health centers found Medicaid expansion was associated with improved quality on four of eight measures examined: asthma treatment, Pap testing, body mass index assessment, and hypertension control. According to the KFF literature review, a few studies found that Medicaid expansion was associated with declines in hospital length of stay and increases in hospital discharges to rehabilitation facilities, and one study found an association between expansion and declines in mechanical ventilation rates among patients hospitalized for various conditions.

I’m not aware of any studies on the number of providers per capita, but most studies haven’t shown problems in provider capacity after expansion, although a few have. Many studies have shown increased use of primary care after expansion suggesting that the demand for additional care is being met.

Medicaid expansion has had a big impact on family financial security. Here’s a graphic from CBPP’s Medicaid chart book summarizing just some of the studies showing how expansion has improved financial security:

Moreover, Medicaid expansion enrollees in Michigan and Ohio reported that having coverage made it easier for them to work or seek employment.

There are positive implications for state budgets documented in numerous studies. According to the KFF literature review, analyses find effects on budget savings, revenue gains, and overall economic growth. Moreover, these positive effects occurred even though enrollment growth exceeded projections in some states. Plus, uncompensated care costs in expansion states fell by 55 percent, compared to only 18 percent in non-expansion states from 2013 to 2016.

Over time, it will be helpful to continue documenting the impact of expansion on health outcomes, state budgets, financial security, and other factors in the hope of persuading states that haven’t expanded to do so. The ability to show the impact on health outcomes will continue to grow the longer expansion is in place. It’s also important to show the impact restrictive waivers have on expansion. The work by Ben Sommers and his colleagues at Harvard comparing outcomes across states with waivers and those without has been invaluable in this regard. CMS has strengthened its requirements for evaluation of waivers, but there have been delays in seeing state evaluations, so the work of outside researchers has been essential in showing the impact of restrictions such as work requirements and premiums on coverage.

Despite the evidence of expansion’s benefits, the Trump Administration continues its efforts to undermine its success. Most recently, it released guidance allowing states unprecedented authority to charge premiums and co-payments, loosen beneficiary protections in managed care, put limits on prescription drugs, and impose work requirements in exchange for agreeing to capped funding.

It also proposed a rule that would significantly restrict how states fund their share of Medicaid costs. Most states pay their share of Medicaid costs through a combination of three sources: (1) general revenue, (2) taxes on providers, and (3) funds transferred from or certified by state and local government health care providers (called intergovernmental transfers, or IGTs, and certified public expenditures, or CPEs, respectively). The rule would force many states to curtail their use of provider taxes, IGTs, and CPEs. If states couldn’t make up the funds, they would have to cut benefits and eligibility as well as provider payments, particularly payments to hospitals and nursing homes.

Moreover, a proposed eligibility rule is expected to be issued this spring that will increase paperwork for beneficiaries at application and renewal, which will likely lead to eligible people losing coverage or remaining uninsured.

The research on the positive impacts of expansion has been extremely helpful in moving more states to expand and keeping expansion states from adopting restrictive waivers, so continuing support for research is a major need. At the state and local level, consumer advocacy groups need ongoing support to engage in efforts to promote expansion, defend it from restrictions, and to implement it in a way that ensures eligible people can enroll and stay enrolled.

In terms of staying connected, KFF is a great resource to track what’s happening on waivers and Medicaid more broadly. CBPP and other national groups, like Community Catalyst and the Georgetown Center for Children and Families, work closely with state groups and can be a resource to help make connections in particular states and localities.