Affordable Care Act Insurance Expansion Research Articles

The Impact of the Affordable Care Act Insurance Expansions on Opioid-Related Emergency Department Visits

The Impact of the Affordable Care Act Insurance Expansions on Opioid-Related Emergency Department Visits

Effects of the Affordable Care Act Insurance Expansions on Health Care Coverage, Access, and Health Status of 50-64-Year-Old Adults: Evidence From the First Six Years.

Individuals aged 50-64 face a higher burden of chronic conditions and an increased probability of insurance coverage loss, making them particularly vulnerable to limited access than younger adults. This study examines the effects of the Affordable Care Act (ACA) insurance expansions, including both Medicaid eligibility and other expansions, on health care coverage, access, and health status of adults aged 50-64 years over 6years since the initial expansions in 2014. Using a triple difference-in-difference-in-differences model and nationally representative data, we find that the ACA increased private insurance and Medicaid coverage. There is evidence of improved access based on having a personal provider, completing a routine checkup, and reducing forgoing medical care due to cost. There is little evidence for the effects on self-reported health outcomes. Findings suggest that coverage expansions have improved access to care but have thus far not had discernible and consistent effects on self-reported health for 50-64-year-olds.

The Impact of the Affordable Care Act Insurance Expansions on Opioid‐Related Emergency Department Visits

Research ObjectiveAmid rising opioid‐related deaths and hospital use, the 2010 Patient Protection and Affordable Care Act (ACA) was signed into law, with the central coverage provisions implemented in 2014. Because lack of health insurance is a barrier to opioid use disorder treatment, and because opioid use disorder treatment can prevent opioid‐related emergency department (ED) visits, we explore the impact of ACA Medicaid expansion and ACA marketplace insurance expansions on opioid‐related ED visits.Study DesignWe use ZIP Code‐level ED utilization data from the 2010–2018 Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases (SID) and State Emergency Department Databases (SEDD) for 29 states, while also accounting for the implementation of relevant state‐level policies using information from sources such as the Kaiser Family Foundation and the Prescription Drug Abuse Policy System. We control for area‐level sociodemographic information using from sources such as the Bureau of Labor Statistics and the Census. We use a difference‐in‐differences (DD) estimation strategy as well as a within‐state dose–response, difference‐in‐differences‐in‐differences (DDD) model based on pre‐ACA uninsurance levels to estimate impacts of the ACA in each of the five years following the 2014 insurance expansions.Population StudiedWe use data on ED visits among nonelderly adults from 2010–2018 for 17 states that adopted Medicaid expansion on January 1, 2014 (Arizona, California, Connecticut, Hawaii, Illinois, Iowa, Kentucky, Maryland, Massachusetts, Minnesota, Nevada, New Jersey, New York, North Dakota, Ohio, Rhode Island, and Vermont) and 12 states that did not implement Medicaid expansion during the study period (Florida, Georgia, Kansas, Maine, Missouri, Nebraska, North Carolina, South Carolina, South Dakota, Tennessee, Utah, and Wisconsin).Principal FindingsWe find that ACA coverage expansions reduced opioid‐related ED visits, but the effect varies over time. Relative to non‐expansion states, opioid‐related ED visit rates in expansion states remain the same or decrease slightly in the first three years after Medicaid expansion (2014–2016). A more marked decline emerges in the fourth and fifth years (2017–2018) after Medicaid expansion. Both DD and DDD results show strong evidence that the impact of ACA insurance expansions on opioid‐related ED visits grew over time.ConclusionsWe find that ACA insurance expansions reduced opioid‐related ED visit rates, with an effect that grows over time. As time from ACA implementation increases, aggregate effects of lower out‐of‐pocket prices, improved access to care, and supply responses would most likely produce reductions in opioid‐related ED visits, which we find in the fourth and fifth year after ACA implementation. These dynamics help explain why studies examining shorter post‐ACA periods or that were unable to estimate time‐varying impacts did not detect significant impacts of coverage expansions on opioid‐related ED visits.Implications for Policy or PracticeThere are likely to be lags between the time when an individual with substance use disorder (or at risk of developing the disorder) gains coverage, the time when the individual accesses treatment, and consequent reductions in ED visits. Our findings suggest that there are similarly important dynamics in the impact of insurance expansion on opioid‐related ED visits.

How Have ACA Insurance Expansions Affected Health Outcomes? Findings From The Literature.

A growing body of literature examining the effects of the Affordable Care Act (ACA) on nonelderly adults provides promising evidence of improvements in health outcomes through insurance expansions. Our review of forty-three studies that employed a quasi-experimental research design found encouraging evidence of improvements in health status, chronic disease, maternal and neonatal health, and mortality, with some findings corroborated by multiple studies. Some studies further suggested that the beneficial effects have grown over time and thus may continue to grow if the ACA insurance expansions remain in force. However, not all studies reported a significant positive relationship between ACA provisions that expanded insurance coverage and health status. We highlight the challenges facing researchers, including the importance of nonmedical factors in determining individual health and the use of outcome data predominantly drawn from self-reports. In closing, we identify opportunities to enhance researchers' understanding of the relationship between the ACA insurance expansions and health outcomes using new data sources, including electronic health records.

Association of Ambulance Use in New York City With the Implementation of the Patient Protection and Affordable Care Act

Expanding insurance coverage may be associated with overuse of medical care because newly insured patients are insulated from having to pay the full cost. To examine the use of ambulance transport before and after the rollout of the Patient Protection and Affordable Care Act (ACA) in New York City (NYC), New York. In this case-control study, the volume of ambulance dispatches in NYC for minor injuries before and after the rollout of the ACA was examined. Data were drawn from a census of all ambulance dispatches in NYC between January 1, 2013, and July 31, 2016. Ambulance dispatches for more severe injuries, which are more difficult to characterize as unnecessary, were used as the control group. Analyses were conducted from August 17, 2017, to May, 10, 2019. The main outcome was the number of ambulance dispatches for minor injuries, defined per month per dispatch zone. The implementation of the ACA was measured using an indicator variable of 1 for dispatches starting January 1, 2014, and 0 for dispatches before January 1, 2014. The number of ambulance dispatches for injuries and major injuries was used to account for secular trends. Injury severity was classified by the dispatchers based on information from the 911 callers with a severity score on a scale of 1 to 8, where 1 is the most severe; minor injuries had a score of 7; injuries, 5; and major injuries, 3. There were 4 787 180 ambulance dispatches in NYC during the study. After the 2014 expansion of insurance coverage under the ACA, there was an increase in ambulance dispatches for minor injuries compared with dispatches for more severe injuries. Compared with the preimplementation mean (SD) of 20.75 (14.24) minor injury dispatches per dispatch zone per month, there were 7.71 (95% CI, 1.23-14.19) additional minor injury dispatches per dispatch zone per month compared with dispatches for other types of injuries, an increase of 37.2%. Given that NYC has 31 dispatch zones, this increase is equivalent to approximately 239 additional dispatches per month or 2868 additional dispatches per year for minor injuries. There was a significant increase in use of ambulance transport for minor injuries in NYC after the ACA insurance expansion, suggesting that the change in health insurance structure was associated with increased use of emergency medical services in nonemergent situations. Future reforms to the US health insurance system should take into account the potential for increased use of emergency medical services in nonemergent situations, which the literature suggests may lead to congestion and slower response times.

Women's Affordability, Access, and Preventive Care After the Affordable Care Act

Women historically have had difficulty maintaining health insurance, obtaining preventive care, and affording care. The objectives of this study were to describe changes in insurance affordability, healthcare access, and preventive care for women of different income levels after implementation of the Affordable Care Act. This was a difference-in-differences analysis of data about U.S. women aged 19-64years from the National Health Interview Survey. This study examined self-reported insurance affordability, access to health care, and preventive services. Changes before (2010-2013) and after (2014-2017) the Affordable Care Act insurance expansions were compared by income (≤138% federal poverty level vs≥400% federal poverty level). Multivariate difference-in-differences analyses adjusting for demographics were expressed as risk differences. The sample represented an estimated 41,106,929 women. After the Affordable Care Act, women with incomes ≤138% federal poverty level, compared with ≥400% federal poverty level, had less difficulty finding affordable insurance (adjusted difference-in-differences: -27.18, 95% CI= -36.37, -18.00); were more likely to have seen/talked to a doctor in 12 months (adjusted difference-in-differences: 3.08, 95% CI=1.29, 4.87), had blood pressure screening (adjusted difference-in-differences: 3.27, 95% CI=1.94, 4.60), cholesterol screening (adjusted difference-in-differences: 5.05, 95% CI=2.45, 7.64), and mammograms (adjusted difference-in-differences: 6.87, 95% CI=3.94, 9.79). After implementation of the Affordable Care Act, women in all income groups, especially the lowest, reported greater affordability of coverage, access to health care, and receipt of preventive services. Efforts to alter the Affordable Care Act should consider the impact of policy changes on women's health and preventive care.

Impact of Affordable Care Act Insurance Expansion on Pre-Hospital Access to Care: Changes in Adult Perforated Appendix Admission Rates after Medicaid Expansion and the Dependent Coverage Provision

The Affordable Care Act (ACA) changed the landscape of insurance coverage, allowing young adults to remain on their parents' insurance until age 26 (Dependent Coverage Provision [DCP]) and states to optionally expand Medicaid up to 133% of the federal poverty level. Although both improved insurance coverage, little is known about the ACA's impact on observed receipt of timely access to acute care. The objective of this study was to compare changes in insurance coverage and perforation rates among hospitalized adults with acute appendicitis "after vs before" Medicaid expansion and the DCP using an Agency for Healthcare Research and Quality (AHRQ)-certified metric designed to measure pre-hospital access to care. We performed a quasi-experimental, difference-in-difference (DID) analysis of 2008-2015 state-level inpatient claims. Adults, aged 19 to 64, in expansion states experienced an absolute 7.7 percentage point decline in uninsured (95% CI 7.5 to 7.9) after Medicaid expansion compared with nonexpansion states. This coincided with a 5.4 percentage point drop in admissions for perforated appendicitis (95% CI 5.0 to 5.8) that was most pronounced among young adults, aged 26 to 34, just age-ineligible for the DCP (DID: 11.5 percentage points). Medicaid expansion insurance changes were 4.1 times larger than those encountered under the DCP (DID: 1.9). They affected all population subgroups and significantly reduced access-related disparities in race/ethnicity and lower-income communities. Although both Medicaid expansion and the DCP were associated with significant insurance gains, those attributable to the DCP were more concentrated among more privileged patients. Despite this trend, both policies resulted in larger reductions in perforation rates for historically uninsured and underserved groups. Reductions in uninsured after Medicaid expansion and the DCP were associated with significant reductions in perforated appendix admission rates. Improvements in access to acute surgical care suggest that maintained/continued insurance expansion could lead to fewer delays, better patient outcomes, and reductions in disparities among the most at-risk populations.

Impact of Affordable Care Act Insurance Expansion on Access to Care: Changes in Perforated Appendix Rates among Adults after Medicaid Expansion and the Dependent Coverage Provision

Impact of Affordable Care Act Insurance Expansion on Access to Care: Changes in Perforated Appendix Rates among Adults after Medicaid Expansion and the Dependent Coverage Provision

Family Planning Confidential: A Qualitative Research Study on the Implications of the Affordable Care Act

PurposeA cornerstone of the Title X program is guaranteed access to confidential family planning services regardless of patients’ ability to pay. This is particularly important for adolescents and young adults. The Patient Protection and Affordable Care Act (ACA) expanded health insurance access for thousands of individuals. But, billing third-party payers for family planning services can result in the generation of explanations of benefits and other communications to the policy holder that may compromise confidentiality for covered dependents. MethodsThe research team facilitated 12 focus groups with 62 Title X clients in 5 states and conducted interviews with 91 health center key informants in 10 states. Transcripts were coded using NVivo version 10.0. Researchers used deductive coding and grounded theory to search for themes. ResultsClients expressed confusion about the difference between confidential services from their health center versus confidential communications from their health insurance plan. Health center staff also highlighted confidentiality issues that may arise from ACA insurance expansion and revealed that clients overall do not understand how health insurance works, particularly younger clients and those that were newly covered under the ACA. ConclusionsMany Title X supported health centers will continue not to bill insurance if there are concerns regarding confidentiality, especially with their adolescent and young adult clients. Despite additional revenue sources that have emerged since the passage of the ACA, Title X funding may remain critical for clients who need safe, affordable, and confidential care.

Inpatient Trauma Mortality after Implementation of the Affordable Care Act in Illinois.

IntroductionIllinois hospitals have experienced a marked decrease in the number of uninsured patients after implementation of the Affordable Care Act (ACA). However, the full impact of health insurance expansion on trauma mortality is still unknown. The objective of this study was to determine the impact of ACA insurance expansion on trauma patients hospitalized in Illinois.MethodsWe performed a retrospective cohort study of 87,001 trauma inpatients from third quarter 2010 through second quarter 2015, which spans the implementation of the ACA in Illinois. We examined the effects of insurance expansion on trauma mortality using multivariable Poisson regression.ResultsThere was no significant difference in mortality comparing the post-ACA period to the pre-ACA period incident rate ratio (IRR)=1.05 (95% confidence interval [CI] [0.93–1.17]). However, mortality was significantly higher among the uninsured in the post-ACA period when compared with the pre-ACA uninsured population IRR=1.46 (95% CI [1.14–1.88]).ConclusionWhile the ACA has reduced the number of uninsured trauma patients in Illinois, we found no significant decrease in inpatient trauma mortality. However, the group that remains uninsured after ACA implementation appears to be particularly vulnerable. This group should be studied in order to reduce disparate outcomes after trauma.

Tobacco Control, Medicaid Coverage, and the Demand for Smoking Cessation Drugs

To date, there has been limited research on what drives demand for smoking cessation products, especially pharmaceutical interventions. In this study, we use the near-universe of smoking cessation pharmaceutical prescriptions (1999–2012) to estimate the demand response to several anti-smoking policies (cigarette taxes, smoking bans, and Medicaid benefits). Our differences-in-differences estimates suggest an increase of 20 prescriptions per 10,000 persons following the introduction of Medicaid coverage, while taxes and bans demonstrate a less clear impact at the state level. Consumers appear sensitive to out-of-pocket cessation medication costs, which has relevance to recent Affordable Care Act insurance expansions and coverage regulations.

Using hospital use trends to improve transitional care

BackgroundThis study evaluates the Northwestern Medicine Group Transitional Care clinic (NMG-TC), which transitions patients from an urban hospital to primary care at partner community clinics. We evaluate change over the 55 month study period in emergency department, observation or inpatient use within 90 days of an initial NMG-TC visit. MethodsElectronic health records were used to determine patient demographic, insurance and clinical characteristics, including inflation-adjusted total hospital charges in the 90 days prior and the 90 days after an initial NMG-TC visit. Multiple logistic regression was used to estimate the likelihood of any 90-day post-NMG-TC visit hospital use, controlled for the simultaneous effects of patient characteristics and pre-visit hospital use level. ResultsThere were 3318 patients with 90-day follow-up of whom 28.5% had 90 day post-visit hospital encounters. Patients with cancer, infectious disease or pain diagnoses at the time of a NMG-TC visit had the highest 90-day post-visit hospital use. The level of pre-NMG-TC visit hospital charges, the number of NMG-TC visit diagnostic categories and the number of NMG-TC visits all showed a sharply graded effect on subsequent hospital use. Patients with a first NMG-TC visit in the last nine months of the study (2015–2016) had a 38% lower likelihood of any 90-day hospital use (OR = 0.62, 95% CI = 0.45–0.84) as compared to patients seen in 2011–2012. Conclusion and implicationsReduced post-visit hospital use is likely related to increased clinic resources, Affordable Care Act insurance expansions, and improved clinical and community social service expertise. Level of evidenceCohort study, Level 2

Emergency Department Use across 88 Small Areas after Affordable Care Act Implementation in Illinois

IntroductionThis study analyzes changes in hospital emergency department (ED) visit rates before and after the 2014 Affordable Care Act (ACA) insurance expansions in Illinois. We compare the association between population insurance status change and ED visit rate change between a 24-month (2012–2013) pre-ACA period and a 24-month post-ACA (2014–2015) period across 88 socioeconomically diverse areas of Illinois.MethodsWe used annual American Community Survey estimates for 2012–2015 to obtain insurance status changes for uninsured, private, Medicaid, and Medicare (disability) populations of 88 Illinois Public Use Micro Areas (PUMAs), areas with a mean of about 90,000 age 18–64 residents. Over 12 million ED visits to 201 non-federal Illinois hospitals were used to calculate visit rates by residents of each PUMA, using population-based mapping weights to allocate visits from zip codes to PUMAs. We then estimated n=88 correlations between population insurance-status changes and changes in ED visit rates per 1,000 residents comparing the two years before and after ACA implementation.ResultsThe baseline PUMA uninsurance rate ranged from 6.7% to 41.1% and there was 4.6-fold variation in baseline PUMA ED visit rates. The top quartile of PUMAs had >21,000 reductions in uninsured residents; 16 PUMAs had at least a 15,000 person increase in Medicaid enrollment. Compared to 2012–2013, 2014–2015 average monthly ED visits by the uninsured dropped 42%, but increased 42% for Medicaid and 10% for the privately insured. Areas with the largest increases in Medicaid enrollment experienced the largest growth in ED use; change in Medicaid enrollment was the only significant correlate of area change in total ED visits and explained a third of variation across the 88 PUMAs.ConclusionACA implementation in Illinois accelerated existing trends towards greater use of hospital ED care. It remains to be seen whether providing better access to primary and preventive care to the formerly uninsured will reduce ED use over time, or whether ACA insurance expansion is a part of continued, long-term growth. Monitoring ED use at the local level is critical to the success of new home- and community-based care coordination initiatives.

Access to Primary Care Appointments Following 2014 Insurance Expansions.

The Patient Protection and Affordable Care Act (ACA) expanded coverage to roughly 12 million individuals by mid-2014 and 20 million by 2016, raising concern about the capacity of the primary care system to absorb these individuals. We set out to determine how justified the concern was. We used an audit design in which simulated patients called primary care practices seeking new-patient appointments in 10 diverse states (Arkansas, Georgia, Iowa, Illinois, Massachusetts, Montana, New Jersey, Oregon, Pennsylvania, and Texas) from November 2012 through March 2013 and from May 2014 through July 2014, before and after the major ACA insurance expansions. Callers were randomly assigned to scripts specifying either private or Medicaid insurance and called only offices identified as "in network" for each plan. We completed 5,385 private insurance and 4,352 Medicaid calls in 2012-2013 and 2,424 private insurance and 2,474 Medicaid calls in 2014. Overall appointment rates for private insurance remained stable from 2012 (84.7%) to 2014 (85.8%) with Massachusetts and Pennsylvania experiencing significant increases. Overall, Medicaid appointment rates increased 9.7 percentage points (57.9% to 67.6%) with substantial variation by state. Across all callers, median wait times for those obtaining an appointment were 7 days in 2012 and 5 days in 2014, but the difference was not statistically significant. Contrary to widespread concern, we find no evidence that the millions of individuals newly insured through the ACA decreased new-patient appointment availability across 10 states as shown by stable wait times and appointment rates for private insurance as of mid-2014.

Emergency Department Visits and Hospitalizations for the Uninsured in Illinois Before and After Affordable Care Act Insurance Expansion.

We describe changes in emergency department (ED) visits and the proportion of patients with hospitalizations through the ED classified as Ambulatory Care Sensitive Hospitalization (ACSH) for the uninsured before (2011-2013) and after (2014-2015) Affordable Care Act (ACA) health insurance expansion in Illinois. Hospital administrative data from 201 non-federal Illinois hospitals for patients age 18-64 were used to analyze ED visits and hospitalizations through the ED. ACSH was defined using Agency for Healthcare Research and Quality (AHRQ) Prevention Quality Indicators (PQIs). Logistic regression was used to test the effect of time period on the odds of an ACSH for uninsured Illinois residents, controlling for patient sociodemographic characteristics, weekend visits and state region. Total ED visits increased 5.6% in Illinois after ACA implementation, with virtually no change in hospital admissions. Uninsured ED visits declined from 22.9% of all visits pre-ACA to 12.5% in 2014-2015, reflecting a 43% decline in average monthly ED visits and 54% in ED hospitalizations. The proportion of uninsured ED hospitalizations classified as ACSH increased from 15.4 to 15.5%, a non-significant difference. Older uninsured female, minority and downstate Illinois patients remained significantly more likely to experience ACSH throughout the study period. ED visits for the uninsured declined dramatically after ACA implementation in Illinois but over 12% of ED visits are for the remaining uninsured. The proportion of visits resulting in ACSH remained stable. Providing universal insurance with care coordination focused on improved access to home and ambulatory care could be highly cost effective.

Insurance status is associated with complex presentation among emergency general surgery patients

The Affordable Care Act has the potential to significantly affect access to care for previously uninsured patients in need of emergency general surgical care. Our objective was to determine the relationship between insurance status and disease complexity at presentation among a national sample of emergency general surgical patients. Data from the National Emergency Department Sample from 2006-2009 were queried to identify all patients aged 18-64years old admitted through the emergency department with a primary diagnosis of appendicitis, diverticulitis, inguinal hernia, or bowel obstruction. Primary outcome of complex presentation was defined as also presenting with generalized peritonitis, intra-abdominal abscess, perforated bowel, intestinal gangrene, or other disease-specific measures of complexity. We used multivariable logistic regression to determine the independent association between insurance status and complex presentation. Models accounted for patient- and hospital-level covariates. Counterfactual models were used to estimate the risk of complex presentation attributable to lack of insurance. A total of 1,373,659 patients were included, with an overall uninsured rate of 12.3%. Uninsured patients had significantly higher, unadjusted rates of complex presentation, and uninsured payer status was independently associated with complex presentation (odds ratio 1.38, 95% confidence interval: 1.34-1.42). Counterfactual models suggest that having insurance would result in a 22.37% (95% confidence interval: 22.35-22.39%) relative decline in risk of complex emergency general surgical presentation among the uninsured population. Insurance status is independently associated with severity of disease at presentation among emergency general surgical conditions nationally. In light of recently reaffirmed Affordable Care Act insurance expansion provisions, these results anticipate increased timely access to operative care for newly insured patients and a corresponding decline in complex, emergency general surgical presentations.

Most Uninsured Adults Could Schedule Primary Care Appointments Before The ACA, But Average Price Was $160.

Provisions of the Affordable Care Act (ACA) allow millions more Americans to obtain health insurance. However, a sizable number of people remain uninsured because they live in states that have not expanded Medicaid coverage or because they feel that Marketplace coverage is not affordable. Using data from a ten-state telephone survey in which callers posed as patients, we examined prices for primary care visits offered by physician offices to new uninsured patients in 2012-13, prior to ACA insurance expansions. Patients were quoted a mean price of $160. Significantly lower prices for the uninsured were offered by family practice offices compared to general internists, in offices participating in Medicaid managed care plans, and in federally qualified health centers. Prices were also lower for offices in ZIP codes with higher poverty rates. Only 18percent of uninsured callers were told that they could bring less than the full amount to the visit and arrange to pay the rest later. ACA insurance expansions could greatly decrease out-of-pocket spending for low-income adults seeking primary care. However, benefits of health reform are likely to be greater in states expanding Medicaid eligibility.

The Association of Generation Status and Health Insurance Among US Children

The Patient Protection and Affordable Care Act (ACA) has the potential to reduce the number of uninsured children in the United States by as much as 40%. The extent to which immigrant families are aware of and interested in obtaining insurance for their children is unclear. Data from the 2011-2012 National Survey of Children's Health were analyzed to examine differences by immigrant generational status in awareness of children's health insurance options. Adjusted odds ratios (AORs) were calculated for each outcome variable that showed statistical significance by generation status. Barriers to obtaining insurance for children in immigrant (first- and second-generation) families include awareness of and experience with various health insurance options, perceived costs and benefits of insurance, structural/policy restrictions on eligibility, and lower likelihood of working in large organizations that offer employee insurance coverage. Although noncitizen immigrants are not covered by ACA insurance expansions, only 38% of first-generation families report being uninsured because of the inability to meet citizenship requirements. Most families in this sample also worked for employers with <50 employees, making them less likely to benefit from expansions in employer-based insurance. In multivariate analyses, third-generation families have increased odds of knowing how to enroll in health insurance (AOR 7.1 [3.6-13.0]) and knowing where to find insurance information (AOR 7.7 [3.8-15.4]) compared with first-generation families. ACA navigators and health services professionals should be aware of potential unique challenges to helping immigrant families negotiate Medicaid expansions and state and federal exchanges.

Disproportionate-share hospital payment reductions may threaten the financial stability of safety-net hospitals.

Safety-net hospitals rely on disproportionate-share hospital (DSH) payments to help cover uncompensated care costs and underpayments by Medicaid (known as Medicaid shortfalls). The Affordable Care Act (ACA) anticipates that insurance expansion will increase safety-net hospitals' revenues and will reduce DSH payments accordingly. We examined the impact of the ACA's Medicaid DSH reductions on California public hospitals' financial stability by estimating how total DSH costs (uncompensated care costs and Medicaid shortfalls) will change as a result of insurance expansion and the offsetting DSH reductions. Decreases in uncompensated care costs resulting from the ACA insurance expansion may not match the act's DSH reductions because of the high number of people who will remain uninsured, low Medicaid reimbursement rates, and medical cost inflation. Taking these three factors into account, we estimate that California public hospitals' total DSH costs will increase from $2.044 billion in 2010 to $2.363-$2.503 billion in 2019, with unmet DSH costs of $1.381-$1.537 billion.