Workers with unstable hours, incomes, or employment were far less likely to have access to employer-sponsored health insurance, a new study found.
An estimated 14.6 million low- and middle-income U.S. workers had volatile incomes, while 11.4 million experienced substantial swings in weekly hours.
Researchers warn that Medicaid work requirements and Affordable Care Act changes taking effect in 2027 could disproportionately affect workers in volatile jobs.
With the growth of the gig economy, millions of working Americans with unpredictable schedules and fluctuating incomes rely on public health insurance because they lack consistent access to coverage through an employer, according to a new study.
The findings suggest that workers in unstable jobs could be especially vulnerable to forthcoming changes to Medicaid and Affordable Care Act (ACA) coverage, even when they work an average of more than 30 hours a week.
Researchers from Mount Sinai Hospital and the University of Michigan Medical School examined nationally representative data collected by the federal Medical Expenditure Panel Survey during 2022 and 2023. Their study, published inJAMA Network Open, included 1,621 low- and middle-income workers.
Workers whose weekly hours, annual incomes, or employment status changed substantially had much lower odds of being offered employer-sponsored health insurance, the researchers found. Compared with workers in more stable jobs, they were more likely to obtain coverage through Medicaid or an ACA marketplace plan.
Fewer traditional jobs
The findings reflect a labor market in which growing numbers of people work as contractors, freelancers, temporary employees, or gig workers. Others are self-employed, run small businesses, or combine several part-time jobs — arrangements that may not include health benefits.
“Low- and middle-income workers rely on those other forms of coverage because they can’t rely on access to employer coverage,” said senior author Dr. Sumit Agarwal, an assistant professor at the University of Michigan Medical School and School of Public Health.
Volatile incomes
The researchers classified income as volatile when it changed by more than 25% between 2022 and 2023. They also examined weekly fluctuations in working hours and transitions between unemployment and employment.
When the results were extrapolated to the U.S. population, the researchers estimated that 14.6 million low- and middle-income workers had volatile incomes, compared with 10.6 million whose incomes remained stable. About 11.4 million experienced volatile working hours, while 13.5 million had stable hours. An estimated 2.9 million experienced an employment disruption.
Despite the instability, workers across the groups averaged about 33 to 35 hours of work a week. Among those with volatile schedules, however, 70% worked fewer than 20 hours during at least some weeks of the year.
That variation could become particularly important in 2027, when 44 states are expected to begin requiring many adult Medicaid recipients to document at least 80 hours a month of work or other qualifying activities. Workers whose schedules occasionally fall below the threshold — or who struggle to document irregular work — could risk losing coverage.
Implementation will vary by state, including how work is reported, which activities qualify, and what exemptions are available. But Agarwal said the study indicates that workers already lacking employer-based benefits may face the greatest difficulties.
“These are people who are working,” he said, noting that some of his patients covered by Michigan’s Medicaid expansion program are already worried that their irregular schedules will make it difficult to satisfy the new requirements.
Affordable Care Act changes
ACA marketplace coverage is also set to change. The researchers noted that eligibility rules and costs will shift after enhanced premium subsidies for 2026 plans expire. Enrollment for 2027 marketplace plans is scheduled to begin Nov. 1.
The study focused on workers with incomes within the ranges relevant to Medicaid expansion and ACA financial assistance. During the period studied, an income equal to 400% of the federal poverty level was approximately $58,300 for an individual and $120,000 for a family of four.
Because the study was observational, it identifies associations between unstable employment and insurance coverage rather than proving that job volatility directly causes coverage gaps. However, repeated interviews conducted through the federal survey enabled researchers to distinguish workers with persistent instability from those with relatively stable work arrangements.