How Unstable Work Hours Affect Health Insurance Access for Low- and Middle-Income Workers

The findings indicate that workers experiencing unstable weekly hours or fluctuating annual incomes are significantly less likely to have access to employer-sponsored health insurance. According to the research team, these individuals tend to be younger, predominantly female, and earn lower wages compared to workers with stable schedules in similar income brackets.

How Variable Work Hours Drive Insurance Shifts

Millions of American jobs now rely on gig work, contracting, freelancing, temporary assignments, or multiple part-time positions. According to the Mount Sinai and University of Michigan researchers, workers in these arrangements often experience extreme volatility in their weekly hours. Specifically, 70% of workers with volatile hours reported schedules that dipped below 20 hours per week at various points during the year, even though their average weekly hours ranged from 33 to 35 hours.

Because companies frequently structure these roles to exclude benefits, affected workers cannot depend on employer-sponsored coverage. Instead, they rely heavily on Medicaid and health plans purchased through the ACA Marketplaces. Sumit Agarwal, M.D., M.P.H., Ph.D., an assistant professor at the U-M Medical School and School of Public Health and senior author of the study, noted that these populations rely on public safety-net programs because traditional employer-first insurance options leave them behind. “They are the ones who will be hurt the most from changes in health policy that reduce access to the programs, such as Medicaid expansion and the ACA Marketplace, that were intended to fill in the gaps in the employer-first insurance system,” Agarwal said.

Policy Changes Looming for 2027 Coverage

The study’s publication coincides with major regulatory shifts scheduled for 2027 that threaten to disrupt coverage for vulnerable workers. Starting in 2027, 44 states will require millions of Medicaid enrollees to document that they work at least 80 hours per month—averaging about 20 hours a week—or meet alternative criteria to maintain their benefits. Enrollees who fail to meet these documentation thresholds face disenrollment.

Researchers warn that workers with volatile schedules will prove especially vulnerable to losing Medicaid coverage. Even though these individuals often work substantial cumulative hours over a year, their fluctuating weekly hours frequently dip below the mandatory monthly thresholds during slow periods. At the same time, the ACA Marketplace faces new cost increases and eligibility adjustments tied to immigration status for 2027 coverage, following the expiration of enhanced premium subsidies for 2026 plans.

Income Thresholds and Safety-Net Reliance

The study focused on individuals with household incomes up to limits qualifying them for Medicaid or ACA subsidies. In states that expanded Medicaid under the ACA, adults under 65 with incomes up to 138% of the federal poverty level qualify for coverage. For 2026, this 138% threshold amounts to just over $22,000 for a single person and $45,500 for a family of four. For ACA Marketplace subsidies, the study examined individuals with incomes up to 400% of the poverty level, which stood at approximately $58,300 for a single person and $120,000 for a family of four during the 2022–2023 study period, scaling up to $63,840 and $132,000 respectively by 2026.

Workers navigating these income bands who lack predictable schedules find themselves caught between eligibility cliffs and changing state documentation mandates. As enrollment for 2027 ACA Marketplace plans opens on November 1 via HealthCare.gov, policy experts emphasize that fluctuating employment models will continue to challenge the stability of health coverage for millions of working Americans.