How does health spending among demographic groups compare to Affordable Care Act premium regulations?

The Affordable Care Act (ACA) substantially altered regulations in the nongroup and small group health insurance markets and those markets continue to receive significant policy attention. To understand how those markets have functioned in recent years and how they would be impacted by policy changes, we estimated enrollment and spending by age and sex using claims data covering enrollment in ACA risk‐adjusted plans in 2017–2019 and compared spending to a federal default age‐rating curve for premiums. Our results suggest that women aged 55–64 helped stabilize the nongroup market through high enrollment and relatively low spending. Men enrolled in the marketplace also subsidized other nongroup enrollees but to a lesser extent than expected. In fact, men aged25–50 enrolled in nongroup plans spent 18% more than their counterparts enrolled through a small employer. These unique spending patterns have interesting policy implications, including that lowering the Medicare eligibility age would likely increase premiums in the nongroup market.