The Affordable Care Act requires health insurers to reduce the level of cost-sharing for silver plans sold in the insurance marketplaces to low-income people earning between 100 and 250 percent of poverty. This study looks at the financial impact of cost-sharing reductions on the people who qualify for them. To do this, we analyzed plans selected by hypothetical 40 year-old, nonsmoking adults with annual incomes that make them eligible for the reductions ($17,000, $20,000, or $25,000) compared to someone with an income of $35,000 who would not qualify for the reductions. In our study, each person purchases the second-lowest-cost silver plan available in the largest city in each of the 38 states that use the HealthCare.gov website to enroll residents in marketplace plans. This analysis finds that the cost sharing reductions substantially lower deductibles and out-of-pocket spending limits in marketplace plans, as well as the copayments required for primary care and specialist visits, generic and preferred brand-name drugs, and emergency room visits. For example, the median out-of-pocket limit in silver benchmark plans for adults with incomes above the level that makes them eligible for the reductions is $6,500. But the median out-of-pocket limit for someone earning $25,000 is $5,000, $1,850 for someone earning $20,000 and $650 for someone earning $17,000. While the cost-sharing reductions lower people's out-of-pocket costs, the degree to which they do so depends on the person's health care use and health plan. If the House of Representatives prevails in its suit against the Obama administration challenging the financing of these reductions, up to 7 million people will have higher out-of-pocket costs than before. This may lead many people, especially those in good health, to disenroll from their plans, an event that could destabilize the marketplaces.