The number of people with health insurance are at their highest levels in nearly 20 years. In the first nine months of 2015, nearly 91% of people, from babies to 64-year-olds, had some form of health insurance. That’s 16 million more people than in 2013, before the Affordable Care Act went into effect.

The most dramatic increase in health care coverage was for children, according to the Center for Disease Control’s latest data. Among children under age 18 years, the total share of youth without insurance fell to 4.5%, down from 14% in 1997.

The federal report doesn’t analyze the reasons for the gains in health insurance. But it’s clear that the Affordable Care Act — often referred to as Obamacare — played a role. It has implications for the presidential race, too, as several Republican candidates have vowed to repeal Obamacare.

Some of the jump in coverage among children is due to Medicaid and the Children’s Health Insurance Program (CHIP); it provides coverage to more than one in three kids in the U.S. Those programs alone cut the rate of uninsured children in half between 1997 and 2012 when 7% of children were uninsured. Since then, health care coverage among children has continued to increase across both public and private plans. The percentage of children (under age 18) with private coverage increased to 55.1% in the first nine months of 2015 from 52.6% in 2013, prior to the ACA taking effect. Currently, about 2% of children–or 1.5 million in total–have exchange-based health care plans.

Part of the insurance expansion among kids is a credit to ACA subsidies, which help offset the cost of plans for those parents or guardians who make slightly too much to apply for CHIPs. An estimated half a million uninsured children qualified for the new subsidies as of 2013, according to a Kaiser Family Foundation analysis.

Another factor is that more parents have gained coverage. That’s a byproduct of Obamacare as well as an improving job market. Another Kaiser Family Foundation report breaks it down:

Research shows that expanding coverage for parents leads to significant increases in coverage for children and more stable coverage for children over time; studies also show that, when parents are covered, children are more likely to receive needed care.

Therefore, it isn’t surprising that the drastic decrease in uninsured adults to 10.6% in 2015 from 16.6% in 2013, resulted in even greater gains for children.