Five ways the Affordable Care Act improved health care in the United States

The Affordable Care Act turns 16 this month. Before it passed, insurers could deny you coverage for a pre-existing condition, cut you off when your bills got too high, and charge you full price with no help. Here’s what changed.

Sixteen years ago, President Barack Obama signed the Affordable Care Act (ACA) into law. Since then, it has been praised, attacked, partially dismantled, and repeatedly declared dead, and yet, it’s still here. 

But lost in 16 years of political fighting over “Obamacare” is what did it actually do for people? To mark the anniversary, here are five things the ACA did for Americans.

1. Insurance companies can no longer use your health history against you

Before the ACA, if you had cancer, diabetes, or a history of depression, an insurer could legally deny you coverage, charge you dramatically higher premiums, or simply refuse to cover treatment related to your condition. 

It was legal. It was common. And it left millions of Americans without meaningful access to care.

The ACA made that illegal. Insurers can no longer deny you coverage or charge you more because of a pre-existing condition. Full stop. For the roughly 130 million Americans living with some form of pre-existing condition, that protection is the difference between having health care and not.

2. Insurance companies can no longer cut you off when your bills get too high

Before the ACA, insurance policies could set annual and lifetime caps on how much they would pay out. Get sick enough due to a cancer diagnosis, a serious accident, or a premature birth, and you could hit your limit and find yourself suddenly uninsured mid-treatment, on the hook for everything that followed.

The ACA banned both annual and lifetime caps on essential health benefits. Your insurer cannot cut you off when your bills become inconvenient.

3. Your kids can stay on your insurance until they’re 26.

For millions of young Americans, the years between leaving school and landing a job with decent benefits are a coverage gap. Entry-level jobs often don’t come with health insurance. Before the ACA, that gap could stretch for years with no good options.

The ACA required insurers to let adult children stay on their parents’ plan until age 26. It’s one of the law’s least controversial provisions and one of its most used—covering millions of young people at exactly the moment they’re most likely to be uninsured.

4. Financial help is available to people who buy their own insurance

Before the ACA, if you didn’t get insurance through an employer or a public program, you were largely on your own in the individual market—paying full price for coverage that could still be denied based on your health history.

The ACA created a sliding scale of tax credits based on income to help people afford coverage. At lower income levels, plans can cost as little as $0 per month. The law also created health insurance marketplaces where people can compare plans side by side. 

2026 is the first year since 2020 that individual signups for ACA marketplace coverage declined. This is likely due to the expiration of COVID-era subsidies that the Republican-led Congress did not extend past 2025. 

The loss of those subsidies made coverage unaffordable for millions of Americans, and those who were able to keep their plans are still seeing their premiums rise significantly. KFF estimates show enrollees who received subsidies are seeing their premiums increase by 114% increase on average, from $888 in 2025 to $1,904 in 2026.

5. Most preventive care is free

Before the ACA, seeing a doctor before something went wrong could cost you. Copays, deductibles, and out-of-pocket costs meant that many Americans skipped preventive care and caught conditions later, when they were harder and more expensive to treat.

The ACA required insurers to cover a broad range of preventive services at no cost to the patient. Vaccines, cancer screenings, mammograms, birth control with no copay or deductible. The idea was simple: it is cheaper and better to catch things early. 

It’s a provision that sounds unremarkable until you consider what it replaced.

Sixteen years in, the ACA remains politically divisive. But the changes it made to the day-to-day experience of having health insurance are largely invisible now, because they’ve become the baseline.