The Affordable Care Act (ACA) is a comprehensive healthcare reform act signed into law in March 2010, during Barack Obama’s first presidency.
The legislation aimed to “make affordable health insurance available to more people” by offering tax credits to some enrollees, expanding Medicaid to be available based on income alone, and supporting innovation to lower the cost of providing healthcare.
Is Obamacare the same thing as the ACA?
Yes — “Obamacare” is an unofficial nickname for the ACA, used both inside and outside of government.
What did the ACA do?
The ACA had implications across the healthcare and insurance industries, including introducing a number of changes to how people get insured.
In 2013, 85.5% of Americans were covered by public or private health insurance, leaving 14.5% uninsured. The ACA went into effect in 2014. By 2016, 91.4% were insured, dropping the uninsured percentage to 8.6%, a 5.9-point shift.
In early 2023, the Department of Health and Human Services reported that more than 40 million people had enrolled in ACA-related insurance plans.
Since the passage of the ACA, increases in public coverage have accounted for most of the change in the uninsured rate — from 2010 to 2023, public insurance coverage grew 7.7 percentage points from 29.7% of the population to 37.4% while private coverage grew 1.2 percentage points from 65.8% to 67.0%.
Individual mandate
One of the ACA’s changes introduced the requirement that most American citizens either have health insurance or pay a penalty tax, a provision known as the individual mandate.
The mandate faced numerous legal challenges arguing the constitutionality of requiring Americans to maintain healthcare coverage. It was upheld by the Supreme Court in 2012 before being reversed in the 2017 Tax Cuts and Jobs Act, which removed the penalty in 2019 tax returns.
Employer mandate
Most companies with 50 or more full-time (or full-time equivalent) employees are subject to the “employer shared responsibility provisions.” They’re required to either provide employees with basic affordable health insurance or pay a tax of their own. The ACA also requires employers to offer employees information about their coverage options.
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Expansion of Medicaid
The ACA also expanded Medicaid, the nation’s public health care option for low-income adults, the elderly, and people with disabilities.
When the bill was challenged in 2012, the Supreme Court essentially made Medicaid expansion optional for states. In states that did expand the program, everyone in households with incomes below 138% of the federal poverty level became eligible. Under the ACA, 40 states and Washington, DC, have expanded Medicaid while the remaining 10 have not.
The Medicaid expansions went into effect in 2014, increasing the number of people who qualified for government health insurance. Between January 2014 and 2015, Medicaid enrollment increased from 63.9 million to 75.4 million people, an 18% increase.
After that influx, enrollment remained relatively flat until the COVID-19 pandemic, when Congress required states to automatically renew peoples’ Medicaid coverage regardless of circumstances or changing eligibility. Medicaid enrollment then grew from 74 million people in March 2020 to a peak of over 100 million in April 2023.
The policy of continuous enrollment ended in spring 2023, leading to a drop in Medicaid enrollees.
Preexisting conditions
The ACA made it unlawful for health insurance providers to deny coverage based on a “preexisting condition” — that is, a health issue for which a person had symptoms or a diagnosis at the time the insurance coverage started.
At around the same time, the Centers for Medicare and Medicaid Services estimated that between 19% and 50% of Americans under the age of 65 had a preexisting condition.
Dependents
ACA changes also established that dependents could stay on a parent’s insurance plan until their 26th birthday, at which point they’d need to find their own coverage. According to the Centers for Disease Control and Prevention, the percentage of 19- to 25-year-olds without health insurance fell from 32.8% in 2009 to a low of 13.9% in 2014.
This provided additional care for the least-insured age group. It also kept relatively healthier people paying into insurance markets. Heathier people tend to have lower healthcare expenses, so more young people participating in insurance markets subsidizes the cost of caring for older participants and lowers premiums.
Cancellations, appeals, and limits
The ACA also included more protections for the insured, prohibiting providers from canceling coverage based on a mistake on an application. It guaranteed people the opportunity to appeal any decisions on insurance claims and eliminated annual and lifetime limits on what plans pay for essential healthcare. In 2012, the Department of Health and Human Services estimated that this impacted 105 million policies.
Preventative care
For the first time, the ACA required most insurance plans to cover basic preventative care, including:
- blood pressure, diabetes, and cholesterol tests
- cancer screenings
- medical counseling
- well-baby and well-child visits
- flu shots and other vaccines
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Page sources and methodology
All of the data on the page was sourced directly from government agencies. The analysis and final review was performed by USAFacts.
Census Bureau
Health Insurance Coverage in the United States
Centers for Disease Control and Prevention
Health, United States
