The Affordable Care Act (ACA), also known as Obamacare, is a comprehensive healthcare reform law enacted in the United States in March 2010. It aimed to increase the quality and affordability of health insurance, lower the uninsured rate by expanding public and private insurance coverage, and reduce the overall costs of healthcare.

Key provisions of the ACA include:

1. Individual Mandate: Individuals are required to have health insurance coverage or pay a penalty, although this provision was effectively nullified in 2017 with the passing of the Tax Cuts and Jobs Act, which reduced the penalty to $0.

2. Marketplace Exchanges: The ACA established state-based health insurance marketplaces where individuals and small businesses can purchase health insurance plans. These exchanges offer subsidies to eligible individuals and families to help lower the cost of premiums.

3. Medicaid Expansion: The ACA expanded Medicaid eligibility to cover more lowincome adults, although the expansion was optional for states, resulting in a patchwork of coverage across the country.

4. Protections for Consumers: The ACA introduced several consumer protections, including prohibiting insurance companies from denying coverage to individuals with pre-existing conditions, allowing young adults to stay on their parents' insurance plans until age 26, and requiring coverage of essential health benefits.

The ACA is primarily designed to benefit uninsured and underinsured individuals and families, as well as those with pre-existing conditions who may have struggled to obtain affordable coverage before its enactment. It also aims to provide more comprehensive coverage and preventative care to all Americans.

As for how long it will last, it's difficult to predict definitively. The ACA has faced numerous legal and political challenges since its inception, including attempts by lawmakers to repeal or weaken it. However, as of my last update, it remains in effect, though certain provisions have been modified or repealed over time. Its longevity ultimately depends on the political landscape and any future legislative actions taken regarding healthcare policy in the United States.