<human>:  When did the Affordable Care Act take effect?
<bot>: The Affordable Care Act was signed into law by President Obama on March 23, 2010. The ACA, commonly referred to as Obamacare, is a set of federal health care reforms that are intended to expand coverage to uninsured Americans, improve access to health care services, and slow the growth of health care costs. The ACA was enacted to address the rising cost of health care, which was threatening the stability of the entire US economy.