This document provides a timeline and overview of key provisions in the Patient Protection and Affordable Care Act (ACA). It outlines the legislative timeline from when the House and Senate passed versions of health care reform in 2009-2010 to when President Obama signed the bill into law. It then summarizes major ACA provisions being implemented from 2010 through 2018 and beyond, including requirements for insurance plans, the establishment of health insurance exchanges, Medicaid expansion, and individual/employer mandates. The document concludes by discussing how the ACA is paid for through various new taxes and fees and its projected impact on the private health insurance marketplace.