The Affordable Care Act (ACA), , codified as amended at scattered sections of the Internal Revenue Code and in 42 U.S.C. is divided into 10 titlesPatient Protection and Affordable Care Act from Wikisource. and contains provisions that became effective immediately, 90 days after enactment, and six months after enactment, as well as provisions phased in through to 2020. Below are some of the key provisions of the ACA. For simplicity, the amendments in the Health Care and Education Reconciliation Act of 2010 are integrated into this timeline.

Provisions by effective date

Effective at enactment, March 23, 2010 The Food and Drug Administration is now authorized to approve generic versions of biologic drugs and grant biologics manufacturers 12 years of exclusive use before generics can be developed. The Medicaid drug rebate for brand name drugs, paid by drug manufacturers to the states, is increased to 23.1% (except for the rebate for clotting factors and drugs approved exclusively for pediatric use, which increases to 17.1%), and the rebate is extended to Medicaid managed care plans; the Medicaid rebate for non-innovator, multiple source drugs is increased to 13% of average manufacturer price. A non-profit Patient-Centered Outcomes Research Institute is established, independent from government, to undertake comparative effectiveness research. This is charged with examining the "relative health outcomes, clinical effectiveness, and appropriateness" of different medical treatments by evaluating existing studies and conducting its own. Its 19-member board is to include patients, doctors, hospitals, drug makers, device manufacturers, insurers, payers, government officials and health experts. It will not have the power to mandate or even endorse coverage rules or reimbursement for any particular treatment. Medicare may take the institute's research into account when deciding what procedures it will cover, so long as the new research is not the sole justification and the agency allows for public input. The bill prohibits the institute from developing or employing "a dollars per quality adjusted life year" (or any similar measure that discounts the value of a life because of an individual's disability) as a threshold to establish what type of health care is cost effective or recommended. This makes it different from the UK's National Institute for Health and Clinical Excellence, which determines cost-effectiveness directly based on quality-adjusted life year valuations. The Prevention and Public Health Fund was created to fund programs and research designed to increase chronic disease prevention. A National Prevention, Health Promotion and Public Health Council (National Prevention Council) was created to develop a national strategy on prevention, health promotion and public health; by, for example, disseminating evidenced-based recommendations on the use of clinical and community prevention services. The Indian Health Care Improvement Act was reauthorized and amended. Chain restaurants and food vendors with 20 or more locations are required to display the caloric content of their foods on menus, drive-through menus, and vending machines. Additional information, such as saturated fat, carbohydrate, and sodium content, must also be made available upon request. But first, the Food and Drug Administration has to come up with regulations.Alexandra Giaimo, FDA Misses Deadline for Menu-Labeling Regulations (March 31, 2011). Two regulations – one applicable to restaurants and another to vending machines – have been proposed, but have not yet been made final.Overview of FDA Proposed Labeling Requirements for Restaurants, Similar Retail Food Establishments and Vending Machines , Food and Drug Administration. States can apply for a "State Plan Amendment" to expand family planning eligibility to the same eligibility as pregnancy related care through a state option rather than having to apply for a federal waiver.

Effective June 21, 2010 Adults with existing conditions became eligible to join a temporary high-risk pool, which will be superseded by the health care exchange in 2014. To qualify for coverage, applicants must have a pre-existing health condition and have been uninsured for at least the past six months. There is no age requirement. The new program sets premiums as if for a standard population and not for a population with a higher health risk. Allows premiums to vary by age (up to 3:1), geographic area, family composition and tobacco use (up to 1.5:1). Limit out-of-pocket spending to $5,950 for individuals and $11,900 for families, excluding premiums.

Effective July 1, 2010 The President established, within the Department of Health and Human Services (HHS), a council called the National Prevention, Health Promotion and Public Health Council to help begin to develop a National Prevention and Health Promotion Strategy. The Surgeon General shall serve as the chairperson of the new Council.Wikisource:Patient Protection and Affordable Care Act/Title IV#Subtitle AExecutive Order 13544 – Establishing the National Prevention, Health Promotion, and Public Health Council, June 10, 2010, Vol. 75, No. 114,  A 10% sales tax on indoor tanning took effect.

Effective July 19, 2010 The Departments of Health and Human Services, Labor, and Treasury published interim final regulations requiring new plans and issuers to cover certain preventive services without any cost-sharing for the enrollee when delivered by in-network providers.

Effective September 23, 2010 Insurers are prohibited from imposing lifetime dollar limits on essential benefits, like hospital stays, in new policies issued. Dependents, mostly children, will be permitted to remain on their parents' insurance plan until their 26th birthday,H.R. 3590 Enrolled , section 1001 (adding section 2714 to the Public Health Service Act): "A group health plan and a health insurance issuer offering group or individual health insurance coverage that provides dependent coverage of children shall continue to make such coverage available for an adult child (who is not married) until the child turns 26 years of age." and regulations implemented under the ACA include dependents that no longer live with their parents, are not a dependent on a parent's tax return, are no longer a student, or are married. Insurers are prohibited from excluding pre-existing medical conditions (except in grandfathered individual health insurance plans) for children under the age of 19.Language in the law concerning this provision has been described as ambiguous, but representatives of the insurance industry have indicated they will comply with regulations issued by the Secretary of Health and Human Services reflecting this interpretation.

All new insurance plans must cover preventive care and medical screenings rated Level A or B by the U.S. Preventive Services Task Force. Insurers are prohibited from charging co-payments, co-insurance, or deductibles for these services. Individuals affected by the Medicare Part D coverage gap will receive a $250 rebate, and 50% of the gap will be eliminated in 2011. The gap will be eliminated by 2020. Insurers' abilities to enforce annual spending caps will be restricted, and completely prohibited by 2014. Insurers are prohibited from dropping policyholders when they get sick. Insurers are required to reveal details about administrative and executive expenditures. Insurers are required to implement an appeals process for coverage determination and claims on all new plans. Enhanced methods of fraud detection are implemented. Medicare is expanded to small, rural hospitals and facilities. Medicare patients with chronic illnesses must be monitored/evaluated on a 3-month basis for coverage of the medications for treatment of such illnesses. Companies that provide early retiree benefits for individuals aged 55–64 are eligible to participate in a temporary program that reduces premium costs. A new website installed by the Secretary of Health and Human Services will provide consumer insurance information for individuals and small businesses in all states. A temporary credit program is established to encourage private investment in new therapies for disease treatment and prevention. All new insurance plans must cover childhood immunizations and adult vaccinations recommended by the Advisory Committee on Immunization Practices (ACIP) without charging co-payments, co-insurance, or deductibles when provided by an in-network provider.

Effective January 1, 2011 Insurers must spend 80% (for individual or small group insurers) or 85% (for large group insurers) of premium dollars on health costs and claims, leaving only 20% or 15% respectively for administrative costs and profits, subject to various waivers and exemptions. If an insurer fails to meet this requirement, there is no penalty, but a rebate must be issued to the policy holder. This policy is known as the 'Medical Loss Ratio'. The Centers for Medicare and Medicaid Services is responsible for developing the Center for Medicare and Medicaid Innovation and overseeing the testing of innovative payment and delivery models. Flexible spending accounts, health reimbursement accounts, and health savings accounts cannot be used to pay for over-the-counter drugs, purchased without a prescription, except insulin.

Effective September 1, 2011

All health insurance companies must inform the public when they want to increase health insurance rates for individual or small group policies by an average of 10% or more. This policy is known as 'Rate Review'. States are provided with Health Insurance Rate Review Grants to enhance their rate review programs and bring greater transparency to the process.

Effective January 1, 2012 Employers must disclose the value of the benefits they provided beginning in 2012 for each employee's health insurance coverage on the employee's annual Form W-2's. This requirement was originally to be effective January 1, 2011, but was postponed by IRS Notice 2010–69 on October 23, 2010. Reporting is not required for any employer that was required to file fewer than 250 Forms W-2 in the preceding calendar year. New tax reporting changes were to come in effect. Lawmakers originally felt these changes would help prevent tax evasion by corporations. However, in April 2011, Congress passed and President Obama signed the Comprehensive 1099 Taxpayer Protection and Repayment of Exchange Subsidy Overpayments Act of 2011 repealing this provision, because it was burdensome to small businesses. Before the ACA, businesses were required to notify the IRS on form 1099 of certain payments to individuals for certain services or property over a reporting threshold of $600. Under the repealed law, reporting of payments to corporations would also be required. Originally it was expected to raise $17 billion over 10 years. The amendments made by Section 9006 of the ACA were designed to apply to payments made by businesses after December 31, 2011, but will no longer apply because of the repeal of the section.

Effective August 1, 2012 All new plans must cover certain preventive services such as mammograms and colonoscopies without charging a deductible, co-pay or coinsurance. Women's Preventive Services – including: well-woman visits; gestational diabetes screening; human papillomavirus (HPV) DNA testing for women age 30 and older; sexually transmitted infection counseling; human immunodeficiency virus (HIV) screening and counseling; FDA-approved contraceptive methods and contraceptive counseling; breastfeeding support, supplies and counseling; and domestic violence screening and counseling – will be covered without cost sharing. The requirement to cover FDA-approved contraceptive methods is also known as the contraceptive mandate.

Effective October 1, 2012