Much of the health care law is in effect now. — Photo by Getty Images/Blend Images

The Affordable Care Act — also referred to as the health care law or "Obamacare" — was signed into law on March 23, 2010.

See also: 11 Myths About the Health Care Law

Last June, the U.S. Supreme Court upheld the law. And starting this October, people who have been denied coverage because of a pre-existing health condition, or haven't been to afford the high costs of individually purchased insurance, will be able to sign up for lower-priced group plans. These policies, and other protections in the law, will go into effect on January 1, 2014.

Here's your at-a-glance guide to the provisions and benefits available now, as well as some still to come.

Benefits in Effect Now

Expanded coverage for preventive care and screenings

People who have Medicare Part B as well as those covered by many individual and employer-sponsored health plans are eligible for free — i.e., no deductibles or copayments — preventive and wellness benefits, such as annual health exams, immunizations, mammograms and other screenings for diseases including diabetes and certain cancers. For instance, Medicare Part B enrollees can have a free wellness visit with their doctor every year. (See "What You Need to Know About the New, Free Medicare Checkup.") People with other types of insurance can ask their insurance company or physician about the free preventive services now available to them. 

New options for people with pre-existing conditions

Soon after passage of the law, adults whom private insurers considered to be "high-risk" and uninsurable due to prior or current health problems — and who had been uninsured for at least six months — were able to buy temporary insurance through the federal Pre-Existing Condition Insurance Plan (PCIP). More than 100,000 people enrolled in the program. Starting on January 1, 2014, all Americans will be eligible to purchase affordable insurance regardless of their health status or pre-existing medical conditions.

Lowered costs for people in the Medicare Part D "Doughnut Hole"

People with Medicare Part D who fall into the prescription drug coverage gap receive a 52.5 percent discount on most brand-name prescriptions and biologic drugs, as well as a discount on generic drugs. For 2013, the generic drug discount is 21 percent. (To learn more, see the Ms. Medicare columns "Paying Less for Drugs in the Doughnut Hole" and "Can a Drug Cost You Less in the Doughnut Hole?") Since the law's enactment, more than 6.1 million people with Medicare have saved $5.7 billion on prescription drugs. In 2012, Part D enrollees who reached the gap saved an average of $706 a year in their prescription costs.

Greater consumer protections against insurance cancellations

A common practice among insurers seeking to deny payments for costly medical care has been to re-examine customers' initial applications and cancel or "rescind" policies. Now, due to the health care law, as long as you pay your premiumns, your health insurance is guaranteed. The health care law prohibits insurers from rescinding coverage because of unintentional mistakes or minor omissions on an application.

An end to lifetime limits on health insurance coverage

Insurers can no longer limit how much they will pay out in essential medical services over a person's lifetime. This benefit is now automatically in effect on all insurance policies.

Higher annual limits on health insurance coverage

Most insurance plans must now cover medical expenses up to at least $1.25 million per year. (See page 3 for more about annual coverage limits).

Expanded coverage for adult children up to age 26

Young adults who don't have access to an employer health plan can now stay on a parent's health insurance policy until they turn 26, even if they are married or don't live at home. Previously, most insurance plans kicked young adults off family policies when they turned 18 or, if the young adult was in college, soon after graduation.

Next page: More benefits, including help for early retirees. >>