Federal health care reform affects everyone from infants to the elderly.

If you're 65 or older and rely on Medicare for health insurance, here are four of the most significant changes under the Patient Protection and Affordable Care Act:

1. Free preventive care

Under the law, you qualify for a free annual wellness exam and other preventive care services if you have Medicare Part B coverage, which pays for doctors visits and other outpatient medical services. (Part A provides hospital coverage.) "Free" means you don't have to pay any out-of-pocket costs - such as a deductible, co-payment or co-insurance - for the exam. Other free preventive care services include:

  • Bone mass measurement
  • Mammograms and screenings for cholesterol, blood pressure, diabetes, prostate cancer and others
  • Counseling to quit smoking
  • Flu, pneumonia and hepatitis B shots

The preventive care provision has been in effect since Jan. 1, 2011. The law does not require Medicare Advantage plans to cover preventive care free, but many plans do anyway. Check with your plan if you have Medicare Advantage to see whether it covers preventive services without charging you a deductible or co-payment.

2. A smaller 'donut hole'

The "donut hole" refers to the coverage gap that occurs each year when you have a Medicare Part D drug plan and reach the plan's annual coverage limit. At that point, you have to pay for prescriptions out of pocket.

Under reform, people who reach the gap get a 50 percent discount on brand-name drugs covered by Medicare and a 14 percent discount on generic drugs.

The discount will gradually increase until the coverage gap is eliminated in 2020. You are eligible for the discount if you are enrolled in a Medicare Part D drug plan or a Medicare Advantage plan that includes drug coverage.

3. More coordination of care

Hospitals, doctors and other providers can form groups called accountable care organizations (ACOs) to improve coordination of your care. Ideally, that will mean your doctors will all be on the same page when it comes to planning your care. Medicare will reward ACOs that improve quality of care and cost efficiency.

4. Emphasis on improving hospital care

Hospitals that provide high-quality care will get incentives from Medicare starting in October 2012 through a new program called the Hospital Value-Based Purchasing Program. The new program will pay hospitals based on the quality of care they offer, not just quantity of the services they provide.

To learn more about medical insurance through Medicare, visit the federal government's health care reform website.