Beyond that, drug company-discounts on brand-name drugs and federal subsidies and discounts for all drugs would gradually reduce the gap, eliminating it by 2020. That means that seniors, who now pay 100 percent of their drug costs once they hit the doughnut hole, would pay 25 percent.

And, as under current law, once seniors spend a certain amount on medications, they would get "catastrophic" coverage and pay only 5 percent of the cost of their medications.

Meanwhile, government payments to Medicare Advantage, the private-plan part of Medicare, would be cut sharply starting in 2011. If you're one of the 10 million enrollees, you could lose extra benefits that many of the plans offer, such as free eyeglasses, hearing aids and gym memberships. To cushion the blow to beneficiaries, the cuts to health plans in high-cost areas of the country such as New York City and South Florida – where seniors have enjoyed the richest benefits -- would be phased in over as many as seven years.

Beginning this year, the bill would make all Medicare preventive services, such as screenings for colon, prostate and breast cancer, free to beneficiaries.

Q: How much is all this going to cost? Will it increase my taxes?

A: The bill is estimated to cost $940 billion over a decade. But because of higher taxes and fees and billions of dollars in Medicare payment cuts to providers, the bill would narrow the federal budget deficit by $138 billion over 10 years, according to the Congressional Budget Office.

If you have a high income, you face higher taxes. Starting in 2013, individuals would pay a higher Medicare payroll tax of 2.35 percent on earnings of more than $200,000 a year and couples earning more than $250,000, up from the current 1.45 percent. In addition, you'd face an additional 3.8 percent tax on unearned income such as dividends and interest over the threshold.

Starting in 2018, the bill would also impose a 40 percent excise tax on the portion of most employer-sponsored health coverage (excluding dental and vision) that exceeds $10,200 a year for individuals and $27,500 for families.

The bill also would raise the threshold for deducting unreimbursed medical expenses from 7.5 percent of adjusted gross income to 10 percent.

The bill also would limit the amount of money you can put in a flexible spending account to pay medical expenses to $2,500 starting in 2013. Those using an indoor tanning salon will pay a 10 percent tax starting this year.

Q: What will happen to my premiums?

A: That's hard to predict and the subject of much debate. People who are sick might face lower premiums than otherwise because insurers wouldn't be permitted to charge sick people more; healthier people might pay more. Older people could still be charged more than younger people, but the gap couldn't be as large.