You may have heard rumors lately that Medicare Part B premiums are shooting up – by as much as 200 percent.

Those rumors are completely false, I’m happy to say.

In fact, for most people with Medicare, the Part B premium will rise by $3.50 per month in 2012. That means the total monthly premium will be $99.90.

Medicare is divided into four parts, A, B, C, and D. Part A pays for hospital inpatient care, skilled nursing care, hospice, and some home health care.

Part B pays for doctor services, outpatient care, and some other types of home health.

Part C, also known as Medicare Advantage, finances managed care plans, like HMOs and PPOs, operated by private companies approved by Medicare. And Part D is the Medicare prescription drug program.

Only about 1percent of people with Medicare pay Part A premiums, since they paid enough in Medicare taxes over their working lives to qualify for premium-free Part A. We expect Part C premiums to be 4 percent lower, on average, next year. And Part D premiums will be about the same next year as this year.

People with Medicare pay 25 percent of their Part B premiums; the government picks up the rest. The actual amount of the premium is set each year based on expected care costs for all Medicare beneficiaries.

The “standard” Part B premium of $96.40 – the amount paid by most beneficiaries – had stayed the same since 2008, under a law that prohibits increases in Part B premiums in years in which there’s no cost-of-living increase in Social Security payments.

But retired workers will receive an average of $43 more each month in their Social Security checks next year. That will more than offset the $3.50 per month rise in standard Part B premiums.

The Part B deductible for 2012 will be $140, a decrease of $22 from this year.

The Part A deductible paid by beneficiaries when admitted as a hospital inpatient will be $1,156 in 2012, an increase of $24 from this year’s $1,132. This change is well below increases in previous years and general inflation.

I also want to remind everyone with Medicare that the end of open enrollment season is drawing near. The deadline for choosing a new Medicare health or prescription drug plan is Dec. 7.

People with Medicare should check their current plans to make sure they’re still a good fit. Can you still afford the premiums? Does your plan still cover the medical services and drugs you need?

If you’d like help sorting through all the choices, take a look at the “Medicare & You” handbook that was mailed to you recently. It lists all the health and drug plans that offer coverage in your area.

You also may want to check out Medicare’s online Plan Finder tool at www.Medicare.gov. Among other things, Plan Finder lets you enter the names of the medications you’re taking and find a plan that covers most or all of them.

Beginning this year, Plan Finder also rates Medicare Advantage plans according to our Five-Star Rating System. A gold icon indicates plans that received five stars, the highest rating for quality of care and customer service. We encourage people with Medicare to enroll in plans with higher ratings — and we hope lower-rated plans will work hard to improve their care and service.

I also wanted to let you know that, thanks to the Affordable Care Act, people who fall into the Part D “donut hole” will be eligible for 50 percent discounts on covered brand-name drugs next year. About 1.8 million Medicare beneficiaries have gotten cheaper drugs this year through the discount.

Also thanks to the Affordable Care Act, Medicare preventive health benefits are now available for free. These services include cancer screenings and an annual wellness visit with your doctor.

David Sayen is Medicare’s regional administrator for California, Arizona, Nevada, Hawaii, and the Pacific Trust Territories. You can always get answers to your Medicare questions by calling 1-800-MEDICARE (1-800-633-4227).