Multiple pricing tiers. Costly drugs. Bigger bills. Complicated forms. The federal government's annual Medicare open enrollment period can seem overwhelming for the more than 50 million beneficiaries obtaining coverage through the program. One wrong step can result in higher health care costs, but it isn't always easy to know what to do.

"We did focus groups asking seniors how they choose and change their health insurance plans, and overall, seniors found it to be a very confusing process and an overwhelming process," Gretchen Jacobson, associate director of Medicare policy at the Kaiser Family Foundation health policy research organization, told CNBC. "Seniors said they don't like to revisit their plan choices and go through that process again, because they found it frustrating to begin with."

Here's four things you need to know about the Medicare open enrollment to protect your coverage:

What are the Medicare open enrollment dates for 2014? The enrollment period began Oct. 15. People already enrolled will be able to change insurers and sign up for different coverage plans through Dec. 7. There's no need to rush and make a decision right away. Experts recommend carefully taking the time to read through the coverage plans and make the best personal decision. If you recently turned 65 and are new to Medicare, sign up anytime within a seven-month window before and after your birthday. Those who want to keep their existing coverage don't have to submit anything. More than 81 percent of those in Medicare Advantage and 87 percent with stand-alone Medicare drug plans in 2013 stayed with their same insurance plans in 2014, according to PBS

What's the cheapest option? It depends on your needs. There are a wide range of costs among approved private Medicare plans. Low premiums aren't always the best choice, especially if they involve high co-pays or deductibles. Under Part A, the hospital deductible will be $1,260 for each benefit period. Under Part B, the standard monthly premium is $104.90 for those with taxable incomes of $85,000 or less and the deductible is $147 a year. Part C deals with Medicare Advantage plans, or private insurance that contracts with Medicare. They are chosen by about 16 million beneficiaries. Part D involves Medicare drug plans, with more than 38 millions people enrolled last year. The annual maximum deductible for drug plans in 2015 will be $320. Some Part D plan premiums are slated to increase by more than 50 percent, while others are falling, according to Dow Jones & Co.'s MarketWatch website. That's why beneficiaries need to shop around to ensure they are getting the best deal.

How do you compare Medicare plans? Look for what medicines are covered, premium costs, cost-sharing changes, deductibles, preferred pharmacies and any medication restrictions. For example, some Part D plans require beneficiaries to use a lower-cost drug before they will pay for a more expensive medication. The plans can also limit the amount of medication purchased at one time, according to U.S. News & World Report.

Do I need to worry about Medicare scams? Yes. The open enrollment period is a ripe time for scam artists who pose as employees from the Centers for Medicare & Medicaid Services, the federal agency that oversees the Medicare program. They work by calling Medicare beneficiaries and requesting their Social Security number, bank account numbers or other personal information to allegedly issue a new Medicare card. But you should never provide such information over the phone to a stranger calling your home. “It’s illegal for someone to call and ask for your Medicare number, Social Security number, or bank or credit card information,” according to CMS. “A Medicare representative or a private insurance plan working with Medicare will never call and ask for this information, and we will never call you or come to your home uninvited to sell Medicare products.”