In a world filled with health care complaints, being pleased with your Medicare coverage puts you ahead of the game. But being satisfied doesn’t mean there aren’t areas for improvement, and what worked for you in 2014 may not be right for 2015.

Though it’s difficult to know what the future holds, if you foresee events such as a surgery or changes in your prescription drug regimen, planning in advance with the right Medicare policy could help you save substantially on your medical bills.

Medicare open enrollment, which will last until Dec. 7, is a chance for all beneficiaries — even those who are pleased with their plan — to explore their options.

During this period, you can drop your current Medicare Advantage plan in favor of another, revert to Original Medicare, leave Original Medicare and opt for Advantage, add or change Part D prescription drug coverage, or purchase a Medigap or supplemental policy.

Changes made during the open enrollment period will take effect on Jan. 1.

But, I’m Happy — Why Should I Change?

The majority of Medicare beneficiaries are happy with their coverage. A 2012 study from the Commonwealth Fund revealed that only 8 percent of Medicare beneficiaries rated their coverage fair or poor, compared to 20 percent of adults with employer-based coverage and 33 percent with individually purchased policies.

Reviewing your current coverage doesn’t necessarily mean you’ll make any changes, but rather that you’re open to the idea that something better might be available.

Regardless of what coverage you have, you can search all Medicare plans, including prescription drug benefits — known as Part D Medicare — with the Medicare Plan Finder tool, or call 800-MEDICARE with questions.

If You Have Original Medicare

Original Medicare is the default category in which you are enrolled if you don’t select another option. This is coverage managed by the federal government and consists of Part A (hospital insurance) and Part B (medical insurance) coverage. Your policy is accepted anywhere that takes Medicare, and you don’t have to worry about seeing medical providers in a specific “network,” though you may be responsible for deductibles, coinsurance and a premium for Part B coverage.

Read through this year’s “Medicare & You” handbook on Medicare.gov to understand your coverage, including what’s covered under free preventive services (such as mammograms and flu shots) and how much you’ll pay out-of-pocket for certain treatments, exams and procedures.

Though most people don’t pay a premium on Part A coverage, Part B is another story. Costs are not changing in 2015, however, and most annual Part B premiums will remain at $104.90. Inpatient hospital deductibles for Part A are rising slightly, to $1,260, as are coinsurance payments.

Understand that Original Medicare doesn’t cover everything, and you may want to consider a supplemental policy for needs such as prescription drugs, eyeglasses, dental care (including dentures), hearing aids and exams, and long-term care. Another option is a Medigap policy, which can help with out-of-pocket expenses such as deductibles, copays and coinsurance. Open enrollment is the time to sign up for these policies.

You may consider switching to Medicare Advantage (also known as Part C) if you want a single plan that includes services such as prescription drug benefits, dental or vision coverage. You can also use this opportunity to see what Part C plans may fit your needs; browsing Medicare Advantage plans doesn’t come with an obligation to buy.

If you’ve reviewed the information and want to stay with Original Medicare, no action is required on your part; your current coverage will extend into 2015.

If You Have Medicare Advantage

Medicare Advantage includes both Part A and Part B coverage and is managed by private insurance companies rather than the government. These plans include PPOs and HMOs and resemble other private insurance plans sold to people of all ages. Like those plans, Medicare Advantage plans can vary dramatically in costs and coverage.

Under Medicare Advantage, you generally have to visit in-network medical providers or risk paying more out of pocket. You’ll also pay a monthly premium and be subject to deductibles, copays and coinsurance.

Unlike Original Medicare, most Part C plans include prescription drug coverage. Some may also offer dental and vision benefits not available through Original Medicare. In addition, Medicare Advantage plans have annual caps on out-of-pocket expenses.

You should have already received a letter from your insurance company outlining any changes you can expect in 2015. If you haven’t received an Annual Notice of Change or Evidence of Coverage document from your insurer, call to request a copy. These notices will include any cost or coverage changes that you should be aware of, so read them and the “Medicare & You” handbook carefully.

Some insurers may raise rates slightly for 2015, while some are expected to cut benefits. Other beneficiaries may find their provider network narrowed as insurance companies look for creative ways to cut costs.

Analyzing your health care needs for next year and looking at a variety of plans during open enrollment will help ensure you have the best coverage for 2015. In addition to using the Medicare Plan Finder at Medicare.gov, you can browse Part C plans on the websites of private insurers.

If You Have Part D, Prescription Drug Coverage

While Medicare Advantage plans typically include their own prescription drug coverage, under Original Medicare, you must purchase Medicare Part D separately. This insurance comes from private companies with costs and coverage varying from policy to policy.

If you already have Part D, review your current coverage and additional available plans even if you were pleased in 2014. You may find price increases or coverage limitations on tap for 2015 a significant motivator for finding a new policy.

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Satisfied With Your Medicare? Why You Should Still Review Your Plan originally appeared on usnews.com