Time is running out to switch or ditch your Medicare Advantage Plan

Don't like your Medicare Advantage Plan? You have a couple weeks left to do something about it.

During a window that opened January 1 and will close March 31, enrollees who are unhappy with the choice they made during Medicare's fall open enrollment period have two options: ditch it for original Medicare or switch to a different plan.

"Sometimes people just chose the wrong plan," said Danielle Roberts, co-founder of insurance firm Boomer Benefits in Fort Worth, Texas. "Maybe they thought their doctor was in network and then discovered the person wasn't."

"Sometimes people just chose the wrong plan. Maybe they thought their doctor was in network and then discovered the person wasn't." -Danielle Roberts, Co-founder of Boomer Benefits

Separately, but also possible until March 31: If you missed your initial Medicare enrollment period and don't qualify for an exclusion, you can sign up now. In this case, coverage won't start until July 1.

If you're among those who already have an Advantage Plan and want to change your coverage, there are some things to keep in mind.

show chapters How American health care got so expensive    12:55 PM ET Wed, 13 Feb 2019 | 14:58

For starters, because you only get one shot at this, make sure you know what you're signing up for if you choose another plan. That includes ensuring that your medications are covered and that your favorite doctors or other providers are in-network.

Roberts said that even if you see your doctor listed on a plan's online directory, you should confirm that status directly with their office because those listings can be outdated or contain errors.

"When you call your doctor, ask specifically if they are in network for your particular plan," she said. "Don't just say the name of the insurance company."

More from Fixed Income Strategies:
Now may be the time for bonds in portfolios
Surprising spending truths could upend your retirement
Financial worries prevent earlier retirement for many

If you're planning to drop your Advantage Plan in favor of original Medicare — which consists of Part A hospital coverage and Part B outpatient coverage — you also likely need to get a standalone Part D prescription drug plan. This often was included in your Advantage Plan, and life-long penalties can be applied if you go more than 63 days without coverage.

Additionally, if you're planning to get a supplemental Medicare plan — called Medigap — to pair with original Medicare, be aware of additional rules for applying. These policies help cover costs such as deductibles, co-pays and co-insurance.

When you first enroll in Medicare (typically at age 65), you get six months when you're guaranteed Medigap coverage. That is, you can get a policy without the insurance company nosing through your health history and deciding whether to insure you.

Sign Up for Our Newsletter Your Wealth Weekly advice on managing your money SIGN UP NOW Get this delivered to your inbox, and more info about about our products and services.
By signing up for newsletters, you are agreeing to our Terms of Use and Privacy Policy. .investigation-wrapper .description{ text-align:center; padding-bottom:15px; } .nl-privacy{ font-size: 10px; padding-top: 20px; display:block; } .wildcard .investigation-wrapper { -webkit-box-shadow: 0px 0px 4px 0px #999999; /* Android 2.3+, iOS 4.0.2-4.2, Safari 3-4 */ box-shadow: 5px 5px 5px 0px #999989; } .subsection .investigation{ background: #efefef; border-radius: 3px; padding: 10px 20px 20px 20px; } .investigation small{white-space:normal;} .subsection .investigation h1{ text-transform: uppercase; text-align: center; font-family: "Gotham Narrow Ssm 5r"; margin-bottom: 0px; padding-bottom:0px; font-size: 18px; margin-top: 10px; word-spacing: 1.5px; color: #333333; } .subsection .investigation .headline_title { font-size: 28px; padding-top: 20px; display: block; font-family: "Gotham Narrow Ssm 7r"; padding-bottom:5px; } .subsection .email-info { background: rgba(74, 144, 226, 1); max-width: 140px; margin: 0px auto; text-align: center; padding: 6px 1px; color: #fff; border-radius: 5px; } .subsection .email-info { color:#fff; } .subsection .email-info:hover{ background: #2077B6; } body .subsection.investigation-wrapper{overflow:visible;}

After that, it can be a different story. In most states, you have to go through medical underwriting. If you're in this situation and have underlying health issues, you could be charged more for a policy or denied coverage altogether.

"Ideally, you applied for Medigap early in this enrollment period," Roberts said. "It could take a few weeks to underwrite you."

Special exceptions to this rule include when your Advantage Plan is no longer available or when you're within the first year of trying an Advantage Plan for the first time and decide to ditch it, Roberts said.

Subscribe to CNBC on YouTube.