Original Medicare vs Medicare Advantage: what's the difference?

There are many differences. Here are several....

• Deductibles, copays, and coinsurance amounts are all different between the two.
• Medicare Advantage has an annual out-of-pocket maximum to protect you against catastrophic costs, while Original Medicare does not.
  
• Most Medicare Advantage plans include prescription drug coverage. With Original Medicare, you have to purchase Part D for drug coverage.
• In addition to cost differences, there are non-financial issues to consider such as choice of healthcare provider and pre-authorization requirements for certain services under Medicare Advantage.

Here's a two-page summary from the Medicare Rights Center that will help you compare and contrast the two: 
Differences Between Original Medicare and Medicare Advantage Plans
Beyond that, you may wish to get in touch with your State Health Insurance Assistance Program (SHIP). It's a confidential, free service and they can help you decide which direction is best for you.

Medicare Advantage plans are administered by private insurance companies and they must offer a level of benefits that is equal to or better than original Medicare.  The trade-off is that you will realize the most benefits if you stay within network and going out-of-network could be hazardous to your finances.  These plans are also very regional, some plans travel better than others but you will have to consider that when evaluating plans.

Depending on where you live, you may be better served to talk to an independent insurance agent that deals with Medicare Advantage, Medicare Supplements, and Medicare Drug Plans.  Many SHIP counselors are not as well-versed in Medicare Advantage plans because of the various certification requirements.