If you're a Medicare user, now is the time to consider whether you'd like to make any changes to your coverage. Medicare's "Annual Coordinated Election" (open enrollment) period is coming up October 15 through December 7. For most policyholders, it's the one time of the year when plan changes may be made.

Medicare is the primary health insurance program for Americans age 65 or older. Participants have their choice between traditional (original) Medicare and a Medicare Advantage plan.

Original Medicare consists of hospital (Part A), medical (Part B), and outpatient prescription-drug coverage (Part D). These parts can also be supplemented by one of several "Medigap" policies to help cover items not included in Parts A, B, or D.

Medicare Advantage plans (also known as Part C), provided by Medicare-approved private health insurance companies, often package all that traditional Medicare covers in Parts A, B, and D, and sometimes also include dental, vision, and/or hearing benefits.

The changes you can make

During open enrollment, Medicare users can:

  • switch from original Medicare to a Medicare Advantage plan, or vice versa;
  • move from one Medicare Advantage plan to another;
  • switch from one Part D plan to another;
  • drop Part D;
  • or, enroll in Part D for the first time.

If you have a Medigap policy that you wish to change, check with the private insurance company that issued the policy.

If you're satisfied with your current Medicare coverage, you don't need to do anything. You will be automatically re-enrolled in the plan for 2015.

If satisfied, shop anyway

Even if you're happy with your current plan, it may be worth the effort to reevaluate your coverage. There are many reasons to do so.

The cost and benefits of Medicare health and prescription drug plans can change each year (so always read those boring "Evidence of Coverage" and "Annual Notice of Change" materials your plan sends each year).

Maybe your Advantage plan has decided to leave Medicare. Or maybe your doctor has decided to stop accepting the type of Medicare plan you use (be sure to check).

Another important reason to compare plans is if your health has changed — perhaps you've been diagnosed with a new health condition or prescribed a new medication. Making sure you have the right prescription-drug plan can save you a substantial amount of money.

There are lots of choices when it comes to prescription drug coverage. In 2013, the number of Part D plans ranged from 23 in Alaska to 38 in Pennsylvania. Different plans can charge widely different co-pays, even for the same drug.

Help is available

The online Medicare Plan Finder is an easy-to-use, well-designed tool that will do much of the comparison shopping work for you, helping you find the plan that covers the drug(s) you need for the lowest out-of-pocket cost. Enter the drugs you take, the dosages, and the pharmacy you use. The Plan Finder will look beyond the premium cost, factoring in co-pays and deductibles to get to a total annual estimated drug cost. It also rates each Medicare Advantage plan based on an assessment of its quality and performance.

Another popular site for plan comparisons is PlanPrescriber.com. To talk with someone about choosing the best plan, contact your state's health insurance-assistance program.

You can make changes to your coverage by visiting Medicare.gov, calling 800-633-4227, or by contacting your Medicare Advantage plan of choice. You should receive confirmation of your changes within two weeks. If you don't, contact Medicare to confirm your coverage.

If you miss the open-enrollment season and are dissatisfied with your Medicare Advantage plan, you'll have one more opportunity to get out of the plan. The annual Medicare Advantage Disenrollment period runs from January 1 to February 14. During that time, you won't be able to switch from one Advantage plan to another, but you will be able to switch from your Advantage plan to original Medicare while also picking up a Part D prescription-drug plan.

One final word of advice. Be on guard against Medicare scam artists. The annual Medicare open-enrollment season is also open season for people who prey on Medicare users. In one common scam, someone claiming to represent Medicare will call or even knock on your door stating that they need to replace your Medicare card and asking for your Medicare number (which is your Social Security number!). Don't fall for it. Medicare will never call you asking for your number, nor do Medicare representatives knock on doors.

For more details about Medicare, download "Medicare & You."