Medicare's open enrollment period is right around the corner, which means you'll soon need to decide whether to retain your current coverage or make changes that result in more affordable healthcare. Many enrollees find open enrollment stressful, but if you check off each point on this list, you'll increase your chances of walking away with the right coverage for 2020.

Step 1: See what changes your current plan has in store

Though Medicare Parts A and B are universal, Part D, which covers prescription drugs, consists of numerous plans that you choose from. All Part D plans follow a formulary that places different medications into different tiers. The lower the tier your prescriptions fall under, the less money they cost you.

Diamond-shaped sign reading Open Enrollment Ahead

IMAGE SOURCE: GETTY IMAGES.

Part D plan formularies, however, can change from year to year, so it's important to read up on what's in store for your plan before deciding whether or not to keep it. For example, if a drug you take regularly is pushed into a higher tier than it's currently in, your costs are likely to go up, and that may not work for you.

All plans are required to send participants a notice of change letter that summarizes shifts in things like medication coverage and cost-sharing. Read that letter carefully to understand what changes you're in for, and if they hurt you financially, consider making a switch.

The same holds true if you're enrolled in Medicare Advantage instead of original Medicare. Pay attention to changes in your plan to ensure that it still works for you.

Step 2: Assess your prescription needs

Even if your Part D plan doesn't change all that much, it could be that your prescription needs have changed since you first signed up for it. Maybe you no longer take the same medications regularly, or your doctor recently switched you from a brand-name drug to a generic. Before you lock in a plan for 2020, figure out what type of coverage you actually need, and then see how to get it most affordably.

Step 3: See what plans are available in your area

Medicare Advantage plan availability differs from state to state in terms of number of choices and affordability. The same holds true for Part D plans. Therefore, you'll need to see which options are on the table for you, and then evaluate each one to land on the right choice.

If that process seems overwhelming, Medicare's plan finder tool can help. That tool lets you plug in information about yourself, including your ZIP code and prescription needs, so it can identify plan options that may be suitable for you. Just as importantly, the tool includes plan ratings that can help you compare your options and see how satisfied current enrollees are with them.

Chances are, healthcare is one of the greatest expenses you're grappling with in retirement. Even if you saved well for your golden years ahead of time, you may already be struggling to keep up with your medical costs. The choices you make during open enrollment will dictate how much money you spend on healthcare in the coming year, so give yourself ample time to land on the right decision. Open enrollment begins on Oct. 15 and lasts until Dec. 7, so you have more than seven weeks to find the right Medicare plan.