Your chances of a secure retirement will improve if you start checking items off your to-do list at least a year out. Among the issues you'll face is Medicare.

You're eligible for Medicare at age 65, and you can sign up without penalty any time from three months before until three months after the month of your 65th birthday. (If you claimed Social Security benefits early, you'll be automatically enrolled at age 65.) Medicare Part A covers hospitalization and is premium-free, so there's generally no reason not to sign up as soon as you're eligible. (To enroll, go to www.ssa.gov.)

Part B covers outpatient care, including doctors' visits. It costs $121.80 a month for singles with an adjusted gross income (plus tax-exempt interest) of $85,000 or less ($170,000 for couples) who sign up in 2016. Above those income levels, you'll have to pay $170.50 to $389.80 per month. You'll also have to pay a surcharge of $12.70 to $72.90 a month on top of the premium for Part D prescription drug coverage.

If you don't sign up for Part B during the seven-month window, and you do not have coverage through your current employer, you may have to pay at least a 10-percent penalty on premiums permanently when you do sign up. If you work for a company with fewer than 20 employees, your group coverage generally becomes secondary to Medicare at age 65, so you should sign up for both Part A and Part B — otherwise, you may not be covered at all.

Employees of larger companies can choose to keep group coverage while still working and hold off on signing up for Part B. But you must sign up for this coverage within eight months of leaving your job or you'll pay a penalty.

Medicare doesn't cover everything; you may want to pick up a Medicare supplemental policy (Medigap), as well as a Part D policy, for prescription drugs. There are 10 types of Medigap policies, each identified by letter; the average price for the most popular, Plan F, is $172 a month, according to Weiss Ratings. For Part D, the average monthly premium is $34 in 2016.

Rather than combine three plans, you could join Medicare Advantage, offered by private insurers. Advantage plans cover the same services as Medicare and include prescription drugs. They typically have lower premiums than a Part B/Part D/Medigap combination but higher co-payments and more restrictions.

Jane Bennett Clark is a senior editor at

Kiplinger's Personal Finance magazine.

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