Age 65 is a major milestone, and one worth celebrating. If you're turning 65 in the coming year, here are a few important things to be aware of.

1. You can enroll in Medicare -- but doing so might not make sense

Medicare eligibility kicks in at age 65, and your initial enrollment period begins three months before the month of your 65th birthday and ends three months after the month in which you turn 65. But if you're still working at age 65 and have health insurance through your employer, signing up for Medicare might not pay.

65th birthday candles lit

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Though Medicare Part A, which covers hospital care, is free for most enrollees, Part B, which covers doctor visits and diagnostics, charges enrollees a premium. And that premium could end up being more expensive than the premium you pay for private insurance through your employer, particularly if you get a generous subsidy.

The insurance plan you get through your job might also offer a better or wider range of coverage than what you'd get under Medicare, so if you have access to a great group health plan, there's no rush to enroll in Medicare the moment you become eligible.

Rather, wait for your special enrollment period, which will begin the month after you leave your job, or the month after your group health coverage ends -- whichever is sooner. That special enrollment period will last for eight months, though you'll probably want to sign up for Medicare as soon as your coverage under your former plan ceases.

2. You'll take a hit on benefits if you file for Social Security

Though you're allowed to file for Social Security at age 65 (in fact, you can do so as early as age 62), don't assume that it makes sense to sign up for benefits just because you're eligible for Medicare. You're not entitled to your full monthly Social Security benefits until you reach what's known as full retirement age. Depending on your year of birth, that age is either 66, 67, or 66 and a certain number of months. Which means that if you file for benefits at 65, you'll automatically reduce them by anywhere from about 6.67% to 13.34% a year, depending on your actual full retirement age.

Here's the kicker: Unless you withdraw your benefit application within a year and repay all the money you received to the Social Security Administration, the aforementioned reduction will remain in effect for the rest of your life. And that could seriously diminish one of your largest retirement income streams. Therefore, unless you're desperate for money come age 65, you might be better off waiting a year or two to claim your benefits. You can still, however, sign up for Medicare -- you don't need to be on Social Security to get health coverage under it.

3. You might be eligible for a host of senior discounts

Even if you're still working at age 65, once you reach that milestone, you're often eligible for a variety of senior discounts. These can include reduced-price meals at restaurants, lower rates at hotels, and cheaper tickets to museums and movies. It pays to research what senior discounts are available, whether you're retired or not. And if you are still working at 65, you can use your savings to boost your retirement fund, thereby securing a higher income stream for yourself later in life.

Turning 65 is something to celebrate, but while you're busy blowing out the candles on what's hopefully an impressive cake, keep the above points in mind. This way, you'll be well positioned to make some smart financial decisions in the coming year.