Retirement is a huge financial and lifestyle decision. Retiring successfully takes more than just telling your boss you're not coming in anymore. You need an end-to-end plan that will get you through a time period that may well measure in decades during which you'll no longer be drawing a paycheck or have the other benefits associated with working.

These five steps to making sure you're ready to retire will help you get much of the foundation in place you need to improve your chances of success.

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No. 1: Know what you'll get from Social Security

Your Social Security benefit is based on how much you earned while contributing to the program, how long you worked, and what age you are when you begin collecting benefits. Because it's such an individualized amount, the absolute best spot to go to find out how much you'll get is the Social Security Administration itself.

With an online My Social Security account set up on Social Security's website, you can get the absolute best estimate of what you can expect from the program once you retire. Just be sure to note the assumptions inherent in even Social Security's estimates, as your final payout amount will not likely be exactly the same as its projection.

No. 2: Have a plan for your healthcare

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Some companies offer their retirees access to health insurance, while others offer a stipend to help cover at least part of the cost of insurance. In most cases, though, once you retire, you're on your own for health insurance costs.

If you're at least 65 and are a citizen or permanent resident of the United States, you can qualify for Medicare. That helps cover many of the costs of healthcare, but only Part A generally comes without a premium attached, and even then, only for those who qualify.

If you're under 65, however, and don't have access to insurance through your former place of employment, you'll generally have to buy coverage through your state's marketplace. Premiums vary by factors such as what level of coverage you choose, your age, whether you smoke, and where you live. In addition, you may receive a subsidy depending on your income and household size.

No. 3: Choose how you'll take your pension (if you have one)

If you're fortunate enough to still have a pension or other form of guaranteed income above and beyond Social Security, be sure you understand the choices you have regarding how to take it. Often, pensions offer income strategies based on your life or the longer of your or your spouse's life. In addition, many pensions offer cash buyout options instead of a straight income stream.

Key to note is whether your pension is integrated with Social Security. If it is, your pension will back out some portion of your Social Security income from the amount it pays you. This is important to realize in advance so that you don't count on income you won't actually receive.

It's also important to understand whether your pension income will adjust for inflation over time or whether it's fixed for life. If your payout is fixed for life, note that what might feel like a sufficient payment early in retirement may not go nearly as far later.

No. 4: Make sure you have a retiree-friendly portfolio asset allocation

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If you need to rely on your portfolio for a portion of your retirement income, you need to ensure that you have at least some of your money in bonds or other higher-certainty assets than stocks. The reason for this is that once you start drawing money from your portfolio, it gets substantially harder to wait out a downturn in the market and still wind up OK.

On the flip side, you don't want too much of your money tied up in conservative assets, either -- particularly if you're expecting a long retirement. This is because over long periods of time, stocks have a better shot of providing the growth you need to keep up with inflation. How much you keep in stocks and how much you move to bonds depends significantly on your personal financial situation. Still, a good rule of thumb is to not keep money in stocks that you expect to spend within the next five years.

No. 5: Brainstorm ways you'd like to fill your days and weeks

In addition to the financial benefits you get from working, most jobs provide structure that keeps your days busy and gives you some sort of social interaction with suppliers, customers, and/or coworkers. While you may feel intense relief from the freedom early in your retirement, that may turn to boredom and depression unless you have a plan to fill your time with activities that are important to you.

Consider volunteering for an organization you financially supported during your working years or one you wanted to volunteer for but never had the time. You might also think about taking a low-stress retirement job just to make sure you have that structure and interaction that come with the job.

If you like to travel, retirement can be a wonderful opportunity to do just that. In addition, if you have family and friends you'd like to get reacquainted with, your retirement can be a great time to do that as well. Just be wary of the old quip that retirement is often a time of "too much husband and not enough money," and make sure you're finding the right balance in your togetherness with family and friends.

Get ready for your next great adventure

With a solid plan in place, retirement can be a wonderful time. Get your ducks in a row regarding the financial, health, and activity aspects of your plan, and you'll have a great foundation upon which to launch the next chapter of your life.