Maybe you've held down the same job for several years and have finally grown tired of it. Or maybe you like your job, but just got offered a new one with a higher salary and more compelling work. There are plenty of good reasons to leave a job, but before you do, make sure to cross the following items off your list.

1. Write an official resignation letter

Even if you have a great relationship with your boss, you should make a point of writing a formal resignation letter as you gear up to leave your job. This way, your employer has that note on file, and you'll be able to clearly define when you'll be leaving (though you should always aim to provide at least two weeks' notice before separating willingly from an employer). Just as importantly, your resignation letter is your chance to go out on a professional note, and if you fill that letter with statements of gratitude, it'll help you look good in your company's eyes (and perhaps help soften the blow of your departure).

Professionally dressed man standing at desk, holding cardboard box containing personal effects

Image source: Getty Images.

2. Swap contact information with colleagues

Chances are, you have a number of colleagues you enjoy spending time with at the office or want to stay in touch with for professional purposes. It's always smart to have a way of reaching those people outside of their work email accounts or office-based landlines, so once you've submitted your resignation letter, let those people know you're leaving and take down their personal contact info.

3. See if you're entitled to unused vacation time

Depending on your company's time off policy, you may be entitled to cash out unused vacation days upon your departure, even if the decision to leave is yours alone. Similarly, you may be entitled to get paid for sick days you accrued. Read up on your employer's policy, or talk to someone in your human resources department who can help you determine what last-minute compensation, if any, you're entitled to.

4. Figure out health insurance

If you've been getting health insurance from your employer, leaving your job will mean losing that coverage. Now if you're headed to a new job whose health benefits kick in right away, this won't be a problem. But if you will be looking at a coverage gap, you'll need to solve for that, since walking around uninsured for any period of time is a highly risky move.

If you need health insurance for just a month or two during that transition period, COBRA may be your best bet. With COBRA, you can retain your former employer's health plan, the only difference being that you'll need to pay your premium costs yourself, as opposed to counting on your employer to subsidize them. The result could be pretty expensive, but if you're only looking at a brief coverage gap, the convenience may be worth the cost.

5. Decide what to do with your 401(k)

If you had a 401(k) plan through work, you'll generally have the option to leave your money where it is, even once you're no longer an employee. But doing so may not be ideal, in which case it pays to have a plan for where you'll put your retirement savings. Now if you have another job lined up and you know that employer has its own 401(k), you can roll your money from your old plan into that new one directly. If you don't have a replacement job secured, or your new company doesn't offer a 401(k), then you can roll your old 401(k) into an IRA.

Switching jobs is a big deal. Before you leave your current employer, be sure to tackle these key items. Doing so will allow you to move on in a smooth, stress-free fashion.