What is a Form W-2 and how do you read it?

If you earn at least $600 during the year from an employer, you can expect a W-2 form by the end of January.

Form W-2, or a "Wage and Tax Statement," reports the wages you earned during the prior year, as well as any income taxes, Social Security taxes and medicare taxes your employer withheld. This is an essential form to file your taxes as it often determines the size of your refund (or if you'll owe taxes).

A W-2 form reports vital information such as the income you've earned from your employer, how much your employer withheld in taxes, and information about certain benefits (such as employer-provided health insurance) for the previous year.

Your employer uses this form to report salary and wage information to the IRS, and sends a copy to you as well so you have the information you need to accurately file your taxes. You can receive multiple W-2 forms in a year if you've worked full-time for several employers and have earned at least $600 in wages from each of them.

When you file your taxes, the information on your W-2 will help you complete your tax return. If you're using online tax software, you might not need to input any numbers manually. For example, TurboTax supports automatic import of W-2 information from over a million employers. Alternatively, you can upload your W-2 from your computer or use the TurboTax app to snap a photo.

If you're looking for a more affordable solution (and don't think you'll need some of the more specialized features provided by some tiers of TurboTax, such as live, individual support with a tax professional) TaxSlayer is also a good choice for tax software. Besides highly competitive pricing, this software features paid plans that let you file for every tax situation — the only difference between tiers is the level of technical support and tax advice you receive. Plus, you can import your W-2s, and the software will autofill your income and wages.

Besides your income and withholding, the W-2 form tells you important information such as your retirement contributions, the amount your employer paid for your health insurance and how much you received in dependent care benefits.

Here's how to read your W-2 form:

• Boxes A to F show identifying information about you and your employer.
• Boxes 1 and 2 show the total taxable income your employer paid you and how much was withheld in federal taxes.
• Boxes 3 to 6 show how much of your pay was subject to Social Security and Medicare taxes — and how much was withheld.
• Boxes 7 and 8 apply if you earned tips and tell you how much of the tip income was subject to Social Security tax and the amount your employer allocated to you.
• Box 10 reports how much your employer paid you in dependent care benefits.
• Box 11 tells you how much you received in deferred compensation — or, as TurboTax explains, pay you get outside of tax-advantaged retirement plans for work performed in previous years, typically after leaving employment or retiring.
• Box 12 details other types of compensation or income reductions, such as a 401(k) plan or health savings account contributions, with a single or double-letter code corresponding to each. You can look up the codes in the W-2 instructions from the IRS.
• Box 13 shows whether you worked as a statutory employee (a contractor treated as an employee for certain tax purposes), participated in an employer-sponsored retirement plan or received sick pay from a third-party source, such as an insurance company.
• Box 14 is for information that doesn't fit into other boxes, like uniform payments, union dues and health insurance premiums deducted, to name just a few examples.
• Boxes 15 to 20 contain state and local income tax information.

The IRS requires that employers provide employees and the government with W-2s by Jan. 31. Typically, you can expect to get your W-2s in the mail, although some employers send out electronic versions.

You should receive a W-2 from every employer that paid you $600 or more during the year — unless you're an independent contractor, in which case you'll receive Form 1099 instead.

That means that by mid-February, you should have all your W-2s. If that's not the case, contact your employer. Your company's HR department might not have the right address on file, or you might have missed communication about online access to your tax documents. Either way, getting in touch with your employer should usually solve the issue.

If that's not the case, it may be a good idea to give the IRS a call at 800-829-1040. You'll need to provide your name, address, phone number, Social Security number and dates of employment. The IRS will ask for your employer's information too, including name, address and phone number. After the call, the IRS will contact your employer and request the missing W-2.

Remember that, even if you get an extension, your taxes are still due by Tax Day (typically April 15). You may have more time to submit all the required documents, but your estimated tax payment cannot be postponed. Make sure you have your W-2 well before then so you can file with time to spare.

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