As stated in the Answer below, your employers have until the end of January to provide you with a W-2.
Your pay stubs probably do NOT have the information that is on your W-2. The IRS will have a copy of the W-2 and compares your tax data with the data they have received from your W-2. If your return has incorrect tax data the IRS will either reject your tax return outright or will hold the tax return for several weeks or months to investigate.
