If an employee is wondering how to get a W-2 from a previous employer, they need to contact their employer directly. Employers are required to mail copies of W-2 forms to their employees every year. However, if the employee cannot reach their employer, they can call the IRS at (800) 829-1040 and provide their personal information, including their EIN and SSN. The IRS will then send the former employer a reminder letter to mail the W-2 form to the employee.