Massachusetts U-4 is a form required by Massachusetts state law for employers to complete for every employee. It is used by the state to administer certain taxes, including unemployment insurance, withholding taxes, and personal income tax. The form is primarily used to report wage and salary information to the state. It contains information such as the employee's name, Social Security number, the employer's name and address, and the employee's wages over the course of the year. It also includes information about the employee's deductions, such as taxes, health insurance premiums, and retirement contributions. There are two types of Massachusetts U-4 forms: the employer version and the employee version. The employer version must be completed by the employer and submitted to the state, while the employee version is used by the employee to track their own information and provide it to the employer when requested.