Generally, the IRS will keep between 25 and 50% of your disposable income. Disposable income is the amount left after legally required deductions, such as taxes and Social Security (FICA). However, there are exceptions to this rule that could protect part or all of your income from the wage garnishment. Under federal law, most creditors are limited to garnishing up to 25% of their disposable salary.
However, the IRS isn't like most creditors. Federal tax liens take precedence over most other creditors. The IRS is only limited by the amount of money it must leave to the taxpayer after garnishing the salary. Like most creditors, the Internal Revenue Service (IRS) has the power to garnish your salary if you have a tax debt.
However, unlike most other creditors, the IRS can garnish your salary without first obtaining a judgment, and the amount you can collect is usually greater than what regular creditors can take.