Internal Revenue Code Conformity by State
Author: Alice Gilman
For administrative convenience, some states that require employers to withhold income taxes from employees' wages tie their definition of wages to that of the federal Internal Revenue Code (IRC), which causes them to be affected by any changes made to the IRC. Many states, however, follow an earlier version of the IRC that was in effect as of a specific date. But no matter which version of the IRC a state follows, there may be important exceptions applicable to certain types of income or benefits. Because the definition of wages is the basis for calculating state taxable income, it is important for an employer to know which definition a state follows.
The following chart summarizes which version of the IRC each state follows in defining taxable wages for withholding purposes. States that do not have an income tax are marked N/A.