The Tax Cuts and Jobs Act (TCJA) triggered the IRS to revise the federal Form W-4. Among a number of changes, the most significant was the removal of federal withholding allowances.
This change posed a challenge to states that relied on the federal Form W-4 for their own state withholding. As a result, many states revamped their state withholding forms and now require taxpayers to submit both a state and a federal withholding form to ensure their state income withholding is accurate. But, it depends on the state. In some cases, just the federal form will do the trick.
Below is a chart summarizing W-4 requirements by state. Just remember, state requirements change often so you should always double check this information against your state's Department of Revenue website. To download a print-friendly PDF version, click on the image below.