Most states in the United States levy a state income tax on their residents. This state income tax is in addition to the federal income tax levied by the Federal government.
The fortunate residents of seven no tax states are not subject to a state income tax. Those states are Alaska, Florida, Nevada, South Dakota, Texas, Washington, and Wyoming. The residents of two low tax states, New Hampshire and Tennessee, pay state income taxes only on their dividend and interest income.
In recent years the highest state income tax marginal rate was that of Vermont, with a maximum rate of 9.5%. (This is curious, since Vermont is adjacent to the low-tax state of New Hampshire).