STATE TAX RATES are lower this year for corporations in seven states and the District of Columbia. Arizona reduced its corporate income tax rate from 6.5% in 2014 to 6.0% in 2015. Automatic rate reductions were set in motion in 2011 that will lead eventually to a 4.9% corporate tax rate in 2017.

The District of Columbia reduced its corporate income tax rate from 9.975% in 2014 to 9.4% in 2015.

In Indiana, the rate went from 7.5% to 7% and will fall to 6.5% after June 30. The rate will be reduced by 0.5% a year through 2016, and then fall by another 0.25% a year until it reaches 4.9%.

The corporate income tax rate in North Carolina fell a full percentage point, from 6% in 2014 to 5% in 2015. Future reductions are expected, but will depend on general fund tax collections the year before.

Rhode Island reduced its corporate income tax rate from 9% to 7%.

In New Mexico, the rate fell from 7.3% to 6.9%. The rate will continue to fall by 0.3% to 0.4% a year until it settles at 5.9% in 2018.

The Texas margin tax for retail and wholesale entities fell from 0.5% to 0.475%. The rate for other entities fell from 1% to 0.95%.

Keith Martin in Washington