State tax filing

Did you enter both states in your Federal Section for your W2? This information will pull over to the state returns. 

As a part year resident, Nebraska will tax your entire annual income and then determine the percentage of total income attributed to Nebraska and you will pay that percentage of tax in Nebraska. 

For instance if 50% of your entire income was earned in Nebraska, you will pay 50% of the tax calculated on your entire income.

This is all calculated on Schedule III.  Also, Nebraska's income tax rate is much higher than Arizona's.