State tax filing

That actually depends upon the source of your income and whether it was earned as an employee or a contractor.

If you earned the income for the other states as an employee of the company on a W-2 form, your income would be sourced to New York.

Your work as a contractor will be dependent upon how your income is earned and the filing requirements for each state.

Ohio requires nonresidents to file a tax return for any income from Ohio-sourced income from doing business in Ohio.

Ohio filing requirements for Nonresidents

Nebraska taxes all nonresidents on any income earned from Nebraska sources.

NE tax booklet with full instructions

Therefore, if all of your income from Ohio and Nebraska is related to your work as a contractor and reported on a 1099 form, you will need to file nonresident returns as well for both of these states.  Please note, you will be able to claim a credit on your New York resident return for any income taxed in these states to ensure you are not taxed twice on the same income.