State tax filing

No. The OK government clearly defines this as a state tax credit refund. The taxability is determined by individual circumstances. See Title 710 Chapter 50-15-119 Parental Choice Tax Credit. This is new and there will undoubtedly be lawsuits to determine boundaries.  The latest state legislation, Oklahoma Parental Choice Tax Credit Legislation shows it is not taxable to OK.

I see two ways to treat this: 

1. As a state refund -  may or may not be taxable depending upon itemization in prior year.

2. As a taxable grant. - the safest method, pay federal tax Enter in box 6 as a taxable grant

The second option seems the most reasonable to survive this without audits or backlash. New laws are often made without thinking through all the possible effects.