Complex sentence: Of the 28 states that offer tax credits, 26 make them either transferable or refundable, which means the state will pay the production company the balance in excess of the company's owed state tax.
Split into simpler sentences: Of the 28 states that offer tax credits, 26 make them either transferable or refundable. Refundable credits are such that the state will pay the production company the balance in excess of the company's owed state tax.