The Tax Cuts and Jobs Act introduced a 20 percent deduction for qualified business income to maintain rough “parity” between pass-through businesses and C corporations. However, the deduction fails to ensure parity and exacerbates existing distortions. Given the deduction’s impending expiration, lawmakers have an opportunity to consider alternatives―one of which is corporate integration, a set of policies designed to standardize business taxation. This report evaluates how integration affects parity by analyzing three model proposals: a comprehensive business income tax, a credit imputation system, and a shareholder allocation system.