This legislation aims to modernize the Internal Revenue Code to ensure that all legally married couples, including same-sex couples, are treated equally under tax laws. By eliminating ambiguity and discrimination, the bill affirms the rights and benefits of same-sex couples, aligning their treatment with that of heterosexual couples. Key provisions include replacing gender-specific terms such as "husband and wife" with inclusive language like "married couple" or "spouses" throughout the tax code.