In the post-Windsor, post-Obergefell world, the Internal Revenue Code needs to be revised to take same-sex marriage into account. The ABA Section of Taxation has submitted to the IRS comments on proposed regulations defining terms related to marital status in the Internal Revenue Code. The principal drafter of the comments was Anthony Infanti (Pitt), chair of the Teaching Taxation Committee of the ABA Section of Taxation. Substantive contributions came from Pat Cain (Santa Clara), David Herzig (Valparaiso), Ted Seto (Loyola Law School, Los Angeles), and others (with some minor comments from me). Tony Infanti's leadership was absolutely key.
One important aspect of the comments is the recommendation that the IRS recognize domestic partnerships, civil unions and similar relationships for federal tax purposes. The Comments explain that "recognizing these alternative relationship statuses for federal tax purposes would better fulfill the Service’s professed purposes in issuing the Proposed Regulations, would result in fairer treatment of similarly situated taxpayers, would render tax considerations neutral in choosing between the different relationship statuses, and would better accord with the reality that several states already treat these relationships as marriages for purposes of their laws."
You can read the Comments here.