Following the U.S. Supreme Court's decision in United States v. Windsor on June 26, 2013, the Internal Revenue Service (“IRS”) stated that qualified retirement plans (e.g., profit-sharing, 401(k), pension plans, etc.) must recognize statutory spousal rights for same-sex spouses and that such plans must also recognize same-sex marriages based on the laws of the “state of celebration” rather than the “state of residence” beginning September 16, 2013. Such statutory spousal rights may include, but are not limited to, the right to consent to a participant's waiver of a qualified joint and survivor annuity.  In its recently issued Notice 2014-19 (“Notice”), the IRS provides additional guidance on recognition of same-sex spouses in qualified retirement plans.  In the Notice, the IRS provides that qualified retirement plan operations must reflect the outcome of Windsor as of June 26, 2013.  A retirement plan will not be in violation of the Internal Revenue Code (“Code”) for failing to recognize the same-sex spouse of a participant as a spouse before June 26, 2013.  Additionally, the Notice provides that qualified retirement plans that recognized same-sex marriages based on the “state of residence” (rather than the “state of celebration”) prior to September 16, 2013, would not be in violation of the Code.  Qualified retirement plan sponsors may amend their plans retroactively to adopt changes effective prior to the date of the Windsor decision but the IRS warned that such changes may inadvertently “trigger requirements that are difficult to implement retroactively and may create unintended consequences.”  Any qualified retirement plan that defines a spouse with a reference to the Defense of Marriage Act or strictly as being an opposite-sex spouse must be amended.  No amendment is necessary if the terms of the plan are consistent with the Windsor ruling (e.g., the plan utilizes a term for “spouse” without any distinction between a same-sex spouse and an opposite-sex spouse).  Any required amendments must be adopted by the later of (i) the plan’s applicable remedial amendment period, or (ii) December 31, 2014.  It is recommended that all qualified retirement plan sponsors review the terms of their plans to determine whether an amendment is needed to comply with the Notice requirements.  Also, although the Notice does not apply to non-qualified plans such as employment and severance agreements, and stock incentive plans, which often include a definition for “spouse,” employers may need to amend such plans and agreements to conform to any revisions made to a qualified retirement plan that may be referenced in the non-qualified plan.