A Practice Note addressing issues that arise for employers in providing health benefits to employees' domestic partners and civil union partners. The Practice Note identifies various types of federal and state relationship recognition laws, summarizes the federal tax consequences of providing domestic partner health benefits, and discusses the effect of domestic partner status on other employee benefit programs, including cafeteria plans and medical expense reimbursement plans. The resource also addresses implications of the US Supreme Court's decisions in US v. Windsor (2013) and Obergefell v. Hodges (2015).