You usually don't have to provide benefits to domestic partners
Q Could you confirm if we are required to cover domestic partners on medical, dental, vision, life, or disability benefits?
A Typically, spouses are afforded certain rights based on the marriage, including certain employment benefits. Domestic partnerships are rarely treated the same as marriages. As such, you are generally not required to cover domestic partners on medical, dental, vision, life, or disability benefits. Some states or local governments such as municipalities actually require you to provide such benefits to domestic partners. However, many states, including Utah, do not.
Sometimes employers elect to provide benefits to domestic partners voluntarily. You, as the employer, don't have to require proof or documentation of a domestic partner relationship before providing benefits. Nevertheless, most employers usually want proof before providing domestic partner benefits. In fact, your benefits providers may require it. In such cases, the employees will need to prove the relationship to enroll a domestic partner.