Now that the U.S. Supreme Court has declared Section 3 of the Defense of Marriage Act (DOMA) unconstitutional, everyone seems to be an expert on what it means.

I will be the first to admit I am not a DOMA expert, but I am among those who want to prudently assess the guidance that federal agencies are required to publish, in order to comply with governance for employer compensation and benefit programs.

Here are some technical issues upon which I am speculating (note my formal admission of speculation) that we will need guidance:

Retroactive applicability of DOMA for FICA taxes on health benefits. If I am an employer with employees in any of the 13 states or the District of Columbia that permit same-sex marriages, do I have to refund 2013 Federal Insurance Contributions Act (FICA) taxes withheld on premiums my employee paid to cover his or her same-sex spouse under the company's health insurance plan? What about FICA taxes withheld for tax years before 2013? Sounds like a lot of work if I have to do this.

Question: What will I have to do for the 37 states that have yet to recognize same-sex marriage?

Validation of marriages. Am I going to have to ask for evidence of a marriage certificate from employees with same-sex spouses if I have not been asking for evidence of marriage in the past? What if my employee(s) were married outside the United States?

DOMA and ACA. Although my employer-sponsored healthcare plan is likely to be superior to, and more tax-efficient than, the plans that will be offered on the state healthcare exchanges under the reforms associated with the Patient Protection and Affordable Care Act (ACA), do I have any obligation to tell my employees that by filing a joint federal tax return after they are married, they may forfeit any healthcare exchange premium tax credits they were anticipating because their joint modified adjusted gross income (MAGI) will increase?

I'll be thinking about more of these issues from a practical standpoint as I await the required guidance from federal agencies. Meanwhile, I'll just watch the Milliman Healthcare Town Hall countdown clock hurtle toward midnight on October 1, 2013.