How the Supreme Court will rule on the challenge to the health care reform law remains an unanswered question.

The only safe conclusion that can be made at this point is that the high court will hand down its decision by the end of June.

It also probably is safe to conclude that the justices will either find that the Patient Protection and Affordability Care Act's individual mandate is constitutional or unconstitutional.

If the latter, the Supreme Court also likely will decide whether or not to strike down the entire law.

Even with so much uncertainty, it would behoove employers to start thinking now about their plan of action if the court does strike down the entire law. As we have reported, employers have a whole host of issues before them. Among significant concerns are whether to keep plan design changes that they had to make to comply with the law's requirements, even if they no longer were compelled by law to do so.

Even more important, we would hope that federal regulators and Congress would respond quickly and appropriately should the Supreme Court overturn the law.

For example, the law required employers to amend their health care plans to offer coverage to employees' adult children up to age 26, with the coverage provided tax-free. Previously, the coverage was tax-free for employees' children up to age 19, or to 24 for children who were full-time students.

If the law were struck down, presumably that would mean that the coverage that was provided in some cases, such as to 25-year-olds, would be taxable.

We shudder to think of the time, expense and confusion that would result if employers had to issue to affected employees new W-2s to reflect the change in tax status of the health insurance coverage due to a Supreme Court decision.

We would hope that regulators—or, if they lacked the authority, then Congress—would intervene quickly to make it clear that employers who complied in good faith with the law should not be required to make retroactive changes.

And we also would hope that lawmakers—this time on a bipartisan basis—begin work on a new reform measure that could pass legal muster and be in the national interest.