By Rick Yandle, Esq., CPA — federal criminal & civil tax defense
Anyone who has watched children play knows the rule of "the floor is lava": you cannot step just anywhere, and one wrong move ends the game. There is a version of that game in federal tax law, and divorcing spouses land in it more often than they realize. Some moves that look harmless — signing off on a joint tax case, agreeing to a resolution to make it go away — quietly burn the floor under a spouse's later options.
The relief, and the trap
Section 6015 gives a spouse a way out of joint and several liability for a jointly filed return. It provides three potential forms of relief: traditional innocent-spouse relief for a spouse who did not know and had no reason to know of an understatement; allocation of a deficiency for qualifying divorced or separated spouses; and equitable relief where holding the spouse liable would simply be unfair. It is one of the most important protections in the collection-defense toolkit, and for the right client it can be the difference between financial ruin and a fresh start.
But relief under Section 6015 comes with a trap that has ended many otherwise-strong cases before they began: res judicata. Under Section 6015(g)(2), a final court decision for the same taxable year is conclusive. A later innocent-spouse claim can sometimes escape preclusion if relief was never at issue in the earlier case — but not where the requesting spouse meaningfully participated in that prior proceeding and could have raised the claim there. In that situation the prior decision is final, and the door is closed.
A recent Tax Court memorandum decision, Vettel v. Commissioner, T.C. Memo. 2025-110, drove the point home. A spouse sought innocent spouse relief after years of unreported foreign income came to the surface. The problem was not the merits of her knowledge argument. The problem was procedural. She had already been through the couple's earlier Tax Court deficiency case — represented by counsel who negotiated the settlement, kept informed and copied on the correspondence, even reviewing draft innocent-spouse materials while that case was still pending — and she signed the stipulated decision that resolved it. Weighing all of it together, the Tax Court found she had meaningfully participated, and res judicata barred her from later obtaining Section 6015 relief for those years and liabilities.
She may well have been able to argue, truthfully, that she had not known about the offshore accounts when the returns were filed — and the court did not say otherwise. It simply never reached that question. Once the earlier decision was entered with her meaningful participation, the merits no longer mattered. The floor was lava.
Why this is a family-law problem, not just a tax problem
One clarification, because it matters: Vettel itself was not a divorce case — the spouses were still married when her innocent-spouse claim was tried — which underscores that this trap is not unique to divorce. But it is in family-law contexts that it most often springs. The fatal move usually happens in a different proceeding, often while the marriage is dissolving and everyone just wants the tax mess resolved. A joint deficiency case gets settled. A stipulated decision gets signed. The spouse who will later need innocent spouse relief is, at that moment, a participant in the very proceeding that will bar her from getting it.
If you practice family law and your client has joint tax audit or deficiency issues, the timing and sequence of what happens in the tax case can make or break your client's options for relief later. This is one of those "floor is lava" moments — don't jump here, but don't jump there either. Sometimes the best move is to slow the tax case down, get a qualified tax litigator involved, and preserve the Section 6015 route before anyone signs anything.
Practical guardrails
First, treat a joint Tax Court case as a decision point for the innocent spouse's future rights, not just a liability to be settled. Second, be wary of letting a client meaningfully participate in resolving a liability she may later need to disclaim — coordinate with tax counsel on how, and whether, she should be involved. Third, remember that a stipulated decision is a decision: once it is entered, there is generally no hopping back for a do-over.
None of this means innocent spouse relief is out of reach. It means the relief has to be protected early, with an eye on the procedural traps, rather than discovered late after the record is already set.
A note for referring counsel
If you have a divorcing or separated client with joint IRS audit, deficiency, or collection issues, the sequence of moves matters enormously, and the window to preserve Section 6015 relief can close quietly. I am always glad to consult with family-law and matrimonial counsel before the tax case reaches a point of no return.
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