Jack and Jill went up the hill
to have a lovely wedding
Jack fell down and broke his crown
When Jill learned all his tax debts
That pretty much describes the origin of the taxes faced by an injured spouse: The taxpayer was not married to that spouse at the time he or she incurred the tax obligation or it was assessed or did not sign the tax return where the balance due originated.
In other words, it was never the injured spouse’s debt or obligation in the first place.
What kinds of debts or taxes might the IRS collect (or “offset”) that would affect the injured spouse’s refund?