Spousal IRAs let stay-at-home spouses contribute the full amount allowed to an individual retirement account in any given year — even if they earn no personal income — as long as their husband or wife earns enough to cover their contribution. Contributions can be made to either a traditional or to a Roth IRA, subject to the usual income caps and contribution limits.
Once spousal IRA money is contributed, it belongs to the non-wage-earning spouse, regardless of where the money came from. The wage-earning spouse need only earn enough income to cover the IRA contribution, as well as any other retirement plan contributions the family makes in a given year.