In traditional marriage vows, husband and wife promise to care for each other “in sickness and in health, till death do us part.” But when one or both of the intended spouses are sufficiently sick or disabled, the United States government is the unwelcome wedding guest who offers a reason why these two should not be joined in holy matrimony. One of the cruelest marriage penalties in America’s tax and benefits regime is reserved for the most vulnerable—the poor and disabled.