In Maryland, as in most states, a person can sue his or her spouse. Spouses can sue one another for anything for which non-spouses can sue one another. This includes a lawsuit for breach of contract or a tort action. The defense of interspousal immunity is no longer available.
Read the Case: Bozman v. Bozman, 376 Md. 461 (2003)
Maryland's History - In the past, Maryland used to limit the ability of a person to sue his or her spouse. The common law (case law) rule prohibiting one spouse from suing his/her spouse was called interspousal immunity. The interspousal immunity rule was based on court holdings that by marriage, a husband and wife become one person in law.
Blackstone's Commentaries gave the doctrine's rationale:
"By marriage, the husband and wife are one person in law: that is, the very being or legal existence of the woman is suspended during the marriage, or at least is incorporated and consolidated into that of the husband: under whose wing, protection, and cover, she performs everything; and is therefore called in our law-french a feme-covert, foemina viro co-operta; is said to be covert-baron, or under the protection and influence of her husband, her baron, or lord; and her condition during her marriage is called her coverture. Upon this principle, of a union of person in husband and wife, depend almost all the legal rights, duties, and disabilities, that either of them acquire by the marriage." He adds, in discussing the consequences of this union of husband and wife, "If the wife be injured in her person or her property, she can bring no action for redress without her husband's concurrence, and in his name, as well as her own: neither can she be sued without making the husband a defendant." Quoted in the Bozman case, at page 469.