Sovereign immunity (also known as governmental immunity) in American law was derived from the British common law doctrine that the King could do no wrong—and thus could not be sued. Sovereign immunity varies from state to state, but typically applies to state governments as well as the federal government.

For example, sovereign immunity protects the state and its various provisions of state government—including agencies, boards, hospitals, and universities—from liability and from suit—unless the immunity has been waived. Similarly, sovereign immunity protects political subdivisions—including counties, cities, and school districts—from liability and from suit—unless the immunity has been waived.

Thus, sovereign immunity encompasses two principles: (1) immunity from suit and (2) immunity from liability. Immunity from suit bars a suit against the state or other governmental entity unless the Legislature expressly gives consent. Immunity from liability protects the state or other governmental entity from judgments even if the Legislature has expressly given consent to sue.

In some states, when a governmental entity contracts, it is liable on contracts made for its benefit as if it were a private person. Consequently, when a governmental entity contracts with private citizens it waives immunity from liability. But the governmental entity does not waive immunity from suit simply by contracting with a private person. Legislative consent to sue is still necessary.

But federal and state governments (generally the U.S. Congress and state legislatures) have the ability to waive their sovereign immunity. Waivers of sovereign immunity are usually included in state and federal statutes and interpreted and applied by state and federal courts in court opinions.

A party may establish legislative consent by referencing a statute or a resolution granting express legislative permission. Legislative consent to sue the state or other governmental entity must be expressed in clear and unambiguous language.

In Massachusetts, sovereign immunity is a legal doctrine that protects the state government, its agencies, and political subdivisions from being sued or held liable in court without its consent. This immunity extends to various state entities, including boards, hospitals, and universities, as well as counties, cities, and school districts. Sovereign immunity in Massachusetts is based on two principles: immunity from suit, which prevents lawsuits against the state unless there is express legislative consent, and immunity from liability, which shields the state from judgments even if consent to sue has been granted. However, the state can waive this immunity through legislation, and it has done so in certain instances. For example, when the state enters into contracts, it may be liable as a private party would be, but this does not automatically waive its immunity from being sued. Clear and unambiguous language in a statute or resolution is required to establish legislative consent for a lawsuit against the state or its entities. Waivers of sovereign immunity are often found in state statutes and are interpreted by the courts.