The legal doctrine of sovereign immunity limits the circumstances under which a private person or entity (a nongovernmental unit) may sue a state government or the federal government. Sovereign immunity in the United States was derived from the English common law policy (from Great Britain) that the king (the sovereign) could do no wrong and should not be held to account by his subjects (the people).

Current legal theory also relies on sovereign immunity to protect the public treasury (the fisc) from unlimited claims.

Many states have laws (statutes) known as tort claims acts that waive the government’s immunity in whole or in part for certain specified claims and allow private parties (persons or entities) to sue the government for torts (wrongful acts) committed by persons acting on behalf of the government. In some instances, tort claims acts waive sovereign immunity for claims against the government for personal injuries (as well as for property damage).

And the U.S. Congress has passed a law (a statute) known as the Federal Tort Claims Act that waives the federal government’s immunity for certain claims and allows private parties (persons or entities) to sue the federal government for torts (wrongful acts) committed by persons acting on behalf of the federal government. The Federal Tort Claims Act is located in the United States Code, beginning at 28 U.S.C. §2674.

Lawsuits against the federal government under the Federal Tort Claims Act must be filed in federal courts in the United States.

In Colorado, the legal doctrine of sovereign immunity, which originates from English common law, generally prevents the state government from being sued without its consent. However, Colorado, like many other states, has enacted a tort claims act known as the Colorado Governmental Immunity Act (CGIA). This act waives the state's sovereign immunity in certain instances, allowing individuals to sue the state for wrongful acts committed by government employees or agents under specific circumstances. The CGIA outlines the types of claims that can be brought against the state, the notice requirements that claimants must follow, and the limitations on damages that can be awarded. At the federal level, the Federal Tort Claims Act (FTCA) similarly waives sovereign immunity for certain types of tort claims against the United States government. Under the FTCA, private parties can bring claims for wrongful acts committed by federal employees in their official capacity, but these claims must be filed in federal court. Both the CGIA and the FTCA have specific procedures and limitations that must be adhered to when pursuing claims against the government.