Four states, including Kansas, Montana, Idaho, Utah, do not allow the insanity defense. In other states, the standards for proving this defense vary widely. The following provides the status of the insanity defense in each jurisdiction.
| ALABAMA | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| ALASKA | The state uses a modified version of the M'Naghten Rule. The burden of proof is on the defendant. A guilty but mentally ill verdict is allowed. |
| ARIZONA | The state uses a modified version of the M'Naghten Rule. The burden of proof is on the defendant. A guilty but insane verdict is allowed. |
| ARKANSAS | The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant. |
| CALIFORNIA | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| COLORADO | The state uses a modified version of the M'Naghten Rule with the Irresistible Impulse Test. The burden of proof is on the state. |
| CONNECTICUT | The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant. |
| DELAWARE | The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant. |
| DISTRICT OF COLUMBIA | The state uses the Model Penal Code rule. The burden of proof is on the defendant. |
| FLORIDA | The state uses the M'Naghten Rule. The burden of proof is on the state. |
| GEORGIA | The state uses a modified version of the M'Naghten Rule. The burden of proof is on the defendant. A guilty but mentally ill verdict is allowed. |
| HAWAII | The state uses the Model Penal Code rule. The burden of proof is on the defendant. |
| IDAHO | The state has abolished the insanity defense. The state allows a guilty but insane verdict. |
| ILLINOIS | The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant. |
| INDIANA | The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant. |
| IOWA | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| KANSAS | The state has abolished the insanity defense. |
| KENTUCKY | The state uses the Model Penal Code rule. The burden of proof is on the defendant. |
| LOUISIANA | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| MAINE | The state uses a modified version of the Model Penal Code rule. The burden of proof is on the defendant. |
| MARYLAND | The state uses the Model Penal Code rule. The burden of proof is on the defendant. |
| MASSACHUSETTS | The state uses the Model Penal Code rule. The burden of proof is on the state. |
| MICHIGAN | The state uses the Model Penal Code rule. The burden of proof is on the state. |
| MINNESOTA | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| MISSISSIPPI | The state uses the M'Naghten Rule. The burden of proof is on the state. An acquitted by reason of insanity verdict is allowed. |
| MISSOURI | The state uses a modified version of the M'Naghten Rule. The burden of proof is on the defendant. |
| MONTANA | The state has abolished the insanity defense, although a guilty but insane verdict is allowed. |
| NEBRASKA | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| NEVADA | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| NEW HAMPSHIRE | The state uses the Durham standard. The burden of proof is on the defendant. |
| NEW JERSEY | The state uses the M'Naghten Rule. The burden of proof is on the state. |
| NEW MEXICO | The state uses the M'Naghten Rule with the Irresistible Impulse Test. The burden of proof is on the state. |
| NEW YORK | The state uses the Model Penal Code rule. The burden of proof is on the defendant. |
| NORTH CAROLINA | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| NORTH DAKOTA | The state uses the Model Penal Code rule. The burden of proof is on the state. |
| OHIO | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| OKLAHOMA | The state uses the M'Naghten Rule. The burden of proof is on the state. |
| OREGON | The state uses the Model Penal Code rule. The burden of proof is on the defendant. |
| PENNSYLVANIA | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| RHODE ISLAND | The state uses the Model Penal Code rule. The burden of proof is on the defendant. |
| SOUTH CAROLINA | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| SOUTH DAKOTA | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| TENNESSEE | The state uses the Model Penal Code rule. The burden of proof is on the state. |
| TEXAS | The state uses the M'Naghten Rule with the Irresistible Impulse Test. The burden of proof is on the defendant. |
| UTAH | The state has abolished the insanity defense, but guilty but mentally ill verdicts are allowed. |
| VERMONT | The state uses the Model Penal Code rule. The burden of proof is on the defendant. |
| VIRGINIA | The state uses the M'Naghten Rule with the Irresistible Impulse Test. The burden of proof is on the defendant. |
| WASHINGTON | The state uses the M'Naghten Rule. The burden of proof is on the defendant. |
| WEST VIRGINIA | The state uses the Model Penal Code rule. The burden of proof is on the state. |
| WISCONSIN | The state uses the Model Penal Code rule. The burden of proof is on the defendant. |
| WYOMING | The state uses the Model Penal Code rule. The burden of proof is on the defendant. |
