A Do-Not-Resuscitate (DNR) order is a medical order written by a doctor that instructs healthcare providers not to perform cardiopulmonary resuscitation (CPR) if a patients breathing stops or if their heart stops beating. Ideally, a DNR order is created before an emergency occurs, and it allows patients to choose whether or not they want CPR in an emergency. A DNR order is specific about CPR and does not have instructions for other treatments, such as pain medicine, other medicines, or nutrition. The doctor writes the order only after talking about it with the patient (if possible), the proxy, or the patients family.

A DNR order may be a part of a hospice care plan, where the focus is not to prolong life but to treat symptoms such as pain or shortness of breath and to maintain comfort. If a patient has a DNR order, they always have the right to change their mind and request CPR.

DNR orders are usually written for patients who are terminally ill, suffering from an end-stage condition, or who are in a persistent vegetative state. The DNRO form should be kept in a noticeable, easily accessible place such as the head or foot of a bed, or on the refrigerator, and it should be readily available in the event of an emergency to ensure that the patient’s last wishes will be honored.

It is important to note that a DNR order does not mean "do not treat". Rather, it means only that CPR will not be attempted, and other treatments that may prolong life can still be provided. Depending on the persons condition, these other treatments are usually more likely to be successful than CPR. Treatment that keeps the person free of pain and comfortable (called palliative care) should always be given.

All states provide for special DNR orders that are effective outside of hospitals, wherever the person may be in the community. These are called out-of-hospital DNR orders, Comfort Care orders, No CPR orders, or other terms. Generally, they require the signature of the doctor and patient (or patient’s surrogate), and they provide the patient with a visually distinct quick identification form, bracelet, or necklace that emergency medical services personnel can identify. Many states are now incorporating DNR status into a portable medical order called Physician Orders for Life-Sustaining Treatment (POLST) .