Vermont Gov. Peter Shumlin signed euthanasia legalization into law, making Vermont the fourth state to permit doctors to actively assist in ending lives of patients with consent, reported The Los Angeles Times.

Oregon and Washington underwent a referendum while Montana took on the measure through the courts. The House passed the "Death with Dignity" law last week for Vermont. Patient Choices Vermont, a non-profit advocacy group in the state, has championed the policy and practice since 1997.

"This vote stands as a testament to the power of the citizen voice," Dick Walters, president of Patient Choices, said in a statement last week. "While this bill is popular with the public at large, it is the activism of many bill supporters that reminds us of the powerful impact citizen voices have in Vermont."

The law went into effect on Monday and was co-authored by prominent advocates who also assisted in Oregon's Death with Dignity law.

"This historic legislative victory proves that the aid-in-dying issue is no longer the third rail of politics. In fact, it's a winning issue on which Gov. Shumlin campaigned," said Compassion & Choices President Barbara Coombs Lee, ER and ICU nurse and physician assistant who co-authored Oregon's law. "We congratulate Patient Choices Vermont for its leadership of this multi-year campaign. Their success shows aid in dying has become a legislative winner."

The law allows end-of-life procedures for patients 18 years or older who are diagnosed with an "incurable and irreversible disease" with six months or less to live. Patients would have to request and give consent to doctors to assist with ending their life.

The patient may also withdraw their request and must be notified of end-of-life services, "including palliative care, comfort care, hospice care, and pain control," according to the Vermont bill.

While advocate groups applaud the new measure as a political breakthrough, hospital spokespeople are feeling unprepared given their short timeframe to get ready.

According to a Gallup Poll, 54 percent of medical practitioners and 86 percent of people support euthanasia for terminally ill or those on life support.

Most notable physician, Jack Kevorkian, was a pathologist and physician who assisted in end-of-life care. In 1998, Kevorkian infamously allowed 60 Minutes to live tape the lethal injection of Thomas Youk who was battling Lou Gehrig's disease and had asked Kevorkian for assistance.

Euthanasia is still highly debated worldwide. Aside from the four American states, Switzerland, Belgium, and the Netherlands openly and legally allow end-of-life assistance.