The Rights of the Terminally Ill bill passed on a conscience vote in the Northern Territory parliament late on Thursday, with the gag intact.
The territory became the first Australian jurisdiction to make voluntary euthanasia legal in 1995, but the laws were overturned in 1997 by the federal government under John Howard.
All six states and the ACT have since passed their own laws allowing it.
The federal veto was only lifted in 2022, restoring the NT's right to make its own assisted dying laws.
The NT bill requires that only people predicted by doctors to have 12 months or less to live would have access to assisted dying.
In the NT parliament on Thursday government backbencher Tanzil Rahman spoke against the gag clause that would bar healthcare professionals from initiating conversations about end-of-life options with patients.
Elderly patients could be bedridden and dying in an aged-care home in a one-clinic town and it would not be compassionate to prevent them talking to a doctor about end-of -life options, he told parliament on Thursday.
"If the facility says no, that's it," ," Mr Rahman said.
"This cannot be a bill for the rights of the terminally ill if we restrict conversations in these premises."
Opposition Leader Selina Uibo also argued against residents of aged care institutions being denied information, saying they must be allowed to make informed choices about end-of-life options.
"It is a dangerous slope when politicians start to tell the medical profession what they can and cannot offer a patient," Ms Uibo said.
NT Attorney-General Marie-Clare Boothby defended the gag on doctors, saying it was to safeguard terminally ill and often vulnerable people from being coerced into ending their lives.
"This safeguard is not to protect the doctor but to protect the patient," she said under detailed questioning.
The point was to provide safeguards to ensure end-of-life decisions were patient-led and "genuinely voluntary".
But other MPs questioned whether the gag clause was legally enforceable.
Government MP Brian O'Gallagher said he considered the clause was an overreach, "trying to use a sledgehammer to knock over one very isolated nut ... it just doesn't seem right to me".
Independent MP Justine Davis said putting a gag order on doctors was "tantamount to censorship".
Australian Medical Association NT President John Zorbas said earlier in the week the gag clause undermined the doctor-patient relationship.
"Legislating what a doctor can and cannot discuss when a patient is facing the end of their life is an unacceptable intrusion into clinical practice," he said.
Despite the opposition to the gag clause, moves to remove it from the bill were defeated on the floor of the house on Thursday evening.
Only South Australia has a similar gag on doctors.
Bids to quash the 12-month medical prognosis provision on the basis it involved unreliable predictions by doctors and was unworkable were also defeated.
NT Health would have 18 months to introduce the program and a three-year review would be carried out.
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