It all started for Tara Shapiro when her family was driving upstate for her son’s graduation, and her mother-in-law started choking. Dr. Shapiro’s husband jumped in to do the Heimlich maneuver, saving his mother’s life. Which, it turned out, made her furious. “Don’t ever do that to me again,” she told the shaken-up family. She was 81 and had a degenerative muscle disease, and had already decided that she was ready to die.

That night, she and Dr. Shapiro started talking about looking for a doctor who would help her end her life. When her death did come, that summer of 2023, the family could agree it was all very Janice Shapiro. It was on her terms.

The family decided to drive up to Vermont, which had just made medical aid in dying legal for people traveling in from out of state. The Shapiros booked an Airbnb. Just before departing, they invited over a rabbi, but Ms. Shapiro didn’t like him and he was sent away.

Then a priest came, whom she liked much more. They played “My Way,” by Frank Sinatra. Dr. Shapiro recalled mixing the powders in a cup with apple juice, bringing out some sherbet to dull the taste, and handing it to her mother-in-law, who gulped the lethal combination down. Then she told the family that after she died somebody should take the sweatpants she was wearing, which were awfully comfortable.

Within 20 minutes, she was dead. Dr. Shapiro is a palliative care doctor, and she has witnessed hundreds of deaths over her more than 30-year career, but this one turned her inside out. There was, as she expected, the crushing sense of grief. She mourned the person who had been more like a surrogate mother, who treated her like a princess and called incessantly to make sure all was OK after mammograms and who hosted mahjong parties on the deck.

But there were also new questions for Dr. Shapiro. After three decades of working in hospitals, what did it mean to go from fighting off death to speeding it up? What did this mean in terms of the Hippocratic oath, that ancient and often misquoted text meant to guide the profession, with its unsubtle command to “give no deadly medicine”? Dr. Shapiro has been wrestling with these questions. New York has just made legal the practice known as physician-assisted suicide — those in the field prefer the gentler “medical aid in dying,” or MAID.

Since around February, Dr. Shapiro has been working with a group of doctors, nurses, psychologists and other clinicians to create what is believed to be the state’s first practice devoted to helping patients die on their own terms. It opened on Aug. 5, the first day that medical aid in dying was legal in New York. (It doesn’t have an office, because the team will treat patients at their homes.) You can think of it as a start-up for better deaths. They have created a one-stop shop, Quiĕtus, where people can get help meeting every legal and medical requirement for a death on their own terms.

Patients get two medical evaluations and a mental health screening, as well as a prescription for the combination of drugs — sedatives, morphine, lethal doses of cardiac medication — that will kill them. Medical aid in dying is legal in 13 states, and New York has among the strictest regulations, including that patients must be state residents, have six months or less to live, and wait five days between getting the prescription and filling it. As you might imagine, the tasks involved in creating this enterprise, with very few precedents, are complex.

There are questions about insurance, money and liability. There are also questions about whether Quiĕtus is inviting protest from neighbors or criticism by peers. Quiĕtus comprises an eclectic crew of nine clinical professionals.

There is Dr. Shapiro, who radiates suburban ease but whose own life has been punctuated by a pair of deaths — her 2-year-old sister, her 21-year-old nephew — that have made her quietly obsessive about comforting the dying. There is David Atkins, a hospice social worker who used to be a Buddhist...