Chellick was the Jye administrator of Hospital Ship 4-2 on Dinaal. He was brought in to help the Dinaali who were plagued with natural disasters and famine. The Dinaali hired Chellick to run the hospital ship and to make the hard choices of life and death that they didn't want to make. He used an artificial intelligence program called the Allocator to determine who would live and who would die. The more influencial the person, the more care they received, he did this to conserve the limited supply of medicine that was available. Those on Level Red were expendable because their status in society was not high enough. Those on Level Blue received the most including unnecessary treatment, according to their treatment coefficient.
In 2377, he purchased The Doctor and his Mobile emitter from a Dralian trader named Gar. The Doctor was appalled by Chellick's methods. When The Doctor tried to treat the patients on Level Red, Chellick stopped him. He discovered that The Doctor had been taking medicine from the allocator and using it to treat the patients on Level Red. He transferred The Doctor to Level Blue, and interfaced The Doctor's matrix with the allocator so that he could not acquire extra medicine. The Doctor infected Chellick with a virus that had killed a patient named Tebbis who Chellick deemed a low level person. He altered his blood to make the allocator think that Chellick was Tebbis, and the allocator identified him as a person with a low status and denied him treatment. When Chellick's staff refused to help him, in order to save himself, he allowed all Level Red patients to be transferred to Level Blue in order to receive the life saving treatment they needed. (VOY: "Critical Care")