On November 15, 1946, Trygve Erickson is born at St. Luke's Hospital on Seattle's Capitol Hill and Group Health announces him to be the first baby born under Group Health ownership of the hospital (which is later renamed Group Health Hospital). Group Health Cooperative is not quite two years old and is in the process of purchasing the hospital from the Medical Security Clinic.
But Group Health did not formally take over the hospital until January 1, 1947, so it might be said that the first baby born under Group Health ownership of the hospital was Roger Paulson, born on January 15, 1947.