March 24, 1926 – The hospital was founded, and named Occidental Negros Provincial Hospital (ONPH)
• 25-bed capacity
• Dr. Sixto Y. Orosa Sr. (Author of the landmark Philippine Provincial Hospital-Act) was the first Chief of the Hospital.
• 1937 – 100 bed capacity
In 1941 – War broke out and the Hospital was closed to the Public. The building was used by the Japanese Imperial Forces
February 1945 – After the war, hospital returned to present site.
June 7, 1968 – Name changed to Corazon Locsin Montelibano Memorial Hospital in honor of the lot donor.
1977 – 300 bed capacity
Jan. 21, 1982 – 400 bed capacity w/o corresponding increase in plantilla position until 2013.
July 3, 1984 – Reclassified into regional hospital and renamed CLMMRH.
May 30, 2012 – The National Historical Commission of the Philippines installed the historical marker at the CLMMRH Heritage Building, declaring it a national site.