Dr. Abaya is Board Certified in Internal Medicine and Nephrology. 

Graduating as Medical Class Valedictorian at the University of the Philippines in 1984, Dr. Abaya began his medical career as an Intern and Resident at Cook County Hospital in Chicago, Illinois. In 1989 Dr. Abaya was honored for his outstanding clinical performance while at Cook County Hospital.

Dr Abaya came to Houston, Texas in 1989 as a Fellow at the Baylor College of Medicine Nephrology Program. He is a Clinical Assistant Professor in Internal Medicine at the University of Texas in the Medical Center.

To better accommodate his patients, Dr. Abaya founded his private practice on Dorrington Street in 2006. 

Dr. Abaya continues to serve his patients at various hospitals and dialysis centers around Houston, but most especially at St. Luke's Episcopal Hospital and at his private practice clinic.