The providers at East Valley Internal Medicine strive to provide compassionate, comprehensive care for all patients. Our well-trained group of providers has a combined 120 years of experience. All provide womens’ and men’s health care. Some have specific areas of expertise.

Mark Walmer, MD

specialties: internal medicine and addiction medicine

Dr. Mark Walmer is board certified in internal medicine. He is the founder of East Valley Internal Medicine and has been practicing since 1984. He specializes in addiction medicine, preventative medicine, hypertension, hypercholesterolemia, and diabetes. Dr. Walmer earned his medical degree from the Medical University of South Carolina in Charleston, South Carolina. He completed his residency at St. Joseph’s Hospital and Medical Center in Phoenix, Arizona. He is the president and medical director of East Valley Internal Medicine.

Armando Rodriguez-Asbun, MD

specialty: Internal Medicine

Dr. Armando Rodriguez-Asbun is board certified in internal medicine and has been practicing since 1996. Dr. Rodriguez-Asbun earned his medical degree from Escuela Nac De Estudios Profls in Tialnepantla, Mexico. He completed an internship and residency at Maricopa Medical Center in Phoenix, Arizona.

Miriam Arce, MD

Dr. Miriam Arce has been practicing since 1965. She earned her medical degree from the Ramon Magsaysay Memorial Medical Center at University of the East in Quezon in the Philippines. She completed her residency at the University of Pennsylvania McKeesport Medical Center in Pittsburg, Pennsylvania.

Boris Schwartz, NP

specialty: pain medicine


Robert Halligan, MD

specialty: addiction medicine


Christina Zimmerman, MSN, NP-C

Christina is a board-certified nurse practitioner and has been practicing medicine sine 2009. She completed her undergraduate studies in nursing and earned her master’s degree at the University of Arizona in Tucson, Arizona.