William Miller, MD, MBA
Chief Executive Officer
As a practicing physician, Dr. Miller sees and treats patients with allergies every day. He joined Allergy Services of America as Chief Executive Officer in 2025. Dr. Miller combines his clinical and administrative backgrounds to prioritize creating an excellent clinical program while also supporting providers and their staff. He understands the challenges that modern medical practices are facing because he has lived them. Dr. Miller ensures that ASA is providing a world-class clinical allergy program while also developing trust and transparency with each of our partners.
Ryan Sullivan, MD
Medical Director - Clinical Allergy Services
• Dr. Sullivan serves as the Medical Director for ASA's Clinical Allergy Services, overseeing the program and its management across each of our partner facilities. Dr. Sullivan approves all allergy protocols, and he is responsible for ensuring that ASA abides by all national guidelines, as well as ABAI, ACAAI and AAAAI standards
• Fellowship in Allergy, Asthma and Immunology at the University of Kansas
• Board certified by the American Board of Internal Medicine as well as the American Board of Allergy and Immunology (ABAI)
• Member of the American Academy of Allergy, Asthma, and Immunology (AAAAI) and of the American College of Allergy, Asthma, and Immunology (ACAAI)
Abdul Ibrahim
Executive Vice President
• 30+ years of professional experience in the diagnosis and treatment of allergies and asthma
• More than 10 years of clinical trials and study research in the areas of allergy, asthma and immune related diseases
• Internationally published author in the fields of allergy and immunology
• Dr. Ibrahim oversees our Clinical Allergy Coordinators, as well as operations across each of our partner facilities