Patient Portal; John Okerblom, MD. Home » Physicians » John Okerblom, MD. Dr. Okerblom is Board Certified in Family Practice. Dr. John Okerblom has been in practice in Santa Maria since 1982, having served as Chief of Staff at Marian Medical Center. He graduated Summa Cum Laude from Occidental College, was elected into the Alpha Omega Alpha ....