About Dr. Koob

Dr. Jason Koob is a board-certified emergency physician who has practiced full-time in a community hospital emergency department since 2014, across the full spectrum of emergency care — from chest pain, stroke, and sepsis to trauma resuscitation and airway management. He practices in Northern California and remains in the department every week; his opinions are informed by what emergency medicine actually looks like on shift, not by a recollection of it. He evaluates care against the standard that applied when it was delivered.

His path to expert work is unusual — and deliberate. Before medicine, Dr. Koob worked as an analyst at Cornerstone Research, a litigation consulting firm, supporting expert witnesses and attorneys in complex, high-stakes litigation. He then earned his medical degree at the University of Chicago and completed his emergency medicine residency at Northwestern in downtown Chicago. He came to medicine having already watched expert opinions get built, tested, and taken apart. That order — litigation first, then the emergency department — shapes how he works: precise about what the record shows, responsive to deadlines, and plain about where the evidence runs out.

Dr. Koob accepts engagements from both plaintiff and defense counsel. He approaches every engagement the same way: a rigorous, independent review of the medical record measured against the standard of care, and an honest opinion — including when that opinion doesn't favor the retaining party. The most useful thing an expert offers is clarity: emergency medicine explained in plain language that attorneys, judges, and juries can follow.

Dr. Koob is licensed in California and reviews cases nationwide. His current CV is available below.