Dr. Katz studies amyotrophic lateral sclerosis (ALS), myasthenia gravis, neuromuscular diseases, pain management, peripheral neuropathy, poliomyelitis, radiculopathies, and spinal muscular atrophy.

He leads clinical trials of pharmacotherapies to slow the progression of ALS; device trials; a study of the NeuRX Diaphragm Pacing System to support patients with diaphragm weakness; and observational studies of factors affecting disease progression. 

Dr. Katz and others at the Forbes Norris Center work with researchers at the University of California, San Diego, to study mutations in RNA binding proteins that cause neuronal dysfunction and death. In 2014, Dr. Katz and colleagues at CPMC collaborated with Cedars-Sinai Regenerative Medicine Institute on new stem cell and gene therapy techniques to treat ALS patients.

He is President of the ALS Research Group—an international ALS research collaboration. He sits on the medical advisory board for GBS-CIDP Foundation International and the Myasthenia Gravis Association.