USI Insurance Services , a local and national insurance brokerage and consulting firm headquartered in Valhalla, N.Y., has hired Christopher Callahan as vice president of the employee benefits practice for the Warwick, R.I., office. In his role at USI, Callahan will help clients develop competitive and cost effective benefit programs, including group medical, dental, life, disability, voluntary and wellness initiatives, for both fully-insured and self-funded arrangements.