The American Medical Association is asking U.S. antitrust officials to block or modify a recently announced managed care deal.
If officials let UnitedHealth Group Inc., Minnetonka, Minn., complete the recently announced acquisition of Sierra Health Services Inc., Las Vegas, as planned, UnitedHealth will end up with 95% of the Las Vegas-Paradise metropolitan area health maintenance organization market and 78% of the Nevada HMO market, according to the AMA, Chicago.