United HealthCare Services Inc. settled a 1,000-person class action accusing the insurer of improperly denying coverage for prosthetic devices.

The May 23 settlement comes less than a week before the parties were scheduled to go to trial. Details of the settlement will be made public in mid-June, the parties said.

The lawsuit covers United-insured patients whose claims were denied because they sought prosthetic devices more advanced or functional than the minimum available devices. The lawsuit claims United routinely denies coverage...