ASHINGTON, April 12 — PacifiCare Health Systems will pay the government $87.3 million to settle accusations that it overcharged for providing benefits to federal employees, the Justice Department said today.

The settlement is the largest of its kind involving government contracts under the Federal Health Benefits Program.

PacifiCare was accused of inflating claims for insurance payments.

Federal prosecutors said the company charged the government at higher rates than its other commercial customers and failed to report rate adjustments that led to significantly higher costs.

The practice, which is illegal, was reported by Valerie Fletcher, a former PacifiCare employee who sued the company in 1998 under the False Claims Act, which allows private parties to sue on behalf of the United States and receive part of the settlement if the government takes the case and recovers money. Ms. Fletcher will receive $3.5 million.

Gregory Scott, executive vice president of PacifiCare, said the company would not be hindered by the payout. "This payment will not be a significant burden and can be met out of the company's operating cash flow," Mr. Scott said.