UnitedHealth Group Inc., the largest U.S. health insurer, said its rates for ObamaCare plans in New York may be too low because the failure of a competing insurer last year might lead to shortfalls in payments designed to stabilize Obamacare markets.

In states like New York, health insurers participating in ObamaCare negotiate annually with regulators to set prices for coverage. UnitedHealth’s rates were set anticipating risk-sharing payments designed to stabilize the new insurance markets, William Golden, the company’s northeast region chief executive officer, said Wednesday. If the loss of a participant reduces the funds available to UnitedHealth, the company’s rates in New York’s ObamaCare market may be insufficient, he said.