UnitedHealthcare will resort to laying off staff if a certain number of people do not accept the buyouts, sources told CNBC.

UnitedHealth's insurance unit is offering employees in its benefits operations unit the option to accept buyouts if they quit by March 3.

In a statement to ABC News, a company spokesperson said the "voluntary option is part of our ongoing efforts to ensure our team is best positioned to meet the evolving needs of the people and customers we are honored to serve.