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

UnitedHealth Group is offering a voluntary separation package to thousands of employees, anonymous workers are posting on social media and layoff forums. | UnitedHealth Group is rolling out a voluntary separation package to its employees.

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