What department in an organization is responsible for ACA? Benefits? Finance? Payroll? HR?

Because the data that is required to comply with regulations under the Affordable Care Act is found in multiple departments in large organizations, all departments must combine efforts to address ACA compliance.  Together the benefits, finance, payroll and HR departments must first produce the required data, then ensure that compliance rules are followed.  It is not uncommon for companies to assign ultimate responsibility for ACA to the chief finance officer or to the human resource director, and some companies assign ACA compliance to the benefits director.