PEOs work equally well in union and non-union workplaces. The National Labor Relations Board (NLRB) recognizes that, in co-employment relationships, worksite employees may be included in the client employer's collective bargaining unit. Where a collective bargaining agreement exists, PEOs fully abide by the agreement's terms. PEOs endorse the rights of employees to organize, or not organize, according to standards of the NLRB.