29 C.F.R. § 103.40 – Joint Employers.

(a) An employer, as defined by Section 2(2) of the National Labor Relations Act (the Act), may be considered a joint employer of a separate employer's employees only if the two employers share or codetermine the employees' essential terms and conditions of employment. To establish that an entity shares or codetermines the essential terms and conditions of another employer's employees, the entity must possess and exercise such substantial direct and immediate control over one or more essential terms or conditions of their employment as would warrant finding that the entity meaningfully affects matters relating to the employment relationship with those employees. Evidence of the entity's indirect control over essential terms and conditions of employment of another employer's employees, the entity's contractually reserved but never exercised authority over the essential terms and conditions of employment of another employer's employees, or the entity's control over mandatory subjects of bargaining other than the essential terms and conditions of employment is probative of joint-employer status, but only to the extent it supplements and reinforces evidence of the entity's possession or exercise of direct and immediate control over a particular essential term and condition of employment. Joint-employer status must be determined on the totality of the relevant facts in each particular employment setting. The party asserting that an entity is a joint employer has the burden of proof.
(b) “Essential terms and conditions of employment” means wages, benefits, hours of work, hiring, discharge, discipline, supervision, and direction.
(c) “Direct and Immediate Control” means the following with respect to each respective essential employment term or condition:
1. (1) Wages. An entity exercises direct and immediate control over wages if it actually determines the wage rates, salary or other rate of pay that is paid to another employer's individual employees or job classifications. An entity does not exercise direct and immediate control over wages by entering into a cost-plus contract (with or without a maximum reimbursable wage rate).
2. (2) Benefits. An entity exercises direct and immediate control over benefits if it actually determines the fringe benefits to be provided or offered to another employer's employees. This would include selecting the benefit plans (such as health insurance plans and pension plans) and/or level of benefits provided to another employer's employees. An entity does not exercise direct and immediate control over benefits by permitting another employer, under an arm's-length contract, to participate in its benefit plans.
3. (3) Hours of work. An entity exercises direct and immediate control over hours of work if it actually determines work schedules or the work hours, including overtime, of another employer's employees. An entity does not exercise direct and immediate control over hours of work by establishing an enterprise's operating hours or when it needs the services provided by another employer.
4. (4) Hiring. An entity exercises direct and immediate control over hiring if it actually determines which particular employees will be hired and which employees will not. An entity does not exercise direct and immediate control over hiring by requesting changes in staffing levels to accomplish tasks or by setting minimal hiring standards such as those required by government regulation.
5. (5) Discharge. An entity exercises direct and immediate control over discharge if it actually decides to terminate the employment of another employer's employee. An entity does not exercise direct and immediate control over discharge by bringing misconduct or poor performance to the attention of another employer that makes the actual discharge decision, by expressing a negative opinion of another employer's employee, by refusing to allow another employer's employee to continue performing work under a contract, or by setting minimal standards of performance or conduct, such as those required by government regulation.
6. (6) Discipline. An entity exercises direct and immediate control over discipline if it actually decides to suspend or otherwise discipline another employer's employee. An entity does not exercise direct and immediate control over discipline by bringing misconduct or poor performance to the attention of another employer that makes the actual disciplinary decision, by expressing a negative opinion of another employer's employee, or by refusing to allow another employer's employee to access its premises or perform work under a contract.
7. (7) Supervision. An entity exercises direct and immediate control over supervision by actually instructing another employer's employees how to perform their work or by actually issuing employee performance appraisals. An entity does not exercise direct and immediate control over supervision when its instructions are limited and routine and consist primarily of telling another employer's employees what work to perform, or where and when to perform the work, but not how to perform it.
8. (8) Direction. An entity exercises direct and immediate control over direction by assigning particular employees their individual work schedules, positions, and tasks. An entity does not exercise direct and immediate control over direction by setting schedules for completion of a project or by describing the work to be accomplished on a project.
(d) “Substantial direct and immediate control” means direct and immediate control that has a regular or continuous consequential effect on an essential term or condition of employment of another employer's employees. Such control is not “substantial” if only exercised on a sporadic, isolated, or de minimis basis.
(e) “Indirect control” means indirect control over essential terms and conditions of employment of another employer's employees but not control or influence over setting the objectives, basic ground rules, or expectations for another entity's performance under a contract.
(f) “Contractually reserved authority over essential terms and conditions of employment” means the authority that an entity reserves to itself, under the terms of a contract with another employer, over the essential terms and conditions of employment of that other employer's employees, but that has never been exercised.