Due to the unpredictable nature of project-based research funding, length of employment for NPC employees and the employee/employer relationship should be unspecified, with no time commitments made or implied.  Accordingly, all applicants for employment should complete an employment disclaimer form (otherwise known as an “at will” statement). The purpose of the disclaimer is to inform the applicant that their employment will be “at will," is not for any specific duration, and may be terminated at any time without cause, and with or without advance notice. A disclaimer form can help avert claims of wrongful discharge. 

Continued employment of all NPC employees should be conditional upon many factors, including performance and availability of appropriate work and funds. Any oral or written statements or promises to the contrary by a PI, supervisor, director, or employee of the NPC are not binding upon the NPC, unless it is confirmed in writing and signed by the executive director. The provision of benefits does not constitute a promise of employment. The Employment Request Form or hire letter does not constitute an exception to the "at will" policy.  An "at will" policy should be included in your employee handbook and reiterated regularly in interactions with employees. 

The “at will” policy does have exceptions and legal limitations. Although employers may terminate “at will” employees at any time, they cannot fire employees for an illegal or discriminatory reason such as race, creed, sex, color, national origin, religion, age, marital status, physical or mental disability, union activity, sexual orientation, pregnancy, medical condition, parental status, or military status.

Also, some states have "at will" statutes and regulations.  Know your state rules!