There are no laws that require employers to keep personnel files on each employee. However, since there are specific employee records, such as W-4 (W-four) and I-9 (eye-nine) forms, that must be retained under federal laws, many companies use personnel files as a convenient means to keep track of these documents and other important employee data. In general, if employers choose to keep personnel files, all information collected and retained about employees should be strictly job-related. This information can include addresses, social security numbers, resumes, job titles, performance evaluations, and payroll records. Some laws may dictate that certain information like medical records and immigration data be kept in a separate place to protect confidentiality. Since employees have a right to expect that their private information will not be disclosed except when it's warranted, responsible employers should keep personnel files in a secure place as well as limit access to them. Employers, however, should be aware that some states allow employees to have access to information used by employers that determine their qualifications for employment, promotion, and additional compensation, as well as information about discipline and terminations. Information that's found to be inaccurate or not up-to-date should be corrected. Employers should also note that releasing deeply personal information, such as the results of a drug test, or false information about an employee to coworkers or the public is a clear violation of privacy. Employers who choose to do so can be found guilty of defamation in a court of law.