1 to 14 Employees:
Civil Rights Act 1964 and Civil Rights Act 1991, Title VII (for employment agencies and labor organizations). See 15-19 for other employers.
Consumer Credit Protection Act of 1968
Employee Polygraph Protection Act (1988)
Employee Retirement Income Security Act (ERISA) 1974 (if company offers benefits)
Equal Pay Act of 1963
Fair Credit Reporting Act (1970)
Fair Labor Standards Act (FLSA) (1938 * Amended 2004)
Federal Insurance Contributions Act of 1935 (FICA) (Social Security)
Health Insurance Portability and Accountability Act (HIPAA) of 1996 (if company offers benefits)
Immigration Reform & Control Act (IRCA) (1986)
Labor-Management Relations Act (Taft-Hartley) 1947
National Labor Relations Act (NLRA) 1935
Occupational Safety and Health Act (1970)
Uniform Guidelines of Employee Selection Procedures (1978)
Uniformed Services Employment & Re-employment Rights Act of 1994

11-14 Employees, add
Occupational Safety & Health Act (OSHA) (1970) (maintain record of job related injuries and illnesses)

15-19 Employees, add
Civil Rights Act of 1964 Title VII, Civil Rights Act of 1991
Title I, Americans with Disabilities Act of 1990, (ADA)

20-49 Employees, add
Age Discrimination in Employment Act (1967) (ADEA)
Consolidated Omnibus Budget Reconciliation Act of 1985 (COBRA)

50 or more Employees, add
Family and Medical Leave Act of 1993 (FMLA)
EEO-1 Report filed annually w/EEOC if organization is a federal contractor

100 or more Employees, add
Worker Adjustment & Retraining Notification Act of 1988 (WARN)
EEO-1 Report filed annually w/EEOC if organization is not a federal contractor

Federal Contractors, add
Executive Orders 11246 (1965), 11375 (1967), 11478 (1969); Vocational Rehabilitation Act of 1973; Drug Free Workplace Act of 1988; Vietnam-Era Veterans Readjustment Act of 1974; Davis Bacon Act of 1931; Copeland Act of 1934; Walsh-Healy Act of 1936 . Service Contract Act (1965)

Source: Society for Human Resource Management