The following list includes a summary of the number of employees an employer must have to be covered by certain federal and Massachusetts employment laws. The list does not include all employment laws. Also, keep in mind that coverage for some laws depends on requirements other than the number of employees. If you are unsure of whether a law applies to your workplace, consult the relevant topic in this book (by clicking on the title) for an explanation of additional requirements.
| Minimum Employees | Law | Application | Topic |
| 1 | Employee Polygraph Protection Act (EPPA) | Very restricted use. | Recruiting and hiring |
| 1 | Fair Labor Standards Act (FLSA) | Applies to "enterprises" with related operations performed for a common business purpose. | Wages and hours |
| 1 | Uniformed Services Employment and Reemployment Rights Act (USERRA) | Applies to all employers regardless of size. | Military leave |
| 1 | Occupational Safety and Health Act (OSH Act) | Applies to all employers engaged in a business affecting commerce. | Safety and health |
| 1 | New Hire Reporting Requirements | Applies to all employers regardless of size. | Recruiting and hiring |
| 1 | Massachusetts Unemployment Compensation Law | Applies to all employers doing business in Massachusetts. | |
| 1 | Massachusetts Workers' Compensation Law | Applies to all employers. | |
| 1 | Family and Medical Leave Act (FMLA) | Applies to public employers. | Family and medical leave |
| 2 | Equal Pay Act (EPA) | No requirements of both Massachusetts and federal statutes. | Wages and hours |
| 2 | Health Insurance Portability and Accountability Act (HIPAA) | Employer is usually not covered unless it operates a healthcare facility. | Health insurance portability and privacy |
| 6 | Massachusetts Anti-Discrimination Law | Applies to public and private employers. | Discrimination |
| 6 | Massachusetts Parental Leave Act | Applies to public and private employers. | Family and medical leave |
| 15 | Title VII of the Civil Rights Act of 1964 (Title VII) | Applies to public and private employers. | Discrimination |
| 15 | Americans with Disabilities Act (ADA) | Applies to private employers. | Disabilities and reasonable accommodations |
| 20 | Age Discrimination in Employment Act (ADEA) | Applies to public and private employers. | Discrimination |
| 20 | Consolidated Omnibus Budget Reconciliation Act (COBRA) | Applies to most employers. | Health insurance continuation coverage |
| 50 | Family and Medical Leave Act (FMLA) | Applies to private employers. | Family and medical leave |
| 50 | Massachusetts Small Necessities Leave Act | Applies to public and private employers. | Family and medical leave |
| 100 | Worker Adjustment and Retraining Notification Act (WARN) | Applies to any private, for-profit and not-for-profit business enterprise. | Plant closings and mass layoffs |