Short Answer: Not required by federal law, but some states mandate them.
Full Answer: The Fair Labor Standards Act (FLSA) does not require employers to provide breaks or meal periods. However, employers must be paid if they offer short breaks (5 to 20 minutes). Meal periods, typically 30 minutes or longer, can be unpaid if the employee is completely relieved of duties. Some states, like California and New York, have specific laws mandating breaks and meal periods based on hours worked. Check your state labor laws for requirements.
General Federal Standard: Breaks are optional under FLSA but must be paid if offered; meal periods can be unpaid if free of duties.
Link to a legislative resource from trusted sources: U.S. Department of Labor - Breaks and Meal Periods