The Fair Labor Standards Act (FLSA) does not define full time employee or part time employee. What is counted as a full time employee is generally defined by the employer by policy. The definition of a full time employee is often published in the employee handbook.
A full time employee has traditionally worked a 40 hour work week with the expectation that exempt employees will work the hours necessary to accomplish their jobs. Non-exempt employees must be paid overtime for time worked in excess of 40 hours. Today, some employers count employees as full time if they work 30, 32, or 36 hours a week. In fact, fewer required work hours is considered a non-standard benefit in some organizations.
In many organizations, one differentiation between full time and part time employees is eligibility for benefits such as health insurance, paid time off (PTO), paid vacation days, and sick leave. Some organizations enable part time employees to collect a pro-rated set of benefits. In other organizations, part time status makes an employee ineligible for any benefits.