Federal and state labor laws do not require an employee to be on time for work. However, an employer is not obligated to pay an employee for time he is not at work and in most cases can terminate an employee for being late.
Wage and Hour Issues
The Fair Labor Standards Act (FLSA) and most state laws require that employees be paid for all hours worked. Therefore, if an employee is late it is appropriate for an employer not to pay her for the minutes or hours that were missed. However, employers can't fine or deduct wages from an employee as a punishment for being late.
Most states are considered "right to work" or "at-will" employment states. Therefore, it is at the employers' or employees' discretion to terminate the employment at any time with or without cause. An employer is allowed to set policies that force employees to be on time for work or face disciplinary procedures up to and including termination.
If an employee is in a union, there is usually a procedure regarding tardiness outlined in the collective bargaining agreement. For example, a collective bargaining agreement may indicate that on the first occasion of tardiness the employee receives a verbal warning, followed by a written warning and finally termination. If procedures are outlined in the collective bargaining agreement, it is imperative that the employer abide by the terms, as it is a legal contract.