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The petitioning U.S. employer may place the H-1B worker on the worksite of another employer if all applicable rules (e.g., Department of Labor rules) are followed. H-1B aliens may work for more than one U.S. employer, but must have a Form I-129 petition approved by each employer."[4] Enforcement of these rules depends upon the employee, however. The Department of Labor has neither the authority nor the manpower to investigate violations of these rules unless and until a complaint is made.