回复：如果员工换工作后，公司是不是必须要通知移民局终止这个已走员工的Ｈ１Ｂ呢？谢谢

If you don't inform USCIS, you may be liable for future H-1B wages and return travel expenses. As an employer, you may try to minimize your legal exposure. However, in practice, employer may also inform the employee of its intent to file a termination notice to USCIS as a courtesy.