回複：拿到綠卡之後可以馬上換工作嗎

If you have family based GC, change employer as you wish. If you change your job right after your employment based GC approved, it is assumed that you don't intend to work for current employers infinitely. The attorney told me that it is safe to change employers after one year. Between 6 months to 12 months is a gray area. If you change your job within 6 months, you might get into trouble during the citizenship interview. You might lose your GC if INS officer think your application is a fraud.