I'm a US citizeng and am going to file I130 and I485 concurrently for my parents who are currently here on B2. Can I file the application the day before their current I94 expires? Do I have to receive a receipt for the application before their current I94 expires? I consulted an attorney and was told I do not need to receive a receipt before I94 expires. I just like to to confirm this here. Thanks!
(I reason I can't file earlier is that we may not get their medical exam results until the day before I94 expires.)