Thanks so much for the reply! Really appreciate it!
My parents overstayed because my dad was not doing well in health and diagnsed with Alzheimer after returning to China last time.
-I don't think this chronic illness can stop him to return to US because it is difficult to explain why he can return to US now. If the Dr./hospital prove that he was unable to travel due to the illness, then he needs to apply for SB-1 visa in the US Consulate in Guangzhou to reinstate his green card, but there is not way to do it for your mother's green card. By the way, it is diffcult to get SB-1 visa unless the evidence is very strong. Read these links:
https://travel.state.gov/content/visas/en/immigrate/returning-residents.html
http://guangzhou.usembassy-china.org.cn/sb1_visas_returning_residents.htmm
Do you think if it will help if my parents provide the explanation to the officer at the customs?
-The CBP officer at the port of entry will not care about it. What they do is to deny your entry to US or ask you to go to the immigration court after you enter US.
Thanks a lot!
