I'm currently on a multi-entry Non O-A Visa, valid until Oct 16, 2020. And so, the typical plan would be to do a border run before this Visa expires, thus getting (most of) the second year.  However, my current US Passport expires June 30, 2021.  Does anyone know what would happen if I did a border run in, say, early October with a passport with (obviously) less than 1-year validity at that point? 

 

Disclaimers:  I understand we are not in normal times as far as border crossings are concerned at the moment; I understand I can endeavor to get a new US passport between now and my current Visa expiration date; I understand the requirements/implications associated with medical insurance coverage under a Non O-A.   

They should stamp you in with untill date to match passport expiry. 

 

When using a visa for entry to the country they will stamp your into the country for the number of days your visa allows. They assume that you would get a new passport before your entry expires.

As already stated, you can only be granted permission of stay for the validity of your Passport.

Assuming your able to make a border run before Oct 16th, you should obtain a new Passport beforehand to take advantage of the full 1 year entry again.