DH has just informed me, one week to the day before we leave for the US, that his passport expires in 5 months. I've googled and it would appear he's still OK to travel to the US on it, but I'm wondering if someone with more knowledge than me could just confirm that?
I think it's 3 months for the US as that is the period that the visa waiver is for, so it has to cover the maximum period of your visa.
On an associated note, and he probably has, but has he registered on the US Embassy site for visa waiver....this came into force earlier this year, you have to do it online at least 72 hours before you travel, it's then valid for 2 years.
I only point this out because we travel on Friday and I only remembered about it last week!