I'm planning on travelling to EPC for the first time in January, and my passport expires in May. According to the State Department website, my passport just needs to be valid at the time of entry, but I've read elsewhere that it needs to be valid for at least 6 months beyond the point of entry. Can anybody who's been recently comment on any issues they've had going into Mexico?
Check Mexico's rules. It's the other country that will have rules about how close to expiration you can travel.
Edit: Google says Mexico has a 6 month rule for passports. It needs to be good for 6 months from entry because that's the maximum amount of time you can stay in the country on a single visa. I'd guess that there's some discretion there for the border officials, but I wouldn't count on being allowed in.