Whole-home. Poking around in the thermostat menu found me a "Recirc" option for the fan, which suggested to me that the other options are not all-recirculated.

From what I've read, many systems use a mix of fresh and recirculated air unless you set it to 100% recirculated. But I guess that may vary depending on the age of the system (and I don't know when exactly mine dates from, other than sometime between 1985 and 2003).