You can purchase coverage from your travel agent. The Mexican monetary unit is the peso. There is no need to change money before you leave the US and in reality, dollars can be used in most places. Shops and individuals never have change, so large denomination bills are seldom accepted. We recommend carrying as much of your spending money as you feel comfortable in cash and in small bills.
Hotels do little money changing.
Traveler's checks are easy to change only in La Paz . Credit cards are accepted in major hotels, some restaurants and shops. Cash advances can be drawn against credit cards but do not rely on it or expect it to be available. 1 Liter of alcohol is allowed to take home. TIPS are at your discretion.