+1
From a cell phone holding 0 will give you + which applies the universal international access code.
You would only add the 1 if you were out of the US calling the US.
For example:
US: +1
New Zealand: +64
England: +44
If you are calling from a landline is the US it is 011 then CC but if you are calling abroad it would be 00 then CC. + replaces all of that.