If you have a monthly or annual NAVIGO pass covering Zones 1-2 (metro/bus/tram and RERs in Paris and immediate suburbs), you can use it in any zone during the school holidays, July 14- August 16, including both Paris airports (RER and RoissyBus or OrlyBus, but not OrlyVal), Versailles and Disneyland.
And beginning September 1st, 2015, the monthly and annual Navigo passes will be zone-free all year long. It’s a great deal and simplifies life for those who make frequent trips out of the city center.
For more info check out the rates on the RATP website.