The USAF has some of the most capable aircraft in the world within its fleet. Many of the aircraft that it fields in any conflict are older and were designed decades ago; but it also has some very capable next generation aircraft like the F-22 and the F-35 that will be coming online in the next few years.
The F-22 and the F-35 are similar in that they are both fighter aircraft that are designed from the outset to have stealth characteristics to make them harder to see by enemy radar. With the F-35 being the newer aircraft, it has more advanced radar-absorbing coatings on the surface than the F-22. Lockheed has announced that it is now integrating some of the more advanced coatings the F-35 uses onto the F-22 fighters coming of the assembly line.
"Some of the [low observables] coatings system and gap-fillers that the F-35 had an advantage on, we have incorporated into the Raptor," said Jeff Babione, vice president and general 
Defense News reports that Babione claims that the new coatings don’t change the radar cross section of the F-22. The coatings according to Babione are simply to reduce maintenance costs. He said, "[The F-35 program] had some more robust materials that were more durable and we were able to pull those back on to the F-22. So our system is better, and the life-cycle cost of the F-22 is reduced."
Analyst Dan Goure said, "It's not going to transform the airplane, but what it's going to really do is make it much cheaper to operate the F-22 fleet, which is terribly important given its small size."
However, some doubt that the new coatings won't improve the radar visibility of the F-22. Goure also noted, "I would be very surprised if this wasn't an improvement in stealth characteristics."
Lockheed had to make some changes to the coatings to be used on the F-22 that the F-35 didn’t require. Goure said, "It's [the F-22] operating at a higher altitude typically and [at] faster speeds, and that would put different stresses on the material."
The only F-22 fighters that are using the new coating for now are the most recent Lot 9 aircraft and other new and improved materials are still in the final qualification phase. Lockheed hopes to roll the coatings out to the entire fleet next year. At that point, all existing aircraft will be retrofitted with the new coating.
The F-22 was recently left out of the fighting in Libya because it was both too advanced and too limited at the same time.
* NATO forces have a total of about 195 aircraft at their disposal.