Is AIM-120D in service

As of December 2010, the answer is "no."

"Jane's Defence Weekly

December 01, 2010 issue

China's SD-10 claimed to be a dual-mode AAM.

Robert Hewson Jane's Air-Launched Weapons Editor - Zhuhai, China

China's SD-10 medium-range air-to-air missile (AAM), as exhibited at Airshow China earlier in November, may be a considerably more capable weapon than was hitherto believed, Jane's understands.

Officials from the SD-10's manufacturer, the Luoyang Electro-Optical Technology Development Center (LOEC), said the missile was designed from the beginning to function with a dual-mode seeker operating in distinct active and passive radar homing modes. If so, the SD-10 is the first AAM to enter service with this acknowledged capability.

There have been suggestions that the latest AIM-120D Advanced Medium-Range Air-to-Air Missile (AMRAAM) developed by Raytheon for the US Air Force and Navy has a similar dual-mode seeker capability. The full capabilities of the AIM-120D remain classified, but its development has been problematic and it has yet to enter operational service."