Below is an estimated list of the major units deployed within the Multi-National Force - Iraq and other United States military units that were operating in Iraq under the U.S. Central Command (USCENTCOM) in 2009, during the Iraq War.
In military science terminology, the description of the units involved in an operation is known as the order of battle (ORBAT). NATO and the U.S. Department of Defense define the order of battle as the identification, strength, command structure, and disposition of the personnel, units, and equipment of any military force.
From September 2008 to 31 December 2009, the overall military commander in Iraq was General Raymond T. Odierno, Commander, Multi-National Force - Iraq (MNF-I) who reported to United States Central Command. MNF-I replaced Combined Joint Task Force 7 in May 2004. MNF-I consisted of Multi-National Corps - Iraq, Multi-National Security Transition Command - Iraq (MNSTC-I), and the Joint Contracting Command, Iraq/Afghanistan (JCCIA).
On January 1, 2010, Multi-National Force Iraq became United States Forces - Iraq.
There is a distinction in U.S. military terms between the troops of Multinational Force-Iraq and forces which fall directly under CENTCOM's control but are in Iraq also. There are two special operations task forces operating in Iraq, Task Force 77 and CJSOTF-AP. Though TF 77, a 'black' force, does not answer to MNF-Iraq, it is included here for the sake of completeness of the U.S. forces operating within Iraq. TF 77 was under the command of the Joint Special Operations Command and its principal mission was to hunt down the leaders of al-Qaeda in Iraq (AQI).