Individual Mobilization Augmentation (IMA) on RallyPoint

Each military service has their own unique requirements for Individual Mobilization Augmentees (IMAs)

An individual reservist attending drills who receives training and is preassigned to an active component organization, a Selective Service System, or a Federal Emergency Management Agency billet that must be filled on, or shortly after, mobilization. Individual mobilization augmentees train on a part-time basis with these organizations to prepare for mobilization. Inactive duty training for individual mobilization augmentees is decided by component policy and can vary from 0 to 48 drills a year.

http://usmilitary.about.com/od/glossarytermsi/g/i3056.htm

US Army IMA information can be found at https://www.hrc.army.mil/STAFF/IMA%20Program%20Overview

US Navy information IA can be found http://www.public.navy.mil/ia/Pages/index.aspx

USAF IMA information can be found at https://afreserve.com/about/reserve-categories

USMC IMA information can be found at http://www.marforres.marines.mil/GeneralSpecialStaff/G1/IMA.aspx