What is I&I duty in the USMC and how do you get it?

Easiest way to explain... Reserve units needs to be staffed throughout the month to keep up with operations, funeral duties, Toys for Tots, and other obligations. The Marines that staff are made up of active and active reserve Marines. Sometimes there are also reserve Marines on active duty orders for a period of time. It can be a fun duty, but it is very demanding and one should be well rounded in their MOS as you are very limited to personnel. At certain units you could possibly be the only one so it is very important to have MOS credibility. Its a duty you can request through your MOS monitor but usually on a PCS move.

I&I = Inspector & Instructor. These are the active duty Marines who are there to augment Reserve training and keep the unit moving between drill periods. As far as I know, it is a volunteer billet. Mostly admin and supply billets. All the I&I staff I dealt with had very little interaction with the "common" reservist. On the officer side you will find your S or G shops with a few I&I officers.

Instructor - Inspector.with a USMCR unit. A friend, Marine Artillery, no CAR Ribbon, just left a I & I post in an Anglico unit to attend a school.@PFC Tony Wallace