Is it true that it is harder for Officers to volunteer for deployments? If so, how could one increase their chances to deploy?

Agree with the SGM, volunteering to deploy in the AC is hard as a unit may not want to give you up. If you make it known you want to volunteer they may see it as not being loyal to the command. Deploying units are bound to have personnel shortfalls and you might get a chance to go but often they are looking for extra personnel to round out staff for additional missions (LNO duties). It's a gamble unless you know you are going to fill a vacancy in your career field.

MAJ Tom Hutton - If you make it known you want to volunteer they may see it as not being loyal to the command."
Almost guaranteed...even more likely if you have been in the unit any length of time

MAJ Tom Hutton Deploying units are bound to have personnel shortfalls and you might get a chance to go but often they are looking for extra personnel to round out staff for additional missions (LNO duties)."

Again Almost guaranteed.... You are not going to fill a slot others have been filling or covering down on during months of train up .. A deploying unit is tasked to fill many additional non traditional jobs while deployed, and that is just what they get notified of during PDSS, once in country they will find out there need even more.. the higher HQ needs an LT, the unit tasked with base operations will task tenant units for XX personnel, or worse case...... once in that deploying unit , the unit will deploy ONE MORE body that they had planned on leaving back to fill a rear D job, but hey since they have a new body to be the Rear D S-1, why we will take trusty known, LT Bob and leave the new guy back....and whine and cry the new guy will (but I only came here to deploy) to bad, so sad, once you belong to the new unit, that CDR can use you any way they see fit to support the mission.

Well put SGM Erik Marquez!

Agreed. Volunteering for a MOB as a Reservist can be pulling teeth in some branches, and as easy as a phone call in others. In my case, it was the phone call. It also varies by rank: CPT is the easiest Officer rank to get a deployment in, while 1LT and MAJ are a little harder, and 2LT or LTC harder still. The reason is that CPT is the most commonly needed Officer fill in the units that are going -- many units have few LT billets but far more CPT ones, and are slightly hesitant of plugging a LT into a CPT billet, but also there are few senior Officer billets on the deployment and the existing staff of the unit is more likely to be along for the ride (so less need to back-fill). The one thing I'd say is that your branch manager at HRC can often be a great resource to find out which units need additional fill in a shorter timeframe than the year you mention.