If I reclassify into a different MOS, how long do have to stay with the new MOS before I can go back to my former MOS?

You have to understand you're at the needs of the Army. If you decide that you're going to reclass, you're costing the Army money. Once you reclass, chances are they're not going to just let you go given they've just invested all of that training time in you. I got the slight hint that you're attempting to reclass to pick up rank and then move back? I'm not saying that's the case, but I've seen that strategy backfire more often than not if that's the idea.

There is no set limit, and you may not be eligible to move back into your old MOS.

Whether you can reclass is based on several factors. You must have at least one year on station before requesting a reclass. Certain MOS require that you hold gave us for a specific amount of time prior to reclass. Your secondary MOS must be more under strength then your new MOS. You must contact the MOS proponent of your secondary MOS and receive a memorandum that states you are still qualified to serve in that MOS.

You're MOS and skill level are currently very understrength. If you are accepted into a new MOS, it will likely be one that is always under strength and you will probably not be able to go back into the Infantry again.

I guess my question is why would you want to reclass only to go back to being Infantry?