How do I get my secondary mos added to my erb?

SPC (Join to see) Try talking to S1.

On Active Duty you can only hold one MOS at a time. For you to go back to your old MOS you would have to request the Infantry Proponent to certify that you are fully qualified in your MOS. You can't switch between MOS's or be utilized in the secondary one because you're not considered fully qualified in that MOS any longer. Having a secondary MOS has zero effect on anything at all whatsoever on Active Duty. Adding it to your ERB is strictly a personal preference, secondary MOS's are only utilized in the Reserve Component

When you received your orders assigning the 74D, did it list a secondary of 11B? If not, then you would have to get the orders amended to show the secondary MOS before you will see it on your ERB.