I know rules can vary from prison to prison,and state to state, so what I share is just a guideline.  Most times a letter sent to a prison can be traced to an inmate, since he is still in the system.  If he is moved, the prison should easily be able to forward the letter.  

What also may factor is the custody level of the inmate, the lower the security, the better his chance to contact you.  On a general level, any inmate ought to be able to send a letter, but that is with excpetions.

When you are concerned about his local, the first step is to simply call the prison and ask for his location.  You don't need to get too technical, just find out if he has been moved and where.  Once you know one way or the other, give him time to contact you.  If he is still at the current prison, he is likely waiting to be moved, but if he has already been moved, it is possible he might be trying to adjust.  Going from one prison to another can be tough, when everything is new to an inmate.  If he has already been moved, send him a quick letter just to let him know that you know where he is, so he may be able to rest a bit easier.  Remember, he is just as concerned about getting in touch with you as you are with him.

Above all things, stay patient and be calm.  Hang in there, ok?

the way i find out when my husband got transfer you can find out youself by going to the federal inmate locator an type in his id number an it will tell you,but if he is in a federal prison he will be transfer to the transfer facility in oklahoma city first before they transfer him to the new facility hes goin to. they just transfer my husband back here in may. thats how i foud out.