BAH pay Change?

What should have happened is you should have received the rate for the new duty station. You'll need to go see the S-1 and get that rectified before the pay discrepancy grows too large.

I'm a little confused here. Are you saying that in 2016 you were getting paid rate A, moved in 2018 and instead of getting paid rate B (a lower amount) you kept getting paid at Rate A? Further, you are wondering if this rate will change over if you get promoted?

To walk this through, rates change based on your rank, dependents, and physical location. When you PCS, the rate you are paid for BAH should change based on the new locality rate. If you are promoted it would change as well.

If you were being paid $1000 per month at your first station as a SGT, and the rate for a SGT at your new unit is $900, then you owe the government that extra amount you were paid. And rest assured they will catch it eventually and take it back all at once effective to the actual change in location (or eligibility). Most likely when you get promoted they will catch this and although a SSG might get more money, you'll also have to pay back any difference between your date of PCS and the date the discrepancy is discovered.

When you have a debt like this, the Army will take the entire amount from your paycheck in a lump sum up to your entire take home pay amount. If after getting a pay check for $0 you still owe money, they will take the rest out of your next paycheck or paychecks. Get with S-1 to fix this now, if this is a really large amount of money you owe finance will often work with you to do a repayment plan if you come to them in advance. Just in case though, make sure you have some money set aside now, just in case they catch this today and take the repayment from your next paycheck.

The higher the rank, the higher the BAH.