You could use CASE

Then you could do Case 11,20,8,18,9,12

Looks like Rick has some case in the ext cut here
Switch Function

Thanks Adam.  I watched that video this morning, and tried to figure out the code, but couldn't.  I've never been able to get CASE to work for me.  Since I now know I was on the right track, I will try again.

After watching Switch Function again, and Access Developer 2 again, I still can't get CASE to work, so I give up. I guess I'll just stick to my original code since it works.

You can store all those values in an array, then use a loop to check the values in the array, so you don't need to check them individually (see code below).  If you only have a few values to check, then your original code is fine.  If you have a lot, then the code below is more efficient -- not only is it less repetitious, but it also makes it easier to add additional values in the future should you need to.

    Dim arr As Variant, i As Integer
    arr = Array(11, 20, 8, 18, 9, 12, ... ...)
    A = 0: ST = -1
    For i = 0 To UBound(arr)
        If AccountID = arr(i) Then A = -1: ST = 0
    Next i

I put A=0: ST=-1 at the top, removing the need to use Else.  If AccountID doesn't match any values, then A and ST will remain 0 and -1.

The UBound() function returns the size of the array.  It is zero-based.  If arr has 6 numbers, then UBound(arr) equals 5.

The use of colon (:) in the If Then statement removes the need to have End If, shortening the code even more.  But only use colon when the code is short like that, so it won't hurt readability and manageability.

Thank you Kevin Yip!  That works, and the accounts do change pretty often, so this will make it easy to update them.