Yes and No, You can change your assessment area at any time during the year. There is no time frame or limitation on when or how often. As a bank adds branches, merges, and expands it can change the assessment area to match the expansion. Its just that what ever you have on 12/31 is what you will be reporting for the year.
You may find during the year that the bank started marketing loans in an area outside the existing AA to the point the it has dropped the inside/outside ratio down to 49%. (Thats one reason a periodic analysis of the portfolio needs to be done)
You need to make some serious decisions about expanding the AA. Then rerun the data to see what the new inside/outside ratio is. These kinds of adjustments should not be left to year end. Its the periodic monitoring and adjustments during the year that keep you out of trouble.
You are far to busy at year end to be dealing with AA changes.
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