State tax filing

I'm not sure this is correct.  I live in a co-op and the accounting firm our management uses states that we must reduce the amount of real estate taxes we paid by the amount of star credit (reduction) in our monthly maintenance (time 12).  So if I paid $3,000 in real estate taxes (portion of my annual maintenance which went to pay real estate taxes) and I received an annual STAR credit of, say, $1,500, I can only deduct $1,500 as real estate taxes.  For those of you who wonder about real estate taxes and co-ops, each month our maintenance is reduced by monthly pro-rated star credit).