The state Health Planning and Development Agency approved the move in 2010, despite opposition from Brookwood Medical Center and St. Vincent's Health System.
Then a Montgomery circuit judge reversed that decision in July.
The state Court of Civil Appeals decided unanimously Friday to reverse the lower court judge and support the ruling by the health planning agency.
The appeals court said Jefferson County has too many hospital beds and the move would reduce that number because the new Trinity Medical Center will have fewer beds than the current hospital.