La. R.S. 11:217

Any member of a state or statewide retirement system who has completed twenty years of creditable service, and who has withdrawn from active service prior to the age at which he is eligible to begin receiving retirement benefits, shall be eligible in the event of total and permanent disability, for the lesser of all nonservice related disability benefits provided by his retirement system, or the normal vested retirement benefit. Upon attaining the normal vested retirement age, his disability benefit shall cease and he shall receive his full vested regular retirement.