2000 Acura TL will not turn over. on 1999 Lexus RX300

My 2000 Acura TL will not even try to start. Turning the ignition brings on the dash lights but only yields a click when turned to the start position. The battery and Alternator have been tested good. The starter had been working fine with no indications of difficulty. Could it be the starter? I appreciate your thoughts.

Asked by for the 1999 Lexus RX300