Scott Andrew Peterson, 36, of Bountiful pleaded guilty to the charge that was amended to a second-degree felony.
Other charges of forcible sexual abuse, forcible sodomy and lewdness were dismissed as part of a plea deal.
Peterson, who was a licensed clinical social worker, engaged in a variety of sexual encounters with the teen “at least a dozen times” according to court documents.
She was 16-years-old when the relationship began.
He was arrested by Centerville police and stripped of his license in November.
His business, "Therapy on the Fly" closed its doors in August.