Participants with questions should contact the Service Center at 877.644. Forms and Help. Forms. Help.If you have questions, contact Ohio Deferred Compensation. If you already have an account with Ohio DC you will need to Login and choose Add New Account to enroll. For further information, the employee should contact our Service Center at 877-644-6457 and press 3 to speak with an Account Executive. Call 1-888-867-5175 Email us. Call Number: KF 390 .