using System;

public class Program

{

    public enum ChargeTerm

    {

        Monthly = 0,

        Annual = 1

    }

    public class Charge 

    {

        public ChargeTerm Term { get; set; }

    }

    public static void Main()

    {

        int? dbValue = null;

        var charge = new Charge();

        charge.Term = (ChargeTerm)dbValue;

    }

}