static void Main(string[] args) { var a = new A { FirstName = "Gregory", LastName = "House", Age = "39", SecondAge = new C() { Age = 99 } }; var config = new MapperConfiguration(); config.CreateMap <A, B>() .Ignore(i => i.FirstName) .ForMember(i => i.Age, i => int.Parse(i.Age)); config.CreateCustomMap <B, A>(i => new A { FirstName = i.FirstName, LastName = i.LastName }); config.CreateMap <C, D>(); Mapper.Initialize(config); var b1 = Mapper.Map <A, B>(a); var b2 = Mapper.Map <B, A>(b1); System.Console.ReadLine(); }