modelBinding works when using model but not with viewmodel

I'm trying to get a dropdown show the right value when editing using a viewmodel but it only works when i pass the complete model to the view.

When I do it like this and there is already a contact selected it shows that contact in the edit screen.

Model

public class ClientModel
{
  public int ID { get; set; }
  public int ContactID { get; set; }
  //Other atributes
}

View EditContact

@model Project.Models.ClientModel
@Html.DropDownListFor(model => model.ContactID , (SelectList)ViewBag.ContactID, "select a contact")

Controller

   public ActionResult EditContact(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }

        var Contact = db.Contacts.ToList();
        ViewBagID.Contact = new SelectList(Contact.AsEnumerable(), "ID", "name", "Contact");
        ClientModel model= db.ClientModel.Find(id);

        return View(model);
    }

But when I do it like this and there is already a contact selected the dropdownlist shows select contact.

Model

public class ClientModel
{
  public int ID { get; set; }
  public int ContactID { get; set; }
  //Other atributes
}

ViewModel

public class ClientEditContactModel
{
  public int ID { get; set; }
  public int ContactID { get; set; }
}

View EditContact

@model Project.Models.ClientEditContactModel
@Html.DropDownListFor(model => model.ContactID, (SelectList)ViewBag.ContactID, "select a contact")

Controller

   public ActionResult EditContact(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }

        var Contact = db.Contacts.ToList();
        ViewBag.ContactID = new SelectList(Contact.AsEnumerable(), "ID", "name", "Contact");
        ClientModel client= db.ClientModel.Find(id);
        ClientEditContactModel model = new ClientEditContactModel();

        model.ID = client.ID;
        model.ContactID = client.ContactID 

        return View(model);
    }

How do i fix this with the viewmodel?

Edit I've made some typo's in my code so I fixed them but because of them i found the answer see below.