Please, read my comment to the question.
This should work as well:
var data = db.expense
.Join(db.Itemmodels, q => q.ITEM, o => o.id, (q, ITEM) => new { q, ITEM })
.Where(o => o.q.EntryDate == DateTime.Today && o.q.Manager == managerName && o.q.THROUGH != "CashTransfer")
.ToList();