using System.Collections.Generic;
public static void Main(string[] args)
List<Claim> currentClaims = new List<Claim>();
currentClaims.Add(new Claim() { ID = 1 });
List<Claim> newClaims = new List<Claim>();
newClaims.Add(new Claim() { ID = 1 });
newClaims.Add(new Claim() { ID = 2 });
foreach (var newClaim in newClaims)
var existingClaim = currentClaims.FirstOrDefault(currentClaim => currentClaim.ID == newClaim.ID);
if (existingClaim == null)
Console.WriteLine("Claim ID" + newClaim.ID + " is new");
Console.WriteLine("Claim ID" + existingClaim.ID + " is existing");
public int ID { get; set; }