diff --git a/src/Microsoft.AspNet.Security/Authorization/AuthorizationPolicy.cs b/src/Microsoft.AspNet.Security/Authorization/AuthorizationPolicy.cs
new file mode 100644
index 0000000000..505f873aac
--- /dev/null
+++ b/src/Microsoft.AspNet.Security/Authorization/AuthorizationPolicy.cs
@@ -0,0 +1,46 @@
+// Copyright (c) Microsoft Open Technologies, Inc.
+// All Rights Reserved
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR
+// CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
+// WITHOUT LIMITATION ANY IMPLIED WARRANTIES OR CONDITIONS OF
+// TITLE, FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABLITY OR
+// NON-INFRINGEMENT.
+// See the Apache 2 License for the specific language governing
+// permissions and limitations under the License.
+
+using System.Collections.Generic;
+using System.Security.Claims;
+using System.Threading.Tasks;
+
+namespace Microsoft.AspNet.Security.Authorization
+{
+    /// <summary>
+    /// This class provides a base implementation for <see cref="IAuthorizationPolicy" />
+    /// </summary>
+    public abstract class AuthorizationPolicy : IAuthorizationPolicy
+    {
+        public int Order { get; set; }
+        
+        public virtual Task ApplyingAsync(AuthorizationPolicyContext context)
+        {
+            return Task.FromResult(0);
+        }
+
+        public virtual Task ApplyAsync(AuthorizationPolicyContext context) 
+        {
+            return Task.FromResult(0);
+        }
+
+        public virtual Task AppliedAsync(AuthorizationPolicyContext context)
+        {
+            return Task.FromResult(0);
+        }
+    }
+}
diff --git a/src/Microsoft.AspNet.Security/Authorization/AuthorizationPolicyContext.cs b/src/Microsoft.AspNet.Security/Authorization/AuthorizationPolicyContext.cs
index ab65513ab5..fabc41d05d 100644
--- a/src/Microsoft.AspNet.Security/Authorization/AuthorizationPolicyContext.cs
+++ b/src/Microsoft.AspNet.Security/Authorization/AuthorizationPolicyContext.cs
@@ -16,6 +16,11 @@ namespace Microsoft.AspNet.Security.Authorization
             Claims = (claims ?? Enumerable.Empty<Claim>()).ToList();
             User = user;
             Resource = resource;
+
+            // user claims are copied to a new and mutable list
+            UserClaims = user != null
+                ? user.Claims.ToList()
+                : new List<Claim>();
         }
 
         /// <summary>
@@ -28,6 +33,14 @@ namespace Microsoft.AspNet.Security.Authorization
         /// </summary>
         public ClaimsPrincipal User { get; private set; }
 
+        /// <summary>
+        /// The claims of the user.
+        /// </summary>
+        /// <remarks>
+        /// This list can be modified by policies for retries.
+        /// </remarks>
+        public IList<Claim> UserClaims { get; private set; }
+
         /// <summary>
         /// An optional resource associated to the check.
         /// </summary>
diff --git a/src/Microsoft.AspNet.Security/Authorization/AuthorizationServiceExtensions.cs b/src/Microsoft.AspNet.Security/Authorization/AuthorizationServiceExtensions.cs
new file mode 100644
index 0000000000..70d52bf8d1
--- /dev/null
+++ b/src/Microsoft.AspNet.Security/Authorization/AuthorizationServiceExtensions.cs
@@ -0,0 +1,59 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Security.Claims;
+using System.Threading.Tasks;
+
+namespace Microsoft.AspNet.Security.Authorization
+{
+    public static class AuthorizationServiceExtensions
+    {
+        /// <summary>
+        /// Checks if a user has specific claims.
+        /// </summary>
+        /// <param name="claim">The claim to check against a specific user.</param>
+        /// <param name="user">The user to check claims against.</param>
+        /// <returns><value>true</value> when the user fulfills one of the claims, <value>false</value> otherwise.</returns>
+        public static Task<bool> AuthorizeAsync(this IAuthorizationService service, Claim claim, ClaimsPrincipal user)
+        {
+            return service.AuthorizeAsync(new Claim[] { claim }, user);
+        }
+
+        /// <summary>
+        /// Checks if a user has specific claims.
+        /// </summary>
+        /// <param name="claim">The claim to check against a specific user.</param>
+        /// <param name="user">The user to check claims against.</param>
+        /// <returns><value>true</value> when the user fulfills one of the claims, <value>false</value> otherwise.</returns>
+        public static bool Authorize(this IAuthorizationService service, Claim claim, ClaimsPrincipal user)
+        {
+            return service.Authorize(new Claim[] { claim }, user);
+        }
+
+        /// <summary>
+        /// Checks if a user has specific claims for a specific context obj.
+        /// </summary>
+        /// <param name="claim">The claim to check against a specific user.</param>
+        /// <param name="user">The user to check claims against.</param>
+        /// <param name="resource">The resource the claims should be check with.</param>
+        /// <returns><value>true</value> when the user fulfills one of the claims, <value>false</value> otherwise.</returns>
+        public static Task<bool> AuthorizeAsync(this IAuthorizationService service, Claim claim, ClaimsPrincipal user, object resource)
+        {
+            return service.AuthorizeAsync(new Claim[] { claim }, user, resource);
+        }
+
+        /// <summary>
+        /// Checks if a user has specific claims for a specific context obj.
+        /// </summary>
+        /// <param name="claim">The claimsto check against a specific user.</param>
+        /// <param name="user">The user to check claims against.</param>
+        /// <param name="resource">The resource the claims should be check with.</param>
+        /// <returns><value>true</value> when the user fulfills one of the claims, <value>false</value> otherwise.</returns>
+        public static bool Authorize(this IAuthorizationService service, Claim claim, ClaimsPrincipal user, object resource)
+        {
+            return service.Authorize(new Claim[] { claim }, user, resource);
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/Microsoft.AspNet.Security/Authorization/DefaultAuthorizationService.cs b/src/Microsoft.AspNet.Security/Authorization/DefaultAuthorizationService.cs
index 09a4d9a95b..544caac07f 100644
--- a/src/Microsoft.AspNet.Security/Authorization/DefaultAuthorizationService.cs
+++ b/src/Microsoft.AspNet.Security/Authorization/DefaultAuthorizationService.cs
@@ -55,7 +55,7 @@ namespace Microsoft.AspNet.Security.Authorization
                 {
                     if (context.User != null)
                     {
-                        if (context.Claims.Any(claim => user.HasClaim(claim.Type, claim.Value)))
+                        if (ClaimsMatch(context.Claims, context.UserClaims))
                         {
                             context.Authorized = true;
                         }
@@ -95,5 +95,16 @@ namespace Microsoft.AspNet.Security.Authorization
         {
             return AuthorizeAsync(claims, user, resource).Result;
         }
+
+        private bool ClaimsMatch([NotNull] IEnumerable<Claim> x, [NotNull] IEnumerable<Claim> y)
+        {
+            return x.Any(claim => 
+                        y.Any(userClaim => 
+                            string.Equals(claim.Type, userClaim.Type, StringComparison.OrdinalIgnoreCase) &&
+                            string.Equals(claim.Value, userClaim.Value, StringComparison.Ordinal)
+                        )
+                    );
+
+        }
     }
 }
\ No newline at end of file
diff --git a/test/Microsoft.AspNet.Security.Test/DefaultAuthorizationServiceTests.cs b/test/Microsoft.AspNet.Security.Test/DefaultAuthorizationServiceTests.cs
index 8be366974b..9c36c54bf6 100644
--- a/test/Microsoft.AspNet.Security.Test/DefaultAuthorizationServiceTests.cs
+++ b/test/Microsoft.AspNet.Security.Test/DefaultAuthorizationServiceTests.cs
@@ -243,7 +243,7 @@ namespace Microsoft.AspNet.Security.Test
         }
  
         [Fact]
-        public void Check_ApplyCanMutateClaims()
+        public void Check_ApplyCanMutateCheckedClaims()
         {
 
             // Arrange
@@ -272,5 +272,35 @@ namespace Microsoft.AspNet.Security.Test
             // Assert
             Assert.True(allowed);
         }
+
+        [Fact]
+        public void Check_PoliciesCanMutateUsersClaims()
+        {
+
+            // Arrange
+            var user = new ClaimsPrincipal(
+                new ClaimsIdentity(new Claim[0], "Basic")
+                );
+
+            var policies = new IAuthorizationPolicy[] {
+                new FakePolicy() {
+                    ApplyAsyncAction = (context) => { 
+                        if (!context.Authorized) 
+                        {
+                            context.UserClaims.Add(new Claim("Permission", "CanDeleteComments")); 
+                            context.Retry = true;
+                        }
+                    }
+                }
+            };
+
+            var authorizationService = new DefaultAuthorizationService(policies);
+            
+            // Act
+            var allowed = authorizationService.Authorize(new Claim("Permission", "CanDeleteComments"), user);
+
+            // Assert
+            Assert.True(allowed);
+        }
     }
 }