diff --git a/src/AspNet.Security.OpenId/Events/OpenIdRedirectContext.cs b/src/AspNet.Security.OpenId/Events/OpenIdRedirectContext.cs
new file mode 100644
index 00000000..ade4277f
--- /dev/null
+++ b/src/AspNet.Security.OpenId/Events/OpenIdRedirectContext.cs
@@ -0,0 +1,23 @@
+using Microsoft.AspNetCore.Authentication;
+using Microsoft.AspNetCore.Http;
+
+namespace AspNet.Security.OpenId.Events
+{
+    public class OpenIdRedirectContext : PropertiesContext<OpenIdAuthenticationOptions>
+    {
+        public OpenIdRedirectContext(HttpContext context,
+            AuthenticationScheme scheme,
+            OpenIdAuthenticationOptions options,
+            AuthenticationProperties properties,
+            OpenIdAuthenticationMessage message)
+            : base(context, scheme, options, properties)
+        {
+            ProtocolMessage = message;
+        }
+
+        /// <summary>
+        /// Gets or sets the protocol message that has been generated by the handler up to this point.
+        /// </summary>
+        public OpenIdAuthenticationMessage ProtocolMessage { get; set; }
+    }
+}
diff --git a/src/AspNet.Security.OpenId/OpenIdAuthenticationEvents.cs b/src/AspNet.Security.OpenId/OpenIdAuthenticationEvents.cs
index 38768842..00f9c306 100644
--- a/src/AspNet.Security.OpenId/OpenIdAuthenticationEvents.cs
+++ b/src/AspNet.Security.OpenId/OpenIdAuthenticationEvents.cs
@@ -6,6 +6,7 @@
 
 using System;
 using System.Threading.Tasks;
+using AspNet.Security.OpenId.Events;
 using Microsoft.AspNetCore.Authentication;
 
 namespace AspNet.Security.OpenId
@@ -21,11 +22,23 @@ public class OpenIdAuthenticationEvents : RemoteAuthenticationEvents
         /// </summary>
         public Func<OpenIdAuthenticatedContext, Task> OnAuthenticated { get; set; } = context => Task.FromResult<object>(null);
 
+        /// <summary>
+        /// Defines a notification invoked prior to redirecting to the identity provider.
+        /// </summary>
+        public Func<OpenIdRedirectContext, Task> OnRedirectToIdentityProvider { get; set; } = context => Task.CompletedTask;
+
         /// <summary>
         /// Defines a notification invoked when the user is authenticated by the identity provider.
         /// </summary>
         /// <param name="context">The context of the event carries information in and results out.</param>
         /// <returns>Task to enable asynchronous execution</returns>
         public virtual Task Authenticated(OpenIdAuthenticatedContext context) => OnAuthenticated(context);
+
+        /// <summary>
+        /// Defines a notification invoked prior to redirecting to the identity provider.
+        /// </summary>
+        /// <param name="context">The context of the event carries information in and results out.</param>
+        /// <returns>Task to enable asynchronous execution</returns>
+        public virtual Task RedirectToIdentityProvider(OpenIdRedirectContext context) => OnRedirectToIdentityProvider(context);
     }
 }
diff --git a/src/AspNet.Security.OpenId/OpenIdAuthenticationHandler.cs b/src/AspNet.Security.OpenId/OpenIdAuthenticationHandler.cs
index d71dfe58..23636963 100644
--- a/src/AspNet.Security.OpenId/OpenIdAuthenticationHandler.cs
+++ b/src/AspNet.Security.OpenId/OpenIdAuthenticationHandler.cs
@@ -12,6 +12,7 @@
 using System.Security.Claims;
 using System.Text.Encodings.Web;
 using System.Threading.Tasks;
+using AspNet.Security.OpenId.Events;
 using JetBrains.Annotations;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.WebUtilities;
@@ -323,6 +324,10 @@ protected override async Task HandleChallengeAsync(AuthenticationProperties prop
                     value: string.Join(",", Options.Attributes.Select(attribute => attribute.Key)));
             }
 
+            var context = new OpenIdRedirectContext(Context, Scheme, Options, properties, message);
+
+            await Events.RedirectToIdentityProvider(context);
+
             var address = QueryHelpers.AddQueryString(configuration.AuthenticationEndpoint,
                 message.GetParameters()
                     .ToDictionary(parameter => parameter.Key,