diff --git a/resources/celerity/map.php b/resources/celerity/map.php
index 99f3333106..2dd5cf0966 100644
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -9,7 +9,7 @@ return array(
   'names' => array(
     'conpherence.pkg.css' => '3c8a0668',
     'conpherence.pkg.js' => '020aebcf',
-    'core.pkg.css' => '7a73ffc5',
+    'core.pkg.css' => 'e0f5d66f',
     'core.pkg.js' => '5c737607',
     'differential.pkg.css' => 'b8df73d4',
     'differential.pkg.js' => '67c9ea4c',
@@ -151,7 +151,7 @@ return array(
     'rsrc/css/phui/phui-document.css' => '52b748a5',
     'rsrc/css/phui/phui-feed-story.css' => 'a0c05029',
     'rsrc/css/phui/phui-fontkit.css' => '9b714a5e',
-    'rsrc/css/phui/phui-form-view.css' => '0807e7ac',
+    'rsrc/css/phui/phui-form-view.css' => '01b796c0',
     'rsrc/css/phui/phui-form.css' => '159e2d9c',
     'rsrc/css/phui/phui-head-thing.css' => 'd7f293df',
     'rsrc/css/phui/phui-header-view.css' => '93cea4ec',
@@ -502,6 +502,7 @@ return array(
     'rsrc/js/phui/behavior-phui-selectable-list.js' => 'b26a41e4',
     'rsrc/js/phui/behavior-phui-submenu.js' => 'b5e9bff9',
     'rsrc/js/phui/behavior-phui-tab-group.js' => '242aa08b',
+    'rsrc/js/phui/behavior-phui-timer-control.js' => 'f84bcbf4',
     'rsrc/js/phuix/PHUIXActionListView.js' => 'c68f183f',
     'rsrc/js/phuix/PHUIXActionView.js' => 'aaa08f3b',
     'rsrc/js/phuix/PHUIXAutocomplete.js' => '58cc4ab8',
@@ -650,6 +651,7 @@ return array(
     'javelin-behavior-phui-selectable-list' => 'b26a41e4',
     'javelin-behavior-phui-submenu' => 'b5e9bff9',
     'javelin-behavior-phui-tab-group' => '242aa08b',
+    'javelin-behavior-phui-timer-control' => 'f84bcbf4',
     'javelin-behavior-phuix-example' => 'c2c500a7',
     'javelin-behavior-policy-control' => '0eaa33a9',
     'javelin-behavior-policy-rule-editor' => '9347f172',
@@ -817,7 +819,7 @@ return array(
     'phui-font-icon-base-css' => 'd7994e06',
     'phui-fontkit-css' => '9b714a5e',
     'phui-form-css' => '159e2d9c',
-    'phui-form-view-css' => '0807e7ac',
+    'phui-form-view-css' => '01b796c0',
     'phui-head-thing-view-css' => 'd7f293df',
     'phui-header-view-css' => '93cea4ec',
     'phui-hovercard' => '074f0783',
@@ -2111,6 +2113,11 @@ return array(
       'javelin-stratcom',
       'javelin-dom',
     ),
+    'f84bcbf4' => array(
+      'javelin-behavior',
+      'javelin-stratcom',
+      'javelin-dom',
+    ),
     'f8c4e135' => array(
       'javelin-install',
       'javelin-dom',
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index 8f06586a68..e3287df74c 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -2195,6 +2195,8 @@ phutil_register_library_map(array(
     'PhabricatorAuthChallengeGarbageCollector' => 'applications/auth/garbagecollector/PhabricatorAuthChallengeGarbageCollector.php',
     'PhabricatorAuthChallengePHIDType' => 'applications/auth/phid/PhabricatorAuthChallengePHIDType.php',
     'PhabricatorAuthChallengeQuery' => 'applications/auth/query/PhabricatorAuthChallengeQuery.php',
+    'PhabricatorAuthChallengeStatusController' => 'applications/auth/controller/mfa/PhabricatorAuthChallengeStatusController.php',
+    'PhabricatorAuthChallengeUpdate' => 'applications/auth/view/PhabricatorAuthChallengeUpdate.php',
     'PhabricatorAuthChangePasswordAction' => 'applications/auth/action/PhabricatorAuthChangePasswordAction.php',
     'PhabricatorAuthConduitAPIMethod' => 'applications/auth/conduit/PhabricatorAuthConduitAPIMethod.php',
     'PhabricatorAuthConduitTokenRevoker' => 'applications/auth/revoker/PhabricatorAuthConduitTokenRevoker.php',
@@ -7925,6 +7927,8 @@ phutil_register_library_map(array(
     'PhabricatorAuthChallengeGarbageCollector' => 'PhabricatorGarbageCollector',
     'PhabricatorAuthChallengePHIDType' => 'PhabricatorPHIDType',
     'PhabricatorAuthChallengeQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
+    'PhabricatorAuthChallengeStatusController' => 'PhabricatorAuthController',
+    'PhabricatorAuthChallengeUpdate' => 'Phobject',
     'PhabricatorAuthChangePasswordAction' => 'PhabricatorSystemAction',
     'PhabricatorAuthConduitAPIMethod' => 'ConduitAPIMethod',
     'PhabricatorAuthConduitTokenRevoker' => 'PhabricatorAuthRevoker',
diff --git a/src/applications/auth/application/PhabricatorAuthApplication.php b/src/applications/auth/application/PhabricatorAuthApplication.php
index 52cf01b2aa..4e0baff229 100644
--- a/src/applications/auth/application/PhabricatorAuthApplication.php
+++ b/src/applications/auth/application/PhabricatorAuthApplication.php
@@ -97,6 +97,8 @@ final class PhabricatorAuthApplication extends PhabricatorApplication {
             'PhabricatorAuthFactorProviderViewController',
           'message/(?P<id>[1-9]\d*)/' =>
             'PhabricatorAuthFactorProviderMessageController',
+          'challenge/status/(?P<id>[1-9]\d*)/' =>
+            'PhabricatorAuthChallengeStatusController',
         ),
 
         'message/' => array(
diff --git a/src/applications/auth/controller/mfa/PhabricatorAuthChallengeStatusController.php b/src/applications/auth/controller/mfa/PhabricatorAuthChallengeStatusController.php
new file mode 100644
index 0000000000..884bbaad6d
--- /dev/null
+++ b/src/applications/auth/controller/mfa/PhabricatorAuthChallengeStatusController.php
@@ -0,0 +1,40 @@
+<?php
+
+final class PhabricatorAuthChallengeStatusController
+  extends PhabricatorAuthController {
+
+  public function handleRequest(AphrontRequest $request) {
+    $viewer = $this->getViewer();
+    $id = $request->getURIData('id');
+    $now = PhabricatorTime::getNow();
+
+    $result = new PhabricatorAuthChallengeUpdate();
+
+    $challenge = id(new PhabricatorAuthChallengeQuery())
+      ->setViewer($viewer)
+      ->withIDs(array($id))
+      ->withUserPHIDs(array($viewer->getPHID()))
+      ->withChallengeTTLBetween($now, null)
+      ->executeOne();
+    if ($challenge) {
+      $config = id(new PhabricatorAuthFactorConfigQuery())
+        ->setViewer($viewer)
+        ->withPHIDs(array($challenge->getFactorPHID()))
+        ->executeOne();
+      if ($config) {
+        $provider = $config->getFactorProvider();
+        $factor = $provider->getFactor();
+
+        $result = $factor->newChallengeStatusView(
+          $config,
+          $provider,
+          $viewer,
+          $challenge);
+      }
+    }
+
+    return id(new AphrontAjaxResponse())
+      ->setContent($result->newContent());
+  }
+
+}
diff --git a/src/applications/auth/factor/PhabricatorAuthFactor.php b/src/applications/auth/factor/PhabricatorAuthFactor.php
index 912a2c31c9..d7e6e60ecc 100644
--- a/src/applications/auth/factor/PhabricatorAuthFactor.php
+++ b/src/applications/auth/factor/PhabricatorAuthFactor.php
@@ -80,6 +80,14 @@ abstract class PhabricatorAuthFactor extends Phobject {
     return array();
   }
 
+  public function newChallengeStatusView(
+    PhabricatorAuthFactorConfig $config,
+    PhabricatorAuthFactorProvider $provider,
+    PhabricatorUser $viewer,
+    PhabricatorAuthChallenge $challenge) {
+    return null;
+  }
+
   /**
    * Is this a factor which depends on the user's contact number?
    *
@@ -210,8 +218,6 @@ abstract class PhabricatorAuthFactor extends Phobject {
           get_class($this)));
     }
 
-    $result->setIssuedChallenges($challenges);
-
     return $result;
   }
 
@@ -242,8 +248,6 @@ abstract class PhabricatorAuthFactor extends Phobject {
           get_class($this)));
     }
 
-    $result->setIssuedChallenges($challenges);
-
     return $result;
   }
 
@@ -339,9 +343,18 @@ abstract class PhabricatorAuthFactor extends Phobject {
         ->setIcon('fa-commenting', 'green');
     }
 
-    return id(new PHUIFormTimerControl())
+    $control = id(new PHUIFormTimerControl())
       ->setIcon($icon)
       ->appendChild($error);
+
+    $status_challenge = $result->getStatusChallenge();
+    if ($status_challenge) {
+      $id = $status_challenge->getID();
+      $uri = "/auth/mfa/challenge/status/{$id}/";
+      $control->setUpdateURI($uri);
+    }
+
+    return $control;
   }
 
 
diff --git a/src/applications/auth/factor/PhabricatorAuthFactorResult.php b/src/applications/auth/factor/PhabricatorAuthFactorResult.php
index f03c3674da..b5da379545 100644
--- a/src/applications/auth/factor/PhabricatorAuthFactorResult.php
+++ b/src/applications/auth/factor/PhabricatorAuthFactorResult.php
@@ -11,6 +11,7 @@ final class PhabricatorAuthFactorResult
   private $value;
   private $issuedChallenges = array();
   private $icon;
+  private $statusChallenge;
 
   public function setAnsweredChallenge(PhabricatorAuthChallenge $challenge) {
     if (!$challenge->getIsAnsweredChallenge()) {
@@ -34,6 +35,15 @@ final class PhabricatorAuthFactorResult
     return $this->answeredChallenge;
   }
 
+  public function setStatusChallenge(PhabricatorAuthChallenge $challenge) {
+    $this->statusChallenge = $challenge;
+    return $this;
+  }
+
+  public function getStatusChallenge() {
+    return $this->statusChallenge;
+  }
+
   public function getIsValid() {
     return (bool)$this->getAnsweredChallenge();
   }
@@ -83,16 +93,6 @@ final class PhabricatorAuthFactorResult
     return $this->value;
   }
 
-  public function setIssuedChallenges(array $issued_challenges) {
-    assert_instances_of($issued_challenges, 'PhabricatorAuthChallenge');
-    $this->issuedChallenges = $issued_challenges;
-    return $this;
-  }
-
-  public function getIssuedChallenges() {
-    return $this->issuedChallenges;
-  }
-
   public function setIcon(PHUIIconView $icon) {
     $this->icon = $icon;
     return $this;
diff --git a/src/applications/auth/factor/PhabricatorDuoAuthFactor.php b/src/applications/auth/factor/PhabricatorDuoAuthFactor.php
index 4be4c15ea8..66bd7c9ebd 100644
--- a/src/applications/auth/factor/PhabricatorDuoAuthFactor.php
+++ b/src/applications/auth/factor/PhabricatorDuoAuthFactor.php
@@ -585,7 +585,7 @@ final class PhabricatorDuoAuthFactor
       $result = $this->newDuoFuture($provider)
         ->setHTTPMethod('GET')
         ->setMethod('auth_status', $parameters)
-        ->setTimeout(5)
+        ->setTimeout(3)
         ->resolve();
 
       $state = $result['response']['result'];
@@ -661,15 +661,6 @@ final class PhabricatorDuoAuthFactor
     PhabricatorAuthFactorResult $result) {
 
     $control = $this->newAutomaticControl($result);
-    if (!$control) {
-      $result = $this->newResult()
-        ->setIsContinue(true)
-        ->setErrorMessage(
-          pht(
-            'A challenge has been sent to your phone. Open the Duo '.
-            'application and confirm the challenge, then continue.'));
-      $control = $this->newAutomaticControl($result);
-    }
 
     $control
       ->setLabel(pht('Duo'))
@@ -689,7 +680,27 @@ final class PhabricatorDuoAuthFactor
     PhabricatorUser $viewer,
     AphrontRequest $request,
     array $challenges) {
-    return $this->newResult();
+
+    $result = $this->newResult()
+      ->setIsContinue(true)
+      ->setErrorMessage(
+        pht(
+          'A challenge has been sent to your phone. Open the Duo '.
+          'application and confirm the challenge, then continue.'));
+
+    $challenge = $this->getChallengeForCurrentContext(
+      $config,
+      $viewer,
+      $challenges);
+    if ($challenge) {
+      $result
+        ->setStatusChallenge($challenge)
+        ->setIcon(
+          id(new PHUIIconView())
+            ->setIcon('fa-refresh', 'green ph-spin'));
+    }
+
+    return $result;
   }
 
   private function newDuoFuture(PhabricatorAuthFactorProvider $provider) {
@@ -790,4 +801,54 @@ final class PhabricatorDuoAuthFactor
         $hostname));
   }
 
+  public function newChallengeStatusView(
+    PhabricatorAuthFactorConfig $config,
+    PhabricatorAuthFactorProvider $provider,
+    PhabricatorUser $viewer,
+    PhabricatorAuthChallenge $challenge) {
+
+    $duo_xaction = $challenge->getChallengeKey();
+
+    $parameters = array(
+      'txid' => $duo_xaction,
+    );
+
+    $default_result = id(new PhabricatorAuthChallengeUpdate())
+      ->setRetry(true);
+
+    try {
+      $result = $this->newDuoFuture($provider)
+        ->setHTTPMethod('GET')
+        ->setMethod('auth_status', $parameters)
+        ->setTimeout(5)
+        ->resolve();
+
+      $state = $result['response']['result'];
+    } catch (HTTPFutureCURLResponseStatus $exception) {
+      // If we failed or timed out, retry. Usually, this is a timeout.
+      return id(new PhabricatorAuthChallengeUpdate())
+        ->setRetry(true);
+    }
+
+    // For now, don't update the view for anything but an "Allow". Updates
+    // here are just about providing more visual feedback for user convenience.
+    if ($state !== 'allow') {
+      return id(new PhabricatorAuthChallengeUpdate())
+        ->setRetry(false);
+    }
+
+    $icon = id(new PHUIIconView())
+      ->setIcon('fa-check-circle-o', 'green');
+
+    $view = id(new PHUIFormTimerControl())
+      ->setIcon($icon)
+      ->appendChild(pht('You responded to this challenge correctly.'))
+      ->newTimerView();
+
+    return id(new PhabricatorAuthChallengeUpdate())
+      ->setState('allow')
+      ->setRetry(false)
+      ->setMarkup($view);
+  }
+
 }
diff --git a/src/applications/auth/view/PhabricatorAuthChallengeUpdate.php b/src/applications/auth/view/PhabricatorAuthChallengeUpdate.php
new file mode 100644
index 0000000000..a8ae5b8825
--- /dev/null
+++ b/src/applications/auth/view/PhabricatorAuthChallengeUpdate.php
@@ -0,0 +1,44 @@
+<?php
+
+final class PhabricatorAuthChallengeUpdate
+  extends Phobject {
+
+  private $retry = false;
+  private $state;
+  private $markup;
+
+  public function setRetry($retry) {
+    $this->retry = $retry;
+    return $this;
+  }
+
+  public function getRetry() {
+    return $this->retry;
+  }
+
+  public function setState($state) {
+    $this->state = $state;
+    return $this;
+  }
+
+  public function getState() {
+    return $this->state;
+  }
+
+  public function setMarkup($markup) {
+    $this->markup = $markup;
+    return $this;
+  }
+
+  public function getMarkup() {
+    return $this->markup;
+  }
+
+  public function newContent() {
+    return array(
+      'retry' => $this->getRetry(),
+      'state' => $this->getState(),
+      'markup' => $this->getMarkup(),
+    );
+  }
+}
diff --git a/src/view/form/control/PHUIFormTimerControl.php b/src/view/form/control/PHUIFormTimerControl.php
index 7229d649e9..090de2c8e4 100644
--- a/src/view/form/control/PHUIFormTimerControl.php
+++ b/src/view/form/control/PHUIFormTimerControl.php
@@ -3,6 +3,7 @@
 final class PHUIFormTimerControl extends AphrontFormControl {
 
   private $icon;
+  private $updateURI;
 
   public function setIcon(PHUIIconView $icon) {
     $this->icon = $icon;
@@ -13,11 +14,24 @@ final class PHUIFormTimerControl extends AphrontFormControl {
     return $this->icon;
   }
 
+  public function setUpdateURI($update_uri) {
+    $this->updateURI = $update_uri;
+    return $this;
+  }
+
+  public function getUpdateURI() {
+    return $this->updateURI;
+  }
+
   protected function getCustomControlClass() {
     return 'phui-form-timer';
   }
 
   protected function renderInput() {
+    return $this->newTimerView();
+  }
+
+  public function newTimerView() {
     $icon_cell = phutil_tag(
       'td',
       array(
@@ -34,7 +48,21 @@ final class PHUIFormTimerControl extends AphrontFormControl {
 
     $row = phutil_tag('tr', array(), array($icon_cell, $content_cell));
 
-    return phutil_tag('table', array(), $row);
+    $node_id = null;
+
+    $update_uri = $this->getUpdateURI();
+    if ($update_uri) {
+      $node_id = celerity_generate_unique_node_id();
+
+      Javelin::initBehavior(
+        'phui-timer-control',
+        array(
+          'nodeID' => $node_id,
+          'uri' => $update_uri,
+        ));
+    }
+
+    return phutil_tag('table', array('id' => $node_id), $row);
   }
 
 }
diff --git a/webroot/rsrc/css/phui/phui-form-view.css b/webroot/rsrc/css/phui/phui-form-view.css
index 3368bcaafb..accce86819 100644
--- a/webroot/rsrc/css/phui/phui-form-view.css
+++ b/webroot/rsrc/css/phui/phui-form-view.css
@@ -578,3 +578,17 @@ properly, and submit values. */
 .mfa-form-enroll-button {
   text-align: center;
 }
+
+.phui-form-timer-updated {
+  animation: phui-form-timer-fade-in 2s linear;
+}
+
+
+@keyframes phui-form-timer-fade-in {
+  0% {
+    background-color: {$lightyellow};
+  }
+  100% {
+    background-color: transparent;
+  }
+}
diff --git a/webroot/rsrc/js/phui/behavior-phui-timer-control.js b/webroot/rsrc/js/phui/behavior-phui-timer-control.js
new file mode 100644
index 0000000000..d5b73a5ee2
--- /dev/null
+++ b/webroot/rsrc/js/phui/behavior-phui-timer-control.js
@@ -0,0 +1,41 @@
+/**
+ * @provides javelin-behavior-phui-timer-control
+ * @requires javelin-behavior
+ *           javelin-stratcom
+ *           javelin-dom
+ */
+
+JX.behavior('phui-timer-control', function(config) {
+  var node = JX.$(config.nodeID);
+  var uri = config.uri;
+  var state = null;
+
+  function onupdate(result) {
+    var markup = result.markup;
+    if (markup) {
+      var new_node = JX.$H(markup).getFragment().firstChild;
+      JX.DOM.replace(node, new_node);
+      node = new_node;
+
+      // If the overall state has changed from the previous display state,
+      // animate the control to draw the user's attention to the state change.
+      if (result.state !== state) {
+        state = result.state;
+        JX.DOM.alterClass(node, 'phui-form-timer-updated', true);
+      }
+    }
+
+    var retry = result.retry;
+    if (retry) {
+      setTimeout(update, 1000);
+    }
+  }
+
+  function update() {
+    new JX.Request(uri, onupdate)
+      .setTimeout(10000)
+      .send();
+  }
+
+  update();
+});