diff --git a/ietf/group/forms.py b/ietf/group/forms.py
index 1f04cc827..8e6aab106 100644
--- a/ietf/group/forms.py
+++ b/ietf/group/forms.py
@@ -285,7 +285,7 @@ class ReviewerSettingsForm(forms.ModelForm):
 class AddUnavailablePeriodForm(forms.ModelForm):
     class Meta:
         model = UnavailablePeriod
-        fields = ['start_date', 'end_date', 'availability']
+        fields = ['start_date', 'end_date', 'availability', 'reason']
 
     def __init__(self, *args, **kwargs):
         super(AddUnavailablePeriodForm, self).__init__(*args, **kwargs)
diff --git a/ietf/group/tests_review.py b/ietf/group/tests_review.py
index 66c05bb45..08c4aed7d 100644
--- a/ietf/group/tests_review.py
+++ b/ietf/group/tests_review.py
@@ -428,6 +428,7 @@ class ReviewTests(TestCase):
             'start_date': start_date.isoformat(),
             'end_date': "",
             'availability': "unavailable",
+	    'reason': "Whimsy",
         })
         self.assertEqual(r.status_code, 302)
         period = UnavailablePeriod.objects.get(person=reviewer, team=review_req.team, start_date=start_date)
@@ -437,6 +438,7 @@ class ReviewTests(TestCase):
         msg_content = outbox[0].get_payload(decode=True).decode("utf-8").lower()
         self.assertTrue(start_date.isoformat(), msg_content)
         self.assertTrue("indefinite", msg_content)
+	self.assertEqual(period.reason, "Whimsy")
 
         # end unavailable period
         empty_outbox()
diff --git a/ietf/group/views.py b/ietf/group/views.py
index 3e7343099..662c13ecc 100644
--- a/ietf/group/views.py
+++ b/ietf/group/views.py
@@ -1704,10 +1704,11 @@ def change_reviewer_settings(request, acronym, reviewer_email, group_type=None):
             in_the_past = period.end_date and period.end_date < today
 
             if not in_the_past:
-                msg = "Unavailable for review: {} - {} ({})".format(
+                msg = "Unavailable for review: {} - {} ({})  {}".format(
                     period.start_date.isoformat() if period.start_date else "indefinite",
                     period.end_date.isoformat() if period.end_date else "indefinite",
                     period.get_availability_display(),
+		    period.reason,
                 )
 
                 if period.availability == "unavailable":
diff --git a/ietf/review/admin.py b/ietf/review/admin.py
index 30ace82f8..ec2319f03 100644
--- a/ietf/review/admin.py
+++ b/ietf/review/admin.py
@@ -20,7 +20,7 @@ class ReviewSecretarySettingsAdmin(admin.ModelAdmin):
 admin.site.register(ReviewSecretarySettings, ReviewSecretarySettingsAdmin)
 
 class UnavailablePeriodAdmin(admin.ModelAdmin):
-    list_display = ["person", "team", "start_date", "end_date", "availability"]
+    list_display = ["person", "team", "start_date", "end_date", "availability", "reason"]
     list_display_links = ["person"]
     list_filter = ["team"]
     date_hierarchy = "start_date"
diff --git a/ietf/review/import_from_review_tool.py b/ietf/review/import_from_review_tool.py
index 4e1488d2c..868ab4bb6 100755
--- a/ietf/review/import_from_review_tool.py
+++ b/ietf/review/import_from_review_tool.py
@@ -164,6 +164,7 @@ with db_con.cursor() as c:
                             start_date=None,
                             end_date=end_date,
                             availability="unavailable",
+			    reason="reason",
                         )
 
 # check that we got the needed names
diff --git a/ietf/review/models.py b/ietf/review/models.py
index f52a94e30..97243aebb 100644
--- a/ietf/review/models.py
+++ b/ietf/review/models.py
@@ -60,6 +60,7 @@ class UnavailablePeriod(models.Model):
         ("unavailable", "Completely unavailable - reassign any outstanding reviews"),
     ]
     availability = models.CharField(max_length=30, choices=AVAILABILITY_CHOICES)
+    reason       = models.TextField(verbose_name="Reason why reviewer is unavailable (Optional)", max_length=2048, blank=True, help_text="Provide (for the secretary's benefit) the reason why the review is unavailable", default='')
 
     def state(self):
         import datetime
diff --git a/ietf/review/resources.py b/ietf/review/resources.py
index 85e22c8b0..4ef8e8dd9 100644
--- a/ietf/review/resources.py
+++ b/ietf/review/resources.py
@@ -86,6 +86,7 @@ class UnavailablePeriodResource(ModelResource):
             "start_date": ALL,
             "end_date": ALL,
             "availability": ALL,
+	    "reason": ALL,
             "team": ALL_WITH_RELATIONS,
             "person": ALL_WITH_RELATIONS,
         }
diff --git a/ietf/templates/group/change_reviewer_settings.html b/ietf/templates/group/change_reviewer_settings.html
index e77b63ccd..cee48d9ea 100644
--- a/ietf/templates/group/change_reviewer_settings.html
+++ b/ietf/templates/group/change_reviewer_settings.html
@@ -32,12 +32,18 @@
 
   {% if unavailable_periods %}
     <table class="table">
+      <th>Period</th>
+      <th>Availability</th>
+      <th>Reason</th>
+      <th> </th>
+      <th> </th>
       {% for o in unavailable_periods %}
         <tr class="unavailable-period-{{ o.state }}">
           <td>
             {{ o.start_date|default:"indefinite" }} - {{ o.end_date|default:"indefinite" }}
           </td>
           <td>{{ o.get_availability_display }}</td>
+	  <td>{{ o.reason }}</td>
           <td>
             {% if not o.end_date %}
               <form method="post" class="form-inline" style="display:inline-block">
diff --git a/ietf/templates/review/unavailable_table.html b/ietf/templates/review/unavailable_table.html
index 79e8b4f4f..614ec7f6a 100644
--- a/ietf/templates/review/unavailable_table.html
+++ b/ietf/templates/review/unavailable_table.html
@@ -1,8 +1,14 @@
 <table class="simple-table">
+  <tr>
+    <th>Dates</th>
+    <th>Availability</th>
+    <th>Reason</th>
+  </tr>
   {% for p in unavailable_periods %}
     <tr class="unavailable-period-{{ p.state }}">
       <td> {% if p.start_date or p.end_date %}{{ p.start_date|default:"&infin;" }} -{% endif %} {{ p.end_date|default:"&infin;" }}</td>
       <td>{{ p.get_availability_display }}</td>
+      <td>{{ p.reason }}</td>
     </tr>
   {% endfor %}
 </table>