diff --git a/app/models/family.rb b/app/models/family.rb
index 6c1bc0c7b20..1871b400063 100644
--- a/app/models/family.rb
+++ b/app/models/family.rb
@@ -111,6 +111,7 @@ class Family
   index({"irs_groups.hbx_assigned_id" => 1})
 
   index({"special_enrollment_periods._id" => 1})
+  index({ "special_enrollment_periods.start_on" => 1, "special_enrollment_periods.end_on" => 1 })
 
   index({"family_members.person_id" => 1, hbx_assigned_id: 1})
 
diff --git a/spec/models/family_spec.rb b/spec/models/family_spec.rb
index 33007da8988..c0a288bca17 100644
--- a/spec/models/family_spec.rb
+++ b/spec/models/family_spec.rb
@@ -2296,4 +2296,11 @@
     Family.remove_indexes
     Family.create_indexes
   end
-end
\ No newline at end of file
+
+  it 'has the correct index on special_enrollment_periods fields' do
+    indexes = Family.index_specifications
+    expected_index = {:"special_enrollment_periods.start_on" => 1, :"special_enrollment_periods.end_on" => 1}
+
+    expect(indexes.map(&:key)).to include(expected_index)
+  end
+end