diff --git a/app/helpers/contracts_helper.rb b/app/helpers/contracts_helper.rb
index 47114af..16d0e28 100644
--- a/app/helpers/contracts_helper.rb
+++ b/app/helpers/contracts_helper.rb
@@ -111,4 +111,12 @@ module ContractsHelper
     
     options
   end
+
+  # Given a deliverable and period, validate the period
+  # TODO: could use a better name
+  def validate_period(deliverable, period)
+    if deliverable.current_date && deliverable.within_period_range?(period)
+      return period
+    end
+  end
 end
diff --git a/app/models/retainer_deliverable.rb b/app/models/retainer_deliverable.rb
index 0a675d6..8d65443 100644
--- a/app/models/retainer_deliverable.rb
+++ b/app/models/retainer_deliverable.rb
@@ -47,6 +47,17 @@ class RetainerDeliverable < HourlyDeliverable
     date_range.include?(date)
   end
 
+  # period in the format of "%Y-%m" or "%B %Y"
+  def within_period_range?(period)
+    begin
+      # both valid formats work by adding a day to the end like -01
+      date = Date.parse(period.to_s + "-01")
+      within_date_range?(date)
+    rescue ArgumentError
+      return false
+    end
+  end
+
   def months
     month_acc = []
 
diff --git a/app/views/deliverables/_details_row.html.erb b/app/views/deliverables/_details_row.html.erb
index c4d6aea..d35f604 100644
--- a/app/views/deliverables/_details_row.html.erb
+++ b/app/views/deliverables/_details_row.html.erb
@@ -1,4 +1,4 @@
-<% period ||= nil %>
+<% validated_period = validate_period(deliverable, period) %>
 
               <td colspan="11" class="deliverable_details_outer_wrapper_<%= h(deliverable.id) %>">
                 
@@ -16,7 +16,7 @@
                     <form method="get" action="<%= contract_deliverable_path(@project, contract, deliverable, :format => 'js', :as => 'deliverable_details_row') %>">
                       <fieldset>
                         <select name="period" id="retainer_period_change_<%= h(deliverable.id) %>" class="retainer_period_change">
-                          <%= retainer_period_options(deliverable, :selected => period) %>
+                          <%= retainer_period_options(deliverable, :selected => validated_period) %>
                         </select>
                       </fieldset>
                     </form>
@@ -52,28 +52,28 @@
                       <tbody>
                         <tr>
                           <td class="l"><a href="#"><strong>Labor</strong></a></td>
-                          <td class="labor_budget_spent"><%= h(format_value_field_for_contracts(deliverable.labor_budget_spent(period))) %></td>
-                          <td class="labor_budget_total"><%= h(format_value_field_for_contracts(deliverable.labor_budget_total(period))) %></td>
+                          <td class="labor_budget_spent"><%= h(format_value_field_for_contracts(deliverable.labor_budget_spent(validated_period))) %></td>
+                          <td class="labor_budget_total"><%= h(format_value_field_for_contracts(deliverable.labor_budget_total(validated_period))) %></td>
                           <td> TODO: Release 2 / TODO hrs </td>
                         </tr>
                         <tr>
                           <td class="l"><a href="#"><strong>Overhead</strong></a></td>
-                          <td class="overhead_budget_spent"><%= h(format_value_field_for_contracts(deliverable.overhead_spent(period))) %></td>
-                          <td class="overhead_budget_total"><%= h(format_value_field_for_contracts(deliverable.overhead_budget_total(period))) %></td>
+                          <td class="overhead_budget_spent"><%= h(format_value_field_for_contracts(deliverable.overhead_spent(validated_period))) %></td>
+                          <td class="overhead_budget_total"><%= h(format_value_field_for_contracts(deliverable.overhead_budget_total(validated_period))) %></td>
                           <td> TODO: Release 2 / TODO hrs </td>
                         </tr>
                         <%# TODO: Release 2, Fixed %>
                         <%# TODO: Release 2, Markup %>
                         <tr>
                           <td class="l">Profit</td>
-                          <td><%= h(format_value_field_for_contracts(deliverable.profit_left(period))) %></td>
-                          <td><%= h(format_value_field_for_contracts(deliverable.profit_budget(period))) %></td>
+                          <td><%= h(format_value_field_for_contracts(deliverable.profit_left(validated_period))) %></td>
+                          <td><%= h(format_value_field_for_contracts(deliverable.profit_budget(validated_period))) %></td>
                           <td></td>
                         </tr>
                         <tr class="total">
                           <td class="l"><strong>Total:</strong></td>
-                          <td class="total_spent"><strong><%= h(format_value_field_for_contracts(deliverable.total_spent(period))) %></strong></td>
-                          <td class="total"><strong><%= h(format_value_field_for_contracts(deliverable.total(period))) %></strong></td>
+                          <td class="total_spent"><strong><%= h(format_value_field_for_contracts(deliverable.total_spent(validated_period))) %></strong></td>
+                          <td class="total"><strong><%= h(format_value_field_for_contracts(deliverable.total(validated_period))) %></strong></td>
                           <td><strong>TODO: Release 2</strong></td>
                         </tr>
                       </tbody>
diff --git a/test/unit/helpers/contracts_helper_test.rb b/test/unit/helpers/contracts_helper_test.rb
new file mode 100644
index 0000000..92df052
--- /dev/null
+++ b/test/unit/helpers/contracts_helper_test.rb
@@ -0,0 +1,31 @@
+require 'test_helper'
+
+class ContractsHelperTest < ActionView::TestCase
+  context "#validate_period" do
+    should "with a HourlyDeliverable should return nil" do
+      assert_equal nil, validate_period(HourlyDeliverable.new, '2010-01')
+    end
+    
+    should "with a FixedDeliverable should return nil" do
+      assert_equal nil, validate_period(FixedDeliverable.new, '2010-01')
+    end
+
+    context "with a RetainerDeliverable" do
+      should "return nil when there period is not within the Deliverable's date range" do
+        retainer = RetainerDeliverable.new(:start_date => Date.new(2011,1,1),
+                                           :end_date => Date.new(2012,1,1))
+
+        assert_equal nil, validate_period(retainer, '2010-01')
+      end
+      
+      should "return the period when it's within the Deliverable's date range" do
+        retainer = RetainerDeliverable.new(:start_date => Date.new(2001,1,1),
+                                           :end_date => Date.new(2003,1,1))
+
+        assert_equal '2001-02', validate_period(retainer, '2001-02')
+      end
+    
+    end
+  end
+  
+end