diff --git a/modules/ivc_champva/app/controllers/ivc_champva/v1/uploads_controller.rb b/modules/ivc_champva/app/controllers/ivc_champva/v1/uploads_controller.rb
index fbc5a31a77f..e2732a66ce6 100644
--- a/modules/ivc_champva/app/controllers/ivc_champva/v1/uploads_controller.rb
+++ b/modules/ivc_champva/app/controllers/ivc_champva/v1/uploads_controller.rb
@@ -89,8 +89,22 @@ def get_attachment_ids_and_form(parsed_form_data)
       end
 
       def supporting_document_ids(parsed_form_data)
-        parsed_form_data['supporting_docs']&.pluck('attachment_id')&.compact.presence ||
-          parsed_form_data['supporting_docs']&.pluck('claim_id')&.compact.presence || []
+        cached_uploads = []
+        parsed_form_data['supporting_docs']&.each do |d|
+          # Get the database record that corresponds to this file upload:
+          record = PersistentAttachments::MilitaryRecords.find_by(guid: d['confirmation_code'])
+          # Push to our array with some extra information so we can sort by date uploaded:
+          cached_uploads.push({ attachment_id: d['attachment_id'],
+                                created_at: record.created_at,
+                                file_name: record.file.id })
+        end
+
+        # Sort by date created so we have the file's upload order and
+        # reduce down to just the attachment id strings:
+        attachment_ids = cached_uploads.sort_by { |h| h[:created_at] }.pluck(:attachment_id)&.compact.presence
+
+        # Return either the attachment IDs or `claim_id`s (in the case of form 10-7959a):
+        attachment_ids || parsed_form_data['supporting_docs']&.pluck('claim_id')&.compact.presence || []
       end
 
       # rubocop:disable Metrics/MethodLength
diff --git a/modules/ivc_champva/spec/requests/ivc_champva/v1/forms/uploads_spec.rb b/modules/ivc_champva/spec/requests/ivc_champva/v1/forms/uploads_spec.rb
index c8db6b456e4..5f7b9cd9c76 100644
--- a/modules/ivc_champva/spec/requests/ivc_champva/v1/forms/uploads_spec.rb
+++ b/modules/ivc_champva/spec/requests/ivc_champva/v1/forms/uploads_spec.rb
@@ -36,6 +36,8 @@
 
       it 'uploads a PDF file to S3' do
         mock_form = double(first_name: 'Veteran', last_name: 'Surname', form_uuid: 'some_uuid')
+        allow(PersistentAttachments::MilitaryRecords).to receive(:find_by)
+          .and_return(double('Record1', created_at: 1.day.ago, id: 'some_uuid', file: double(id: 'file0')))
         allow(IvcChampvaForm).to receive(:first).and_return(mock_form)
         allow_any_instance_of(Aws::S3::Client).to receive(:put_object).and_return(true)
 
@@ -49,6 +51,17 @@
 
         expect(response).to have_http_status(:ok)
       end
+
+      it 'returns a 500 error when supporting documents are submitted, but are missing from the database' do
+        allow_any_instance_of(Aws::S3::Client).to receive(:put_object).and_return(true)
+
+        # Actual supporting_docs should exist as records in the DB. This test
+        # ensures that if they aren't present we won't have a silent failure
+        data_with_docs = data.merge({ supporting_docs: [{ confirmation_code: 'NOT_IN_DATABASE' }] })
+        post '/ivc_champva/v1/forms', params: data_with_docs
+
+        expect(response).to have_http_status(:internal_server_error)
+      end
     end
   end
 
@@ -123,6 +136,53 @@
       result = controller.supporting_document_ids
       expect(result).to eq([1, 2])
     end
+
+    it 'orders supporting document ids by date created' do
+      clamscan = double(safe?: true)
+      allow(Common::VirusScan).to receive(:scan).and_return(clamscan)
+
+      # Mocking PersistentAttachments::MilitaryRecords to return controlled data
+      record1 = double('Record1', created_at: 1.day.ago, id: 'doc0', file: double(id: 'file0'))
+      record2 = double('Record2', created_at: Time.zone.now, id: 'doc1', file: double(id: 'file1'))
+
+      allow(PersistentAttachments::MilitaryRecords).to receive(:find_by).with(guid: 'code1').and_return(record1)
+      allow(PersistentAttachments::MilitaryRecords).to receive(:find_by).with(guid: 'code2').and_return(record2)
+
+      parsed_form_data = {
+        'form_number' => '10-10D',
+        'supporting_docs' => [
+          { 'attachment_id' => 'doc1', 'confirmation_code' => 'code2' },
+          { 'attachment_id' => 'doc0', 'confirmation_code' => 'code1' }
+        ]
+      }
+
+      # Create an instance of the controller
+      controller = IvcChampva::V1::UploadsController.new
+
+      # Call the private method using `send`
+      attachment_ids = controller.send(:supporting_document_ids, parsed_form_data)
+
+      # Mock metadata generation to align with the sorted order
+      metadata = { 'metadata' => {}, 'attachment_ids' => attachment_ids }
+
+      expect(metadata).to eq({
+                               'metadata' => {},
+                               'attachment_ids' => %w[doc0 doc1] # Ensure this matches the sorted order
+                             })
+    end
+
+    it 'throws an error when no matching supporting doc is present in the database' do
+      controller = IvcChampva::V1::UploadsController.new
+      parsed_form_data = {
+        'form_number' => '10-10D',
+        'supporting_docs' => [
+          { 'attachment_id' => 'doc0', 'confirmation_code' => 'NOT_IN_DATABASE' }
+        ]
+      }
+      expect do
+        controller.send(:supporting_document_ids, parsed_form_data)
+      end.to raise_error(NoMethodError)
+    end
   end
 
   describe '#get_file_paths_and_metadata' do