diff --git a/config/features.yml b/config/features.yml
index 52b070a5f50..46f59132728 100644
--- a/config/features.yml
+++ b/config/features.yml
@@ -192,6 +192,9 @@ features:
   champva_pdf_decrypt:
     actor_type: user
     description: Enables unlocking password protected file submissions in IVC CHAMPVA forms.
+  champva_require_all_s3_success:
+    actor_type: user
+    description: Enables raising a StandardError if any supporting documents fail to upload to S3 in IVC CHAMPVA forms.
   check_in_experience_enabled:
     actor_type: user
     description: Enables the health care check-in experiences
diff --git a/modules/ivc_champva/app/services/ivc_champva/file_uploader.rb b/modules/ivc_champva/app/services/ivc_champva/file_uploader.rb
index b390e088d8d..4187435dda5 100644
--- a/modules/ivc_champva/app/services/ivc_champva/file_uploader.rb
+++ b/modules/ivc_champva/app/services/ivc_champva/file_uploader.rb
@@ -27,18 +27,12 @@ def initialize(form_id, metadata, file_paths, insert_db_row = false) # rubocop:d
     #
     # The return value reflects whether or not all files were successfully uploaded.
     #
-    # If successful, it will return:
-    # - An array containing a single HTTP status code and an optional error message,
-    #   e.g. [200] | [400, 'No such file']
-    #
-    # If any uploads yield non-200 statuses when submitted to S3, it will return:
-    # - An array of arrays of statuses and optional error messages corresponding to the individual
-    #   uploads.
-    #   E.g., for two documents uploaded, one successful and one failed, it returns:
-    #   [[200], [400, 'No such file or directory']]
-    #
-    # @return [Array<Integer, String>, Array<Array<Integer, String>>] Either an array of arrays, or
-    # an array with a status code and an optional error message string.
+    # If successful, it will return an array containing a single HTTP status code and an
+    # optional error message, e.g. [200] | [400, 'No such file']
+    #
+    # If any uploads yield non-200 statuses when submitted to S3, it raise a StandardError.
+    #
+    # @return [Array<Integer, String>] An array with a status code and an optional error message string.
     def handle_uploads
       results = @metadata['attachment_ids'].zip(@file_paths).map do |attachment_id, file_path|
         next if file_path.blank?
@@ -50,11 +44,21 @@ def handle_uploads
         response_status
       end.compact
 
-      all_success = results.all? { |(status, _)| status == 200 }
+      s3_err = nil
+      all_success = results.all? do |(status, err)|
+        s3_err = err if err # Collect last error present for logging purposes
+        status == 200
+      end
 
       if all_success
         generate_and_upload_meta_json
+      elsif Flipper.enabled?(:champva_require_all_s3_success, @current_user)
+        monitor.track_s3_upload_error(@metadata['uuid'], s3_err)
+        # Stop this submission in its tracks - entries will still be added to database
+        # for these files, but user will see error on the FE saying submission failed.
+        raise StandardError, "IVC ChampVa Forms - failed to upload all documents for submission: #{s3_err}"
       else
+        # array of arrays, e.g.: [[200], [400, 'S3 error']]
         results
       end
     end
diff --git a/modules/ivc_champva/lib/ivc_champva/monitor.rb b/modules/ivc_champva/lib/ivc_champva/monitor.rb
index e707e21090f..a0c62b262dc 100644
--- a/modules/ivc_champva/lib/ivc_champva/monitor.rb
+++ b/modules/ivc_champva/lib/ivc_champva/monitor.rb
@@ -62,5 +62,17 @@ def track_failed_send_zsf_notification_to_pega(form_uuid, template_id)
                     "#{STATS_KEY}.failed_send_zsf_notification_to_pega",
                     call_location: caller_locations.first, **additional_context)
     end
+
+    ##
+    # Logs UUID and S3 error message when supporting docs fail to reach S3.
+    #
+    # @param [String] form_uuid UUID of the form submission with failed uploads
+    # @param [String] s3_err Error message received from a failed upload to S3
+    def track_s3_upload_error(form_uuid, s3_err)
+      additional_context = { form_uuid:, s3_err: }
+      track_request('warn', "IVC ChampVa Forms - failed to upload all documents for submission: #{form_uuid}",
+                    "#{STATS_KEY}.s3_upload_error",
+                    call_location: caller_locations.first, **additional_context)
+    end
   end
 end
diff --git a/modules/ivc_champva/spec/services/file_uploader_spec.rb b/modules/ivc_champva/spec/services/file_uploader_spec.rb
index 87f947520f2..e62c39577b6 100644
--- a/modules/ivc_champva/spec/services/file_uploader_spec.rb
+++ b/modules/ivc_champva/spec/services/file_uploader_spec.rb
@@ -24,9 +24,24 @@
       end
     end
 
-    context 'when at least one PDF upload fails' do
+    context 'when at least one PDF upload fails and champva_require_all_s3_success flipper is enabled:' do
       before do
         allow(uploader).to receive(:upload).and_return([400, 'Upload failed'])
+        allow(Flipper).to receive(:enabled?).with(:champva_require_all_s3_success, @current_user).and_return(true)
+      end
+
+      it 'raises an error' do
+        # Updated this test to account for new error being raised. This is so submissions are blocked
+        # from completing if any files fail to make it to S3. Formerly, the expectation was:
+        # `expect(uploader.handle_uploads).to eq([[400, 'Upload failed'], [400, 'Upload failed']])`
+        expect { uploader.handle_uploads }.to raise_error(StandardError, /Upload failed/)
+      end
+    end
+
+    context 'when at least one PDF upload fails and champva_require_all_s3_success flipper is disabled:' do
+      before do
+        allow(uploader).to receive(:upload).and_return([400, 'Upload failed'])
+        allow(Flipper).to receive(:enabled?).with(:champva_require_all_s3_success, @current_user).and_return(false)
       end
 
       it 'returns an array of upload results' do