diff --git a/modules/vaos/app/services/vaos/base_service.rb b/modules/vaos/app/services/vaos/base_service.rb
index 88d9acc30d..f6e7b7a690 100644
--- a/modules/vaos/app/services/vaos/base_service.rb
+++ b/modules/vaos/app/services/vaos/base_service.rb
@@ -28,5 +28,13 @@ def referrer
         'https://review-instance.va.gov' # VAMF rejects Referer that is not valid; such as those of review instances
       end
     end
+
+    def base_vaos_route
+      if Flipper.enabled?(:va_online_scheduling_vaos_alternate_route, user)
+        'vaos-alt/v1'
+      else
+        'vaos/v1'
+      end
+    end
   end
 end
diff --git a/modules/vaos/app/services/vaos/v2/appointments_service.rb b/modules/vaos/app/services/vaos/v2/appointments_service.rb
index 80c961ec8d..c789927b35 100644
--- a/modules/vaos/app/services/vaos/v2/appointments_service.rb
+++ b/modules/vaos/app/services/vaos/v2/appointments_service.rb
@@ -727,7 +727,7 @@ def log_partial_errors(response)
       end
 
       def appointments_base_path_vaos
-        "/vaos/v1/patients/#{user.icn}/appointments"
+        "/#{base_vaos_route}/patients/#{user.icn}/appointments"
       end
 
       def appointments_base_path_vpg
@@ -742,7 +742,7 @@ def get_appointment_base_path(appointment_id)
         if Flipper.enabled?(APPOINTMENTS_USE_VPG, user)
           "/vpg/v1/patients/#{user.icn}/appointments/#{appointment_id}"
         else
-          "/vaos/v1/patients/#{user.icn}/appointments/#{appointment_id}"
+          "/#{base_vaos_route}/patients/#{user.icn}/appointments/#{appointment_id}"
         end
       end
 
@@ -773,7 +773,7 @@ def update_appointment_vpg(appt_id, status)
       end
 
       def update_appointment_vaos(appt_id, status)
-        url_path = "/vaos/v1/patients/#{user.icn}/appointments/#{appt_id}"
+        url_path = "/#{base_vaos_route}/patients/#{user.icn}/appointments/#{appt_id}"
         params = VAOS::V2::UpdateAppointmentForm.new(status:).params
         perform(:put, url_path, params, headers)
       end
diff --git a/modules/vaos/app/services/vaos/v2/mobile_facility_service.rb b/modules/vaos/app/services/vaos/v2/mobile_facility_service.rb
index db4e7f68b1..28321a84f7 100644
--- a/modules/vaos/app/services/vaos/v2/mobile_facility_service.rb
+++ b/modules/vaos/app/services/vaos/v2/mobile_facility_service.rb
@@ -285,7 +285,7 @@ def page_params(pagination_params)
       end
 
       def clinic_url(station_id)
-        "/vaos/v1/locations/#{station_id}/clinics"
+        "/#{base_vaos_route}/locations/#{station_id}/clinics"
       end
 
       def scheduling_url
diff --git a/modules/vaos/app/services/vaos/v2/patients_service.rb b/modules/vaos/app/services/vaos/v2/patients_service.rb
index e12fdc2975..7f4861efc5 100644
--- a/modules/vaos/app/services/vaos/v2/patients_service.rb
+++ b/modules/vaos/app/services/vaos/v2/patients_service.rb
@@ -29,7 +29,7 @@ def get_patient_appointment_metadata_vaos(clinic_service_id, facility_id, type)
           type:
         }
 
-        perform(:get, "/vaos/v1/patients/#{user.icn}/eligibility", params, headers)
+        perform(:get, "/#{base_vaos_route}/patients/#{user.icn}/eligibility", params, headers)
       end
 
       def get_patient_appointment_metadata_vpg(clinic_service_id, facility_id, type)
diff --git a/modules/vaos/app/services/vaos/v2/systems_service.rb b/modules/vaos/app/services/vaos/v2/systems_service.rb
index 1fd1dd9842..dc9a99e858 100644
--- a/modules/vaos/app/services/vaos/v2/systems_service.rb
+++ b/modules/vaos/app/services/vaos/v2/systems_service.rb
@@ -32,7 +32,7 @@ def get_available_slots(location_id:, clinic_id:, clinical_service:, start_dt:,
       def get_clinics(location_id:, clinical_service:, clinic_ids:, page_size:, page_number:)
         page_size = 0 if page_size.nil? # 0 is the default for the VAOS service which means return all clinics
         url = if Flipper.enabled?(:va_online_scheduling_use_vpg, user)
-                "/vpg/v1/locations/#{location_id}/clinics"
+                "/#{base_vaos_route}/v1/locations/#{location_id}/clinics"
               else
                 "/vaos/v1/locations/#{location_id}/clinics"
               end
@@ -65,7 +65,7 @@ def get_clinic_ids(ids)
       end
 
       def get_slots_vaos(location_id:, clinic_id:, start_dt:, end_dt:)
-        url_path = "/vaos/v1/locations/#{location_id}/clinics/#{clinic_id}/slots"
+        url_path = "/#{base_vaos_route}/locations/#{location_id}/clinics/#{clinic_id}/slots"
         url_params = {
           'start' => start_dt,
           'end' => end_dt