diff --git a/cli/src/core/service_creator.py b/cli/src/core/service_creator.py
index c1975b2..9602792 100644
--- a/cli/src/core/service_creator.py
+++ b/cli/src/core/service_creator.py
@@ -1,4 +1,5 @@
 import logging
+import re
 import shutil
 import subprocess
 from pathlib import Path
@@ -22,6 +23,9 @@ REPO_ROOT = get_git_root(__file__)
 SERVICE_TEMPLATES_DIR = REPO_ROOT / "templates" / "service"
 SERVICE_DEST_DIR = REPO_ROOT / "services"
 
+MASTER_SERVICE_DIR = REPO_ROOT / "services" / "000-master" / "current"
+MASTER_IOC_SUBS_FILE = MASTER_SERVICE_DIR / "ioc" / "AGEBD-CPCL-MASTER_main.subs"
+
 # TODO: lots of hardcoded paths. Create config object?
 
 
@@ -64,6 +68,12 @@ class ServiceCreator:
             registry.write_to_config()
             hla_names.write_to_config()
 
+            self._append_to_master_ioc_subs(
+                service_name=service.name_upper,
+                starton="1",
+                autooff="0",
+            )
+
             # TODO: can't push if branch already exists in remote
             git_push_changes(
                 repo=repo,
@@ -134,3 +144,32 @@ class ServiceCreator:
             logger.error(f"Exit Code: {e.returncode}")
             logger.error(f"Details:\n{e.stderr}")
             raise UVError(e.stderr) from e
+
+    def _append_to_master_ioc_subs(
+        self,
+        service_name: str,
+        starton: str = "0",
+        autooff: str = "0",
+    ) -> str:
+        """
+        Parses the configuration text and appends a new row before the closing bracket.
+        """
+        with open(MASTER_IOC_SUBS_FILE) as f:
+            file_content = f.read()
+
+        new_row = f'          {{ "{{{{ agebd_env }}}}" ,     "{service_name:<20}" , "{starton}",     "{autooff}"     }}'
+
+        # Use regex to find the last closing curly brace of the configuration block
+        # This targets the line that contains only a lone closing brace, optional spaces, and maybe a comma/semicolon.
+        pattern = r"(\s*\n\s*\}(?:;|,)?\s*$)"
+
+        if re.search(pattern, file_content, re.MULTILINE):
+            # Insert our new row right before that closing brace line
+            updated_content = re.sub(
+                pattern, f"\n{new_row}\n\\1", file_content, count=1, flags=re.MULTILINE
+            )
+            return updated_content
+        else:
+            raise ValueError(
+                "Could not locate the closing structure format '}' inside the configuration."
+            )