diff --git a/main.py b/main.py
index da78285..bb32949 100755
--- a/main.py
+++ b/main.py
@@ -49,6 +49,12 @@ def main():
         default="out",
     )
 
+    parser.add_argument(
+        "--output-passwd",
+        action="store_true",
+        help="Output passwd and group files instead of JSON records. This still applies any filtering and transformations.",
+    )
+
     parser.add_argument(
         "-e",
         "--email-domain",
@@ -80,25 +86,25 @@ def main():
         "--set-default-umask",
         type=str,
         help="Set the umask for all users.",
-        metavar='OCTAL',
+        metavar="OCTAL",
     )
     parser.add_argument(
         "--set-default-mount-no-devices",
         type=bool,
         help="Set mountNoDevices for all users.",
-        metavar='BOOL',
+        metavar="BOOL",
     )
     parser.add_argument(
         "--set-default-mount-no-suid",
         type=bool,
         help="Set mountNoSuid for all users.",
-        metavar='BOOL',
+        metavar="BOOL",
     )
     parser.add_argument(
         "--set-default-mount-no-execute",
         type=bool,
         help="Set mountNoExecute for all users.",
-        metavar='BOOL',
+        metavar="BOOL",
     )
 
     args = parser.parse_args()
@@ -126,7 +132,10 @@ def main():
         if user.name in shadow:
             user.set_shadow_entry(shadow[user.name])
 
-    output_to_directory(users, groups, args.output_dir)
+    if args.output_passwd:
+        generate_passwd_and_group_files(users, groups, args.output_dir)
+    else:
+        output_to_directory(users, groups, args.output_dir)
 
 
 def ensure_no_overlapping_uids(users: dict[str, User]):
@@ -496,5 +505,46 @@ def output_to_directory(
                     json.dump({}, f)
 
 
+def generate_passwd_and_group_files(
+    users: dict[str, User],
+    groups: dict[str, Group],
+    output_dir: Path,
+):
+    if not output_dir.exists():
+        output_dir.mkdir(parents=True)
+
+    passwd_path = output_dir / "passwd"
+    group_path = output_dir / "group"
+
+    users_ = list(users.values())
+    users_.sort(key=lambda u: u.uid)
+
+    groups_ = list(groups.values())
+    groups_.sort(key=lambda g: g.gid)
+
+    with passwd_path.open("w") as passwd_file:
+        for user in users_:
+            gecos = ",".join(
+                filter(
+                    None,
+                    [
+                        user.full_name,
+                        user.location,
+                        user.work_phone,
+                        user.home_phone,
+                        user.other,
+                    ],
+                )
+            )
+            passwd_file.write(
+                f"{user.name}:{user.password if user.password else 'x'}:{user.uid}:{user.gid}:{gecos}:{user.home}:{user.shell}\n"
+            )
+
+    with group_path.open("w") as group_file:
+        for group in groups_:
+            members_str = ",".join(group.members)
+            group_file.write(f"{group.name}:x:{group.gid}:{members_str}\n")
+
+
 if __name__ == "__main__":
     main()