diff --git a/CHANGELOG.md b/CHANGELOG.md
index 05fbcbf..5f3d18e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,12 +5,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [unreleased]
 
 ### Added
 
 - Added token-based pagination to `GET /orders`, `GET /products`,
   `GET /orders/{order_id}/statuses`, and `POST /products/{product_id}/opportunities`.
+- Optional and Extension STAPI Status Codes "scheduled", "held", "processing", "reserved", "tasked",
+  and "user_cancelled"
 
 ### Changed
 
diff --git a/src/stapi_fastapi/models/order.py b/src/stapi_fastapi/models/order.py
index 2100375..fa0d4e8 100644
--- a/src/stapi_fastapi/models/order.py
+++ b/src/stapi_fastapi/models/order.py
@@ -35,6 +35,12 @@ class OrderStatusCode(StrEnum):
     rejected = "rejected"
     completed = "completed"
     canceled = "canceled"
+    scheduled = "scheduled"
+    held = "held"
+    processing = "processing"
+    reserved = "reserved"
+    tasked = "tasked"
+    user_cancelled = "user_cancelled"
 
 
 class OrderStatus(BaseModel):