diff --git a/app/routes/admin.py b/app/routes/admin.py
index a4112ac..4fae949 100644
--- a/app/routes/admin.py
+++ b/app/routes/admin.py
@@ -37,3 +37,151 @@ def manual_credit_refill() -> dict:
     return scheduler_service.trigger_credit_refill_now()
 
 
+@bp.route("/users")
+@require_auth
+@require_role("admin")
+def list_users() -> dict:
+    """List all users (admin only)."""
+    from app.models.user import User
+    
+    users = User.query.order_by(User.created_at.desc()).all()
+    return {
+        "users": [user.to_dict() for user in users],
+        "total": len(users)
+    }
+
+
+@bp.route("/users/<int:user_id>", methods=["PATCH"])
+@require_auth
+@require_role("admin")
+def update_user(user_id: int) -> dict:
+    """Update user information (admin only)."""
+    from flask import request
+    from app.database import db
+    from app.models.user import User
+    from app.models.plan import Plan
+    
+    data = request.get_json()
+    if not data:
+        return {"error": "No data provided"}, 400
+    
+    user = User.query.get(user_id)
+    if not user:
+        return {"error": "User not found"}, 404
+    
+    # Validate and update fields
+    try:
+        if "name" in data:
+            name = data["name"].strip()
+            if not name:
+                return {"error": "Name cannot be empty"}, 400
+            if len(name) > 100:
+                return {"error": "Name too long (max 100 characters)"}, 400
+            user.name = name
+        
+        if "credits" in data:
+            credits = data["credits"]
+            if not isinstance(credits, int) or credits < 0:
+                return {"error": "Credits must be a non-negative integer"}, 400
+            user.credits = credits
+        
+        if "plan_id" in data:
+            plan_id = data["plan_id"]
+            if not isinstance(plan_id, int):
+                return {"error": "Plan ID must be an integer"}, 400
+            
+            plan = Plan.query.get(plan_id)
+            if not plan:
+                return {"error": "Plan not found"}, 404
+            
+            user.plan_id = plan_id
+        
+        if "is_active" in data:
+            is_active = data["is_active"]
+            if not isinstance(is_active, bool):
+                return {"error": "is_active must be a boolean"}, 400
+            user.is_active = is_active
+        
+        db.session.commit()
+        
+        return {
+            "message": "User updated successfully",
+            "user": user.to_dict()
+        }
+        
+    except Exception as e:
+        db.session.rollback()
+        return {"error": f"Failed to update user: {str(e)}"}, 500
+
+
+@bp.route("/users/<int:user_id>/deactivate", methods=["POST"])
+@require_auth
+@require_role("admin")
+def deactivate_user(user_id: int) -> dict:
+    """Deactivate a user (admin only)."""
+    from app.database import db
+    from app.models.user import User
+    
+    user = User.query.get(user_id)
+    if not user:
+        return {"error": "User not found"}, 404
+    
+    # Prevent admin from deactivating themselves
+    current_user = get_current_user()
+    if str(user.id) == current_user["id"]:
+        return {"error": "Cannot deactivate your own account"}, 400
+    
+    try:
+        user.deactivate()
+        db.session.commit()
+        
+        return {
+            "message": "User deactivated successfully",
+            "user": user.to_dict()
+        }
+        
+    except Exception as e:
+        db.session.rollback()
+        return {"error": f"Failed to deactivate user: {str(e)}"}, 500
+
+
+@bp.route("/users/<int:user_id>/activate", methods=["POST"])
+@require_auth
+@require_role("admin")
+def activate_user(user_id: int) -> dict:
+    """Activate a user (admin only)."""
+    from app.database import db
+    from app.models.user import User
+    
+    user = User.query.get(user_id)
+    if not user:
+        return {"error": "User not found"}, 404
+    
+    try:
+        user.activate()
+        db.session.commit()
+        
+        return {
+            "message": "User activated successfully",
+            "user": user.to_dict()
+        }
+        
+    except Exception as e:
+        db.session.rollback()
+        return {"error": f"Failed to activate user: {str(e)}"}, 500
+
+
+@bp.route("/plans")
+@require_auth
+@require_role("admin")
+def list_plans() -> dict:
+    """List all available plans (admin only)."""
+    from app.models.plan import Plan
+    
+    plans = Plan.query.order_by(Plan.id).all()
+    return {
+        "plans": [plan.to_dict() for plan in plans],
+        "total": len(plans)
+    }
+
+