diff --git a/apps/course/models/course.py b/apps/course/models/course.py
index 79a7a42..7fa1fd1 100644
--- a/apps/course/models/course.py
+++ b/apps/course/models/course.py
@@ -119,7 +119,16 @@ class Course(models.Model):
         if not self.slug:
             self.slug = generate_slug_for_model(Course, self.title)
 
-        if self.discount_percentage > 0:
+        # Ensure consistency: if price is 0, set is_free to True and discount_percentage to 0
+        if self.price == 0:
+            self.is_free = True
+            self.discount_percentage = 0
+            self.final_price = Decimal('0.00')
+        elif self.is_free:
+            self.price = Decimal('0.00')
+            self.discount_percentage = 0
+            self.final_price = Decimal('0.00')
+        elif self.discount_percentage > 0:
             discount_amount = (self.price * self.discount_percentage) / 100
             final_price = self.price - discount_amount
             self.final_price = Decimal(math.ceil(final_price)).quantize(Decimal('0.00'))
diff --git a/apps/course/serializers/course.py b/apps/course/serializers/course.py
index 5361182..09d5308 100644
--- a/apps/course/serializers/course.py
+++ b/apps/course/serializers/course.py
@@ -24,9 +24,9 @@ class CourseListSerializer(serializers.ModelSerializer):
     thumbnail = serializers.SerializerMethodField()
     participant_count = serializers.SerializerMethodField()
     lessons_count = serializers.SerializerMethodField()
-    # price = serializers.SerializerMethodField()
-    # discount_percentage = serializers.SerializerMethodField()
-    # final_price = serializers.SerializerMethodField()
+    price = serializers.SerializerMethodField()
+    discount_percentage = serializers.SerializerMethodField()
+    final_price = serializers.SerializerMethodField()
     
     class Meta:
         model = Course        
@@ -61,15 +61,17 @@ class CourseListSerializer(serializers.ModelSerializer):
         return max(lessons_count, obj.lessons_count)
         
     def get_price(self, obj):
-        if obj.is_free:
+        if obj.is_free or obj.price == 0:
             return "0.00"
         return str(obj.price)
         
     def get_discount_percentage(self, obj):
-        return 0 if obj.is_free else obj.discount_percentage
+        if obj.is_free or obj.price == 0:
+            return 0
+        return obj.discount_percentage
         
     def get_final_price(self, obj):
-        if obj.is_free:
+        if obj.is_free or obj.price == 0:
             return "0.00"
         return str(obj.final_price)
     
@@ -217,15 +219,17 @@ class CourseDetailSerializer(serializers.ModelSerializer):
         return obj.participants.count()
         
     def get_price(self, obj):
-        if obj.is_free:
+        if obj.is_free or obj.price == 0:
             return "0.00"
         return str(obj.price)
         
     def get_discount_percentage(self, obj):
-        return 0 if obj.is_free else obj.discount_percentage
+        if obj.is_free or obj.price == 0:
+            return 0
+        return obj.discount_percentage
         
     def get_final_price(self, obj):
-        if obj.is_free:
+        if obj.is_free or obj.price == 0:
             return "0.00"
         return str(obj.final_price)