diff --git a/infotech/subjects/migrations/0002_alter_subject_year_level.py b/infotech/subjects/migrations/0002_alter_subject_year_level.py
new file mode 100644
index 0000000..9289269
--- /dev/null
+++ b/infotech/subjects/migrations/0002_alter_subject_year_level.py
@@ -0,0 +1,18 @@
+# Generated by Django 4.1.7 on 2023-03-21 13:49
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('subjects', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='subject',
+            name='year_level',
+            field=models.CharField(choices=[('IU-Y1', '1st Year'), ('IU-Y2', '2nd Year'), ('IU-Y3', '3rd Year'), ('IU-Y4', '4th Year')], max_length=20),
+        ),
+    ]
diff --git a/infotech/subjects/models.py b/infotech/subjects/models.py
index 9d96b83..0fe52a3 100644
--- a/infotech/subjects/models.py
+++ b/infotech/subjects/models.py
@@ -4,6 +4,12 @@ from django.core.validators import MaxValueValidator, MinValueValidator
 
 
 class Subject(models.Model):
+    class YearLevels(models.TextChoices):
+        FIRST_YEAR = 'IU-Y1', '1st Year'
+        SECOND_YEAR = 'IU-Y2', '2nd Year'
+        THIRD_YEAR = 'IU-Y3', '3rd Year'
+        FOURTH_YEAR = 'IU-Y4', '4th Year'
+
     name = models.CharField(max_length=40)
     enrolled_count = models.IntegerField(
         default=0,
@@ -12,7 +18,7 @@ class Subject(models.Model):
             MinValueValidator(0)
         ])
     max_slots = models.IntegerField(default=60)
-    year_level = models.CharField(max_length=20)
+    year_level = models.CharField(max_length=20, choices=YearLevels.choices)
 
     def __str__(self):
         return self.name
diff --git a/infotech/subjects/serializers.py b/infotech/subjects/serializers.py
index f730855..3970027 100644
--- a/infotech/subjects/serializers.py
+++ b/infotech/subjects/serializers.py
@@ -9,4 +9,4 @@ class SubjectSerializer(serializers.HyperlinkedModelSerializer):
     class Meta:
         model = Subject
         fields = ('id', 'name', 'enrolled_count', 'max_slots', 'year_level')
-        read_only_fields = ('id', 'max_slots')
+        read_only_fields = ('id',)