diff --git a/openapi_first/templates/vet_app/data.py b/openapi_first/templates/vet_app/data.py
index bd6349f..593ce96 100644
--- a/openapi_first/templates/vet_app/data.py
+++ b/openapi_first/templates/vet_app/data.py
@@ -22,6 +22,7 @@ from models import (
     Parent, ParentCreate,
     Vet, VetCreate,
     Treatment, TreatmentCreate,
+    Procedure, ProcedureNotes,
     Pet, PetCreate,
     Appointment, AppointmentCreate,
 )
@@ -158,6 +159,7 @@ def create_treatment(payload: TreatmentCreate) -> Treatment:
         id=_treatments_next_id,
         label=payload.label,
         description=payload.description,
+        procedures=payload.procedures,
         metadata={"createdOn": now, "updatedOn": now} if payload.metadata else None,
     )
     _treatments[_treatments_next_id] = treatment
@@ -174,6 +176,7 @@ def update_treatment(treatment_id: int, payload: TreatmentCreate) -> Treatment:
         id=treatment_id,
         label=payload.label,
         description=payload.description if payload.description is not None else current.description,
+        procedures=payload.procedures,
         metadata={"createdOn": current.metadata["createdOn"] if current.metadata else None, "updatedOn": now},
     )
     _treatments[treatment_id] = updated
@@ -321,11 +324,21 @@ def _seed_data():
     _vets[3] = Vet(id=3, name="Emily Davis", specialty="General Practice", email="emily@clinic.com", phone="555-0203", metadata=meta)
     _vets_next_id = 4
 
-    _treatments[1] = Treatment(id=1, label="Annual Checkup", description="Full physical examination", metadata=meta)
-    _treatments[2] = Treatment(id=2, label="Vaccination", description="Core vaccines for common diseases", metadata=meta)
-    _treatments[3] = Treatment(id=3, label="Dental Cleaning", description="Scaling, polishing, and oral exam", metadata=meta)
-    _treatments[4] = Treatment(id=4, label="Spay/Neuter", description="Surgical sterilization", metadata=meta)
-    _treatments[5] = Treatment(id=5, label="Blood Panel", description="Complete blood count and chemistry", metadata=meta)
+    _treatments[1] = Treatment(id=1, label="Annual Checkup", description="Full physical examination",
+        procedures=[Procedure(name="Physical Exam", cost=50.0), Procedure(name="Heart Rate", notes=ProcedureNotes(summary="Normal rhythm"))],
+        metadata=meta)
+    _treatments[2] = Treatment(id=2, label="Vaccination", description="Core vaccines for common diseases",
+        procedures=[Procedure(name="DHPP Vaccine", cost=35.0), Procedure(name="Rabies Vaccine", cost=45.0)],
+        metadata=meta)
+    _treatments[3] = Treatment(id=3, label="Dental Cleaning", description="Scaling, polishing, and oral exam",
+        procedures=[Procedure(name="Scaling", cost=80.0), Procedure(name="Polishing", cost=40.0, notes=ProcedureNotes(summary="High-speed polish"))],
+        metadata=meta)
+    _treatments[4] = Treatment(id=4, label="Spay/Neuter", description="Surgical sterilization",
+        procedures=[Procedure(name="Pre-op Exam", cost=30.0), Procedure(name="Surgery", cost=200.0), Procedure(name="Post-op Care", cost=50.0)],
+        metadata=meta)
+    _treatments[5] = Treatment(id=5, label="Blood Panel", description="Complete blood count and chemistry",
+        procedures=[Procedure(name="CBC", cost=25.0), Procedure(name="Chemistry Panel", cost=60.0, notes=ProcedureNotes(summary="Fasting required"))],
+        metadata=meta)
     _treatments_next_id = 6
 
     _pets[1] = Pet(id=1, name="Max", species="dog", age=4, weight=25.5, birthDate=date(2022, 3, 15), parents=[_parents[1]], metadata=meta)
diff --git a/openapi_first/templates/vet_app/models.py b/openapi_first/templates/vet_app/models.py
index bcaeb25..2895a82 100644
--- a/openapi_first/templates/vet_app/models.py
+++ b/openapi_first/templates/vet_app/models.py
@@ -38,9 +38,22 @@ class Vet(VetBase):
     id: int
 
 
+class ProcedureNotes(BaseModel):
+    summary: str | None = None
+    details: str | None = None
+
+
+class Procedure(BaseModel):
+    name: str | None = None
+    description: str | None = None
+    cost: float | None = None
+    notes: ProcedureNotes | None = None
+
+
 class TreatmentBase(BaseModel):
     label: str
     description: str | None = None
+    procedures: list[Procedure] = []
     metadata: Metadata | None = None
 
 
diff --git a/openapi_first/templates/vet_app/openapi.yaml b/openapi_first/templates/vet_app/openapi.yaml
index e8557f0..11675f4 100644
--- a/openapi_first/templates/vet_app/openapi.yaml
+++ b/openapi_first/templates/vet_app/openapi.yaml
@@ -23,6 +23,41 @@ components:
           type: string
           format: date-time
 
+    Procedure:
+      type: object
+      x-display-format: "{name} — ${cost}"
+      properties:
+        name:
+          type: string
+          x-order: 1
+          x-label: "Procedure Name"
+        description:
+          type: string
+          x-order: 2
+          x-label: "Description"
+        cost:
+          type: number
+          format: float
+          x-order: 3
+          x-label: "Cost"
+        notes:
+          $ref: '#/components/schemas/ProcedureNotes'
+          x-order: 4
+          x-label: "Notes"
+
+    ProcedureNotes:
+      type: object
+      x-display-format: "{summary}"
+      properties:
+        summary:
+          type: string
+          x-order: 1
+          x-label: "Summary"
+        details:
+          type: string
+          x-order: 2
+          x-label: "Details"
+
     Parent:
       type: object
       x-resource: parents
@@ -131,6 +166,13 @@ components:
           x-order: 2
           x-label: "Description"
           x-description: "Detailed description of the treatment"
+        procedures:
+          type: array
+          items:
+            $ref: '#/components/schemas/Procedure'
+          x-order: 3
+          x-label: "Procedures"
+          x-description: "List of procedures performed during this treatment"
         metadata:
           $ref: '#/components/schemas/Metadata'
           x-order: 4