diff --git a/cmd/main-migration/migrations/20251209022744.sql b/cmd/main-migration/migrations/20251209022744.sql
new file mode 100644
index 00000000..a8a18481
--- /dev/null
+++ b/cmd/main-migration/migrations/20251209022744.sql
@@ -0,0 +1,2 @@
+-- Modify "ChemoPlan" table
+ALTER TABLE "public"."ChemoPlan" ADD COLUMN "Encounter_Id" bigint NULL, ADD CONSTRAINT "fk_ChemoPlan_Encounter" FOREIGN KEY ("Encounter_Id") REFERENCES "public"."Encounter" ("Id") ON UPDATE NO ACTION ON DELETE NO ACTION;
diff --git a/cmd/main-migration/migrations/20251209025908.sql b/cmd/main-migration/migrations/20251209025908.sql
new file mode 100644
index 00000000..5a8522d7
--- /dev/null
+++ b/cmd/main-migration/migrations/20251209025908.sql
@@ -0,0 +1,2 @@
+-- Modify "Chemo" table
+ALTER TABLE "public"."Chemo" ADD COLUMN "Class_Code" text NULL;
diff --git a/cmd/main-migration/migrations/atlas.sum b/cmd/main-migration/migrations/atlas.sum
index 3880e01e..ac03c936 100644
--- a/cmd/main-migration/migrations/atlas.sum
+++ b/cmd/main-migration/migrations/atlas.sum
@@ -1,4 +1,4 @@
-h1:o4jOACV/QY64oiqrbnZvGei0J65px0JBwAXakl8h+Oc=
+h1:SSn9Za93bvbyBNVuGwpy9R/E/+1hm802NevovuLsplc=
 20250904105930.sql h1:MEM6blCgke9DzWQSTnLzasbPIrcHssNNrJqZpSkEo6k=
 20250904141448.sql h1:J8cmYNk4ZrG9fhfbi2Z1IWz7YkfvhFqTzrLFo58BPY0=
 20250908062237.sql h1:Pu23yEW/aKkwozHoOuROvHS/GK4ngARJGdO7FB7HZuI=
@@ -145,10 +145,12 @@ h1:o4jOACV/QY64oiqrbnZvGei0J65px0JBwAXakl8h+Oc=
 20251202180207.sql h1:IHmSMIO3ia+YV5GULixbdlV1joaUAWtnjQHPd8+HKiM=
 20251202231005.sql h1:lua0KKoeBptSfs/6ehZE6Azo6YUlNkOJwGFyb1HQWkY=
 20251203205052.sql h1:nk0VK2Uv4bHE3SBfHo/aevVZxtHzr7zAzvmMU8TCCtk=
-20251207020537.sql h1:uqqIQaBoZGoOXVQKkalNXwF2awcA+rhjNVevWEzIIok=
-20251207212015.sql h1:muRdWqRKfJQFMfezj2B4n0E6bbjIz1GrzHEyhoxy2mk=
-20251207221222.sql h1:+mU/25n3hQLRU6MK8B+Uwzl9YBRezX3xWDtIKnweN78=
-20251205073858.sql h1:Ep03jQ9hJAJILDJfKVcmi3Z6fqmTHSq9gKQtwf070PE=
-20251205211957.sql h1:zRHcvLY+nfLdUyMcfpgI8vYQcPzJUWbfjkc4cK0QGHU=
-20251205214433.sql h1:tgHB/fNy9XwAOWIqNI6GCqGXeJgSuZs2aHiCEj3BHZA=
-20251205221124.sql h1:VthPlq3XcQOYz5VsFivb4Wof8jCAG36fAaerKmM4/OA=
+20251205073858.sql h1:46qqXnArgJmzGE/WO7v7Ev8Jh7BudDiGbdANexq/5Dk=
+20251205211957.sql h1:3fvtZ/mBWsTIXllXMFOuCLJsp4MivVP56dunehlU0yo=
+20251205214433.sql h1:rn3++FEfX7ntcJcOmCEuOMnr27TZqH0KMGRppzFwFTc=
+20251205221124.sql h1:CRruUvGZqlVDBmbQSVEl4wFm+uq30AurMMDI6sb8jxg=
+20251207020537.sql h1:JspoBMoP1Yk854vtNniepvATINUpODQ9idKiMkNL0OU=
+20251207212015.sql h1:pEH0+QnQ5WXNizxcToLk+8XYaAb6q6WJ1/MJViRVtNQ=
+20251207221222.sql h1:gpl3V4/3AGqO3WLCpWW2GAtwuhpmNuBqXMiP61wVHX0=
+20251209022744.sql h1:0WXCKpMDFAe/aVnosMGmCYp3mw+FIu+foX14sYmq750=
+20251209025908.sql h1:MgO50it1hj7Jj8BD5yKjW8OLC9qS3FFEdelqIsLT1v8=
diff --git a/internal/domain/main-entities/chemo-plan/entity.go b/internal/domain/main-entities/chemo-plan/entity.go
index 6bb156b3..2dc5a363 100644
--- a/internal/domain/main-entities/chemo-plan/entity.go
+++ b/internal/domain/main-entities/chemo-plan/entity.go
@@ -1,6 +1,7 @@
 package chemo_plan
 
 import (
+	ee "simrs-vx/internal/domain/main-entities/encounter"
 	"time"
 
 	ecore "simrs-vx/internal/domain/base-entities/core"
@@ -10,12 +11,14 @@ import (
 
 type ChemoPlan struct {
 	ecore.Main
-	Parent_Id       *uint                    `json:"parent_id"` // chemo.Id
-	Protocol_Id     *uint                    `json:"protocol_id"`
-	SeriesNumber    *uint16                  `json:"seriesNumber"` // series ke -
-	CycleNumber     *uint                    `json:"cycleNumber"`  // cycle ke -
-	PlanDate        *time.Time               `json:"planDate"`
-	RealizationDate *time.Time               `json:"realizationDate"`
-	Notes           *string                  `json:"notes"`
-	Status          *ere.StatusProtocolChemo `json:"status"`
+	Parent_Id       *uint                   `json:"parent_id"` // chemo.Id
+	Protocol_Id     *uint                   `json:"protocol_id"`
+	SeriesNumber    *uint16                 `json:"seriesNumber"` // series ke -
+	CycleNumber     *uint                   `json:"cycleNumber"`  // cycle ke -
+	PlanDate        *time.Time              `json:"planDate"`
+	RealizationDate *time.Time              `json:"realizationDate"`
+	Notes           *string                 `json:"notes"`
+	Status          ere.StatusProtocolChemo `json:"status"`
+	Encounter_Id    *uint                   `json:"encounter_id"`
+	Encounter       *ee.Encounter           `json:"encounter,omitempty" gorm:"foreignKey:Encounter_Id;references:Id"`
 }
diff --git a/internal/domain/main-entities/chemo/entity.go b/internal/domain/main-entities/chemo/entity.go
index 682333ed..cc828835 100644
--- a/internal/domain/main-entities/chemo/entity.go
+++ b/internal/domain/main-entities/chemo/entity.go
@@ -1,6 +1,7 @@
 package chemo
 
 import (
+	ere "simrs-vx/internal/domain/references/encounter"
 	"time"
 
 	ecore "simrs-vx/internal/domain/base-entities/core"
@@ -27,4 +28,5 @@ type Chemo struct {
 	Doctor_Code        *string              `json:"doctor_code"`
 	Doctor             *ed.Doctor           `json:"doctor" gorm:"foreignKey:Doctor_Code;references:Code"`
 	NextChemoDate      *time.Time           `json:"nextChemoDate"`
+	Class_Code         ere.ChemoClassCode   `json:"class_code"`
 }
diff --git a/internal/use-case/main-use-case/chemo-protocol/helper.go b/internal/use-case/main-use-case/chemo-protocol/helper.go
index b3989d98..36ff70a6 100644
--- a/internal/use-case/main-use-case/chemo-protocol/helper.go
+++ b/internal/use-case/main-use-case/chemo-protocol/helper.go
@@ -5,15 +5,17 @@ Any functions that are used internally by the use-case
 package chemo_protocol
 
 import (
-	ec "simrs-vx/internal/domain/main-entities/chemo"
-	e "simrs-vx/internal/domain/main-entities/chemo-protocol"
-	erc "simrs-vx/internal/domain/references/common"
-	ere "simrs-vx/internal/domain/references/encounter"
 	pl "simrs-vx/pkg/logger"
 	pu "simrs-vx/pkg/use-case-helper"
 
 	dg "github.com/karincake/apem/db-gorm-pg"
 	gh "github.com/karincake/getuk"
+
+	erc "simrs-vx/internal/domain/references/common"
+	ere "simrs-vx/internal/domain/references/encounter"
+
+	ec "simrs-vx/internal/domain/main-entities/chemo"
+	e "simrs-vx/internal/domain/main-entities/chemo-protocol"
 )
 
 func setData[T *e.CreateDto | *e.UpdateDto](input T, data *e.ChemoProtocol) {