diff --git a/netmap/types.go b/netmap/types.go
index af8fb6ff..dc328053 100644
--- a/netmap/types.go
+++ b/netmap/types.go
@@ -59,6 +59,7 @@ type PlacementPolicy struct {
 	backupFactor uint32
 	selectors    []*Selector
 	filters      []*Filter
+	subnetID     *refs.SubnetID
 }
 
 // Attribute of storage node.
@@ -330,6 +331,14 @@ func (p *PlacementPolicy) SetReplicas(replicas []*Replica) {
 	p.replicas = replicas
 }
 
+func (p *PlacementPolicy) GetSubnetID() *refs.SubnetID {
+	return p.subnetID
+}
+
+func (p *PlacementPolicy) SetSubnetID(id *refs.SubnetID) {
+	p.subnetID = id
+}
+
 func (a *Attribute) GetKey() string {
 	if a != nil {
 		return a.key
diff --git a/refs/types.go b/refs/types.go
index 0b902684..f3ce1455 100644
--- a/refs/types.go
+++ b/refs/types.go
@@ -30,6 +30,10 @@ type Signature struct {
 	key, sign []byte
 }
 
+type SubnetID struct {
+	value uint32
+}
+
 type Version struct {
 	major, minor uint32
 }
@@ -166,6 +170,19 @@ func (s *Signature) SetSign(v []byte) {
 	}
 }
 
+func (s *SubnetID) SetValue(id uint32) {
+	if s != nil {
+		s.value = id
+	}
+}
+
+func (s *SubnetID) GetValue() uint32 {
+	if s != nil {
+		return s.value
+	}
+	return 0
+}
+
 func (v *Version) GetMajor() uint32 {
 	if v != nil {
 		return v.major