diff --git a/coserv/quads.go b/coserv/quads.go
index 69a29cad..f5f8d25f 100644
--- a/coserv/quads.go
+++ b/coserv/quads.go
@@ -3,7 +3,10 @@
 
 package coserv
 
-import "github.com/veraison/corim/comid"
+import (
+	"github.com/veraison/corim/comid"
+	"github.com/veraison/corim/cots"
+)
 
 type RefValQuad struct {
 	Authorities *comid.CryptoKeys  `cbor:"1,keyasint"`
@@ -14,3 +17,8 @@ type AKQuad struct {
 	Authorities *comid.CryptoKeys `cbor:"1,keyasint"`
 	AKTriple    *comid.KeyTriple  `cbor:"2,keyasint"`
 }
+
+type CoTSStmt struct {
+	Authorities *comid.CryptoKeys    `cbor:"1,keyasint"`
+	CoTS        *cots.ConciseTaStore `cbor:"2,keyasint"`
+}
diff --git a/coserv/resultset.go b/coserv/resultset.go
index 87d9b711..1dd5ccf4 100644
--- a/coserv/resultset.go
+++ b/coserv/resultset.go
@@ -13,8 +13,8 @@ import (
 type ResultSet struct {
 	RVQ *[]RefValQuad `cbor:"0,keyasint,omitempty"`
 	AKQ *[]AKQuad     `cbor:"3,keyasint,omitempty"`
+	TAS *[]CoTSStmt   `cbor:"4,keyasint,omitempty"`
 	// TODO(tho) add endorsed values
-	// TODO(tho) add CoTS
 	Expiry          *time.Time `cbor:"10,keyasint"`
 	SourceArtifacts *[]cmw.CMW `cbor:"11,keyasint,omitempty"`
 }
@@ -46,6 +46,17 @@ func (o *ResultSet) AddAttestationKeys(v AKQuad) *ResultSet {
 	return o
 }
 
+// AddCoTS adds the supplied CoTS statement to the target ResultSet
+func (o *ResultSet) AddCoTS(v CoTSStmt) *ResultSet {
+	if o.TAS == nil {
+		o.TAS = new([]CoTSStmt)
+	}
+
+	*o.TAS = append(*o.TAS, v)
+
+	return o
+}
+
 // AddSourceArtifacts adds the supplied CMW to the target ResultSet
 func (o *ResultSet) AddSourceArtifacts(v cmw.CMW) *ResultSet { // nolint:gocritic
 	if o.SourceArtifacts == nil {
diff --git a/coserv/resultset_test.go b/coserv/resultset_test.go
index 96e831e3..eb1a951c 100644
--- a/coserv/resultset_test.go
+++ b/coserv/resultset_test.go
@@ -10,6 +10,7 @@ import (
 	"github.com/stretchr/testify/require"
 	"github.com/veraison/cmw"
 	"github.com/veraison/corim/comid"
+	"github.com/veraison/corim/cots"
 )
 
 func TestResultSet_AddAttestationKeys(t *testing.T) {
@@ -32,6 +33,39 @@ func TestResultSet_AddAttestationKeys(t *testing.T) {
 	assert.NotNil(t, rset)
 }
 
+func TestResultSet_AddCoTS(t *testing.T) {
+	authority, err := comid.NewCryptoKeyTaggedBytes(testAuthority)
+	require.NoError(t, err)
+
+	// Create a simple CoTS structure for testing
+	cotsStore := cots.NewConciseTaStore()
+
+	// Add a basic environment group with a class
+	class := comid.NewClassBytes(testBytes)
+	env := comid.Environment{
+		Class: class,
+	}
+	eg := cots.EnvironmentGroup{}
+	eg.SetEnvironment(env)
+	cotsStore.AddEnvironmentGroup(eg)
+
+	// Add trust anchor keys
+	testCert := []byte{0x30, 0x82, 0x01, 0x00} // Simple test cert bytes
+	tas := cots.NewTasAndCas()
+	tas.AddTaCert(testCert)
+	cotsStore.SetKeys(*tas)
+
+	cotsStmt := CoTSStmt{
+		Authorities: comid.NewCryptoKeys().Add(authority),
+		CoTS:        cotsStore,
+	}
+
+	rset := NewResultSet().SetExpiry(testExpiry).AddCoTS(cotsStmt)
+	assert.NotNil(t, rset)
+	assert.NotNil(t, rset.TAS)
+	assert.Equal(t, 1, len(*rset.TAS))
+}
+
 func TestResultSet_AddSourceArtifacts(t *testing.T) {
 	cmw0, err := cmw.NewMonad("application/vnd.example.refvals", []byte{0x00, 0x01, 0x02, 0x03})
 	require.NoError(t, err)