diff --git a/idptoken/grpc_client.go b/idptoken/grpc_client.go
index d590418..8d61fe1 100644
--- a/idptoken/grpc_client.go
+++ b/idptoken/grpc_client.go
@@ -30,7 +30,10 @@ import (
 // DefaultGRPCClientRequestTimeout is a default timeout for the gRPC requests.
 const DefaultGRPCClientRequestTimeout = time.Second * 30
 
-const grpcMetaAuthorization = "authorization"
+const (
+	grpcMetaAuthorization = "authorization"
+	grpcMetaSessionID     = "x-caching-idp-session-id"
+)
 
 // GRPCClientOpts contains options for the GRPCClient.
 type GRPCClientOpts struct {
@@ -54,6 +57,8 @@ type GRPCClient struct {
 	clientConn  *grpc.ClientConn
 	reqTimeout  time.Duration
 	promMetrics *metrics.PrometheusMetrics
+
+	sessionID string
 }
 
 // NewGRPCClient creates a new GRPCClient instance that communicates with the IDP token service.
@@ -117,7 +122,11 @@ func (c *GRPCClient) IntrospectToken(
 		req.ScopeFilter[i] = &pb.IntrospectionScopeFilter{ResourceNamespace: scopeFilter[i].ResourceNamespace}
 	}
 
-	ctx = metadata.AppendToOutgoingContext(ctx, grpcMetaAuthorization, makeBearerToken(accessToken))
+	if c.sessionID != "" {
+		ctx = metadata.AppendToOutgoingContext(ctx, grpcMetaSessionID, c.sessionID)
+	} else {
+		ctx = metadata.AppendToOutgoingContext(ctx, grpcMetaAuthorization, makeBearerToken(accessToken))
+	}
 
 	var resp *pb.IntrospectTokenResponse
 	if err := c.do(ctx, "IDPTokenService/IntrospectToken", func(ctx context.Context) error {
@@ -128,6 +137,12 @@ func (c *GRPCClient) IntrospectToken(
 		return nil, err
 	}
 
+	if md, ok := metadata.FromIncomingContext(ctx); ok {
+		if sessionIDList := md.Get(grpcMetaSessionID); len(sessionIDList) > 0 {
+			c.sessionID = sessionIDList[0]
+		}
+	}
+
 	claims := jwt.DefaultClaims{
 		RegisteredClaims: jwtgo.RegisteredClaims{
 			Issuer:   resp.GetIss(),
diff --git a/idptoken/introspector.go b/idptoken/introspector.go
index 673beba..f9a9966 100644
--- a/idptoken/introspector.go
+++ b/idptoken/introspector.go
@@ -371,7 +371,10 @@ func (i *Introspector) introspectToken(ctx context.Context, token string) (Intro
 		return nil, err
 	}
 
-	// If introspection is unauthorized, then invalidate access token provider's cache and try again.
+	// If introspection is unauthorized, it is required to:
+	// 1. Drop current session id to issue an access token anew
+	i.GRPCClient.sessionID = ""
+	// 2. Invalidate access token provider's cache and try again.
 	// To avoid invalidating the cache too often, we have a threshold - minimum interval between invalidations.
 	t, ok := i.accessTokenProviderInvalidatedAt.Load().(time.Time)
 	now := time.Now()
@@ -520,9 +523,13 @@ func (i *Introspector) makeIntrospectFuncHTTP(introspectionEndpointURL string) i
 
 func (i *Introspector) makeIntrospectFuncGRPC() introspectFunc {
 	return func(ctx context.Context, token string) (IntrospectionResult, error) {
-		accessToken, err := i.accessTokenProvider.GetToken(ctx, i.accessTokenScope...)
-		if err != nil {
-			return nil, fmt.Errorf("get access token for doing introspection: %w", err)
+		var err error
+		var accessToken string
+		if i.GRPCClient.sessionID == "" {
+			accessToken, err = i.accessTokenProvider.GetToken(ctx, i.accessTokenScope...)
+			if err != nil {
+				return nil, fmt.Errorf("get access token for doing introspection: %w", err)
+			}
 		}
 		res, err := i.GRPCClient.IntrospectToken(ctx, token, i.scopeFilter, accessToken)
 		if err != nil {