diff --git a/epdg/EPDG_Tests.ttcn b/epdg/EPDG_Tests.ttcn
index d8112e8..31963f4 100644
--- a/epdg/EPDG_Tests.ttcn
+++ b/epdg/EPDG_Tests.ttcn
@@ -19,6 +19,7 @@
 import from DIAMETER_Types all;
 import from DIAMETER_Templates all;
 import from DIAMETER_rfc4004_Templates all;
+import from DIAMETER_ts29_229_Templates all;
 import from DIAMETER_ts29_272_Templates all;
 import from DIAMETER_ts29_273_Templates all;
 import from DIAMETER_Emulation all;
@@ -470,6 +471,32 @@
 	}
 }
 
+/* Send RTR as HSS to AAA server, expect back RTA */
+private function f_DIA_SWx_RT(template (value) CxDx_3GPP_Reason_Code reason_code,
+			      template (present) GenericAVP exp_result_tmpl := tr_AVP_ResultCode(DIAMETER_SUCCESS)) runs on EPDG_ConnHdlr {
+	var PDU_DIAMETER rx_dia;
+	var UINT32 hbh_id := f_rnd_octstring(4);
+	var UINT32 ete_id := f_rnd_octstring(4);
+	var octetstring reason_info := char2oct("test");
+
+	/* Unlike STR, STA contains no IMSI. Register ete_id in DIAMETER_Emulation,
+	 * so AIA is forwarded back to us in DIAMETER port instead of MTC_CT.DIAMETER_UNIT.
+	 */
+	f_epdg_connhldr_SWx_expect_eteid(ete_id);
+
+	SWx.send(ts_DIA_SWx_RTR(g_pars.imsi, reason_code, reason_info,
+				hbh_id := hbh_id,
+				ete_id := ete_id));
+
+	alt {
+	[] SWx.receive(tr_DIA_SWx_RTA(exp_result_tmpl, hbh_id := hbh_id, ete_id := ete_id)) -> value rx_dia {}
+	[] SWx.receive(PDU_DIAMETER:?) -> value rx_dia {
+		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail, log2str("Unexpected Diameter SWx msg rx: ", rx_dia));
+		}
+	}
+}
+
+
 /* Send AAR as PGW to AAA server, expect back AAA */
 private function f_S6b_AA_success() runs on EPDG_ConnHdlr {
 	var PDU_DIAMETER rx_dia;
@@ -1025,6 +1052,24 @@
 	setverdict(pass);
 }
 
+/* 3GPP TS 29.273 Network Initiated De-Registration by HSS, Administrative */
+private function f_TC_hss_initiated_deregister_new_server_assigned(charstring id) runs on EPDG_ConnHdlr {
+	f_initial_attach();
+	/* Procedure should be performed properly: */
+	f_DIA_SWx_RT(NEW_SERVER_ASSIGNED, tr_AVP_ResultCode(DIAMETER_SUCCESS));
+	/* Subscriber was already removed, it should fail if requested again: */
+	var DIAMETER_ts29_229_ExperimentalResultcode erc := DIAMETER_ERROR_USER_UNKNOWN;
+	f_DIA_SWx_RT(NEW_SERVER_ASSIGNED, tr_AVP_ExperimentalResult(vendor_id_3GPP, int2oct(enum2int(erc), 4)));
+}
+testcase TC_hss_initiated_deregister_new_server_assigned() runs on MTC_CT {
+	var EPDG_ConnHdlrPars pars := f_init_pars();
+	var EPDG_ConnHdlr vc_conn;
+	f_init();
+	vc_conn := f_start_handler(refers(f_TC_hss_initiated_deregister_new_server_assigned), pars);
+	vc_conn.done;
+	setverdict(pass);
+}
+
 private function f_TC_concurrent_ues(charstring id) runs on EPDG_ConnHdlr {
 	COORD.send(COORD_CMD_READY);
 	COORD.receive(COORD_CMD_START);
@@ -1121,6 +1166,7 @@
 	execute ( TC_ho_lte_to_wifi() );
 	execute ( TC_ho_wifi_to_lte() );
 	execute ( TC_s2b_CreateSession_rejected() );
+	execute ( TC_hss_initiated_deregister_new_server_assigned() );
 	execute ( TC_concurrent_ues2() );
 	execute ( TC_concurrent_ues100() );
 	execute ( TC_upf_echo_req() );