diff --git a/channels/chan_pjsip.c b/channels/chan_pjsip.c
index a639d57630..5b03f88951 100644
--- a/channels/chan_pjsip.c
+++ b/channels/chan_pjsip.c
@@ -2577,16 +2577,23 @@ static int chan_pjsip_hangup(struct ast_channel *ast)
 {
 	struct ast_sip_channel_pvt *channel = ast_channel_tech_pvt(ast);
 	int cause;
+	int tech_cause;
+	int original_tech_cause;
 	struct hangup_data *h_data;
 	SCOPE_ENTER(1, "%s\n", ast_channel_name(ast));
 
 	if (!channel || !channel->session) {
-		SCOPE_EXIT_RTN_VALUE(-1, "No channel or session\n");
+		SCOPE_EXIT_RTN_VALUE(-1, "%s: No channel or session\n", ast_channel_name(ast));
 	}
 
-	cause = hangup_cause2sip(ast_channel_hangupcause(channel->session->channel));
-	h_data = hangup_data_alloc(cause, ast);
+	cause = ast_channel_hangupcause(channel->session->channel);
+	tech_cause = hangup_cause2sip(cause);
+	original_tech_cause = ast_channel_tech_hangupcause(channel->session->channel);
+	if (!original_tech_cause) {
+		ast_channel_tech_hangupcause_set(channel->session->channel, tech_cause);
+	}
 
+	h_data = hangup_data_alloc(tech_cause, ast);
 	if (!h_data) {
 		goto failure;
 	}
@@ -2596,7 +2603,8 @@ static int chan_pjsip_hangup(struct ast_channel *ast)
 		goto failure;
 	}
 
-	SCOPE_EXIT_RTN_VALUE(0, "Cause: %d\n", cause);
+	SCOPE_EXIT_RTN_VALUE(0, "%s: Cause: %d  Tech Cause: %d\n", ast_channel_name(ast),
+		cause, tech_cause);
 
 failure:
 	/* Go ahead and do our cleanup of the session and channel even if we're not going
@@ -2606,7 +2614,7 @@ failure:
 	ao2_cleanup(channel);
 	ao2_cleanup(h_data);
 
-	SCOPE_EXIT_RTN_VALUE(-1, "Cause: %d\n", cause);
+	SCOPE_EXIT_RTN_VALUE(-1, "%s: Cause: %d\n", ast_channel_name(ast), cause);
 }
 
 struct request_data {
@@ -2943,7 +2951,7 @@ static void chan_pjsip_session_end(struct ast_sip_session *session)
 	SCOPE_ENTER(1, "%s\n", ast_sip_session_get_name(session));
 
 	if (!session->channel) {
-		SCOPE_EXIT_RTN("No channel\n");
+		SCOPE_EXIT_RTN("%s: No channel\n", ast_sip_session_get_name(session));
 	}
 
 
@@ -2959,6 +2967,24 @@ static void chan_pjsip_session_end(struct ast_sip_session *session)
 	chan_pjsip_remove_hold(ast_channel_uniqueid(session->channel));
 
 	ast_set_hangupsource(session->channel, ast_channel_name(session->channel), 0);
+
+	ast_trace(-1, "%s: channel cause: %d\n", ast_sip_session_get_name(session),
+		ast_channel_hangupcause(session->channel));
+
+	if (session->inv_session) {
+		/*
+		 * tech_hangupcause should only be set if off-nominal.
+		 */
+		if (session->inv_session->cause / 100 > 2) {
+			ast_trace(-1, "%s: inv_session cause: %d\n", ast_sip_session_get_name(session),
+				session->inv_session->cause);
+			ast_channel_tech_hangupcause_set(session->channel, session->inv_session->cause);
+		} else {
+			ast_trace(-1, "%s: inv_session cause: %d suppressed\n", ast_sip_session_get_name(session),
+				session->inv_session->cause);
+		}
+	}
+
 	if (!ast_channel_hangupcause(session->channel) && session->inv_session) {
 		int cause = ast_sip_hangup_sip2cause(session->inv_session->cause);
 
@@ -2967,7 +2993,7 @@ static void chan_pjsip_session_end(struct ast_sip_session *session)
 		ast_queue_hangup(session->channel);
 	}
 
-	SCOPE_EXIT_RTN();
+	SCOPE_EXIT_RTN("%s\n", ast_sip_session_get_name(session));
 }
 
 static void set_sipdomain_variable(struct ast_sip_session *session)
diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index eceb9aa9f2..276037b25d 100644
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -4197,6 +4197,8 @@ int ast_channel_fdno(const struct ast_channel *chan);
 void ast_channel_fdno_set(struct ast_channel *chan, int value);
 int ast_channel_hangupcause(const struct ast_channel *chan);
 void ast_channel_hangupcause_set(struct ast_channel *chan, int value);
+int ast_channel_tech_hangupcause(const struct ast_channel *chan);
+void ast_channel_tech_hangupcause_set(struct ast_channel *chan, int value);
 int ast_channel_priority(const struct ast_channel *chan);
 void ast_channel_priority_set(struct ast_channel *chan, int value);
 int ast_channel_rings(const struct ast_channel *chan);
diff --git a/include/asterisk/stasis_channels.h b/include/asterisk/stasis_channels.h
index 86422540ae..863973683e 100644
--- a/include/asterisk/stasis_channels.h
+++ b/include/asterisk/stasis_channels.h
@@ -132,7 +132,9 @@ struct ast_channel_snapshot_peer {
  */
 struct ast_channel_snapshot_hangup {
 	int cause;      /*!< Why is the channel hanged up. See causes.h */
-	char source[0]; /*!< Who is responsible for hanging up this channel */
+	char *source;   /*!< Who is responsible for hanging up this channel */
+	int tech_cause; /*!< Technology-specific hangup cause */
+	char buffer[0]; /*!< \private Buffer to store source in */
 };
 
 /*!
diff --git a/main/channel.c b/main/channel.c
index 2de4bf85d5..987ea40a3d 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -1180,9 +1180,13 @@ int ast_queue_frame_head(struct ast_channel *chan, struct ast_frame *fin)
 /*! \brief Queue a hangup frame for channel */
 int ast_queue_hangup(struct ast_channel *chan)
 {
-	RAII_VAR(struct ast_json *, blob, NULL, ast_json_unref);
+	RAII_VAR(struct ast_json *, blob, ast_json_object_create(), ast_json_unref);
 	struct ast_frame f = { AST_FRAME_CONTROL, .subclass.integer = AST_CONTROL_HANGUP };
-	int res, cause;
+	int res, cause, tech_cause;
+
+	if (!blob) {
+		return -1;
+	}
 
 	/* Yeah, let's not change a lock-critical value without locking */
 	ast_channel_lock(chan);
@@ -1190,8 +1194,11 @@ int ast_queue_hangup(struct ast_channel *chan)
 
 	cause = ast_channel_hangupcause(chan);
 	if (cause) {
-		blob = ast_json_pack("{s: i}",
-			"cause", cause);
+		ast_json_object_set(blob, "cause", ast_json_integer_create(cause));
+	}
+	tech_cause = ast_channel_tech_hangupcause(chan);
+	if (tech_cause) {
+		ast_json_object_set(blob, "tech_cause", ast_json_integer_create(tech_cause));
 	}
 
 	ast_channel_publish_blob(chan, ast_channel_hangup_request_type(), blob);
@@ -1207,6 +1214,7 @@ int ast_queue_hangup_with_cause(struct ast_channel *chan, int cause)
 	RAII_VAR(struct ast_json *, blob, NULL, ast_json_unref);
 	struct ast_frame f = { AST_FRAME_CONTROL, .subclass.integer = AST_CONTROL_HANGUP };
 	int res;
+	int tech_cause = 0;
 
 	if (cause >= 0) {
 		f.data.uint32 = cause;
@@ -1220,6 +1228,16 @@ int ast_queue_hangup_with_cause(struct ast_channel *chan, int cause)
 	}
 	blob = ast_json_pack("{s: i}",
 			     "cause", cause);
+	if (!blob) {
+		ast_channel_unlock(chan);
+		return -1;
+	}
+
+	tech_cause = ast_channel_tech_hangupcause(chan);
+	if (tech_cause) {
+		ast_json_object_set(blob, "tech_cause", ast_json_integer_create(tech_cause));
+	}
+
 	ast_channel_publish_blob(chan, ast_channel_hangup_request_type(), blob);
 
 	res = ast_queue_frame(chan, &f);
@@ -2444,12 +2462,19 @@ int ast_softhangup(struct ast_channel *chan, int cause)
 {
 	RAII_VAR(struct ast_json *, blob, NULL, ast_json_unref);
 	int res;
+	int tech_cause = 0;
 
 	ast_channel_lock(chan);
 	res = ast_softhangup_nolock(chan, cause);
 	blob = ast_json_pack("{s: i, s: b}",
 			     "cause", cause,
 			     "soft", 1);
+
+	tech_cause = ast_channel_tech_hangupcause(chan);
+	if (tech_cause) {
+		ast_json_object_set(blob, "tech_cause", ast_json_integer_create(tech_cause));
+	}
+
 	ast_channel_publish_blob(chan, ast_channel_hangup_request_type(), blob);
 	ast_channel_unlock(chan);
 
diff --git a/main/channel_internal_api.c b/main/channel_internal_api.c
index ce2f7d5d64..9b41811bd9 100644
--- a/main/channel_internal_api.c
+++ b/main/channel_internal_api.c
@@ -304,6 +304,15 @@ void ast_channel_hangupcause_set(struct ast_channel *chan, int value)
 	chan->hangupcause = value;
 	ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_HANGUP);
 }
+int ast_channel_tech_hangupcause(const struct ast_channel *chan)
+{
+	return chan->tech_hangupcause;
+}
+void ast_channel_tech_hangupcause_set(struct ast_channel *chan, int value)
+{
+	chan->tech_hangupcause = value;
+	ast_channel_snapshot_invalidate_segment(chan, AST_CHANNEL_SNAPSHOT_INVALIDATE_HANGUP);
+}
 int ast_channel_priority(const struct ast_channel *chan)
 {
 	return chan->priority;
diff --git a/main/channel_private.h b/main/channel_private.h
index 5842f43da7..3ff56128fa 100644
--- a/main/channel_private.h
+++ b/main/channel_private.h
@@ -158,7 +158,10 @@ struct ast_channel {
 							 *   the counter is only in the remaining bits */
 	unsigned int fout;				/*!< Frames out counters. The high bit is a debug mask, so
 							 *   the counter is only in the remaining bits */
-	int hangupcause;				/*!< Why is the channel hanged up. See causes.h */
+	int hangupcause;                /*!< Why is the channel hanged up. See causes.h */
+	int tech_hangupcause;           /*!< Technology-specific off-nominal hangup cause.
+                                     * Leave set to 0 for nominal call termination.
+                                     */
 	unsigned int finalized:1;       /*!< Whether or not the channel has been successfully allocated */
 	struct ast_flags flags;				/*!< channel flags of AST_FLAG_ type */
 	int alertpipe[2];
diff --git a/main/manager_channels.c b/main/manager_channels.c
index 35d82f099e..6e56d0fe63 100644
--- a/main/manager_channels.c
+++ b/main/manager_channels.c
@@ -80,6 +80,11 @@
 				<parameter name="Cause-txt">
 					<para>A description of why the channel was hung up.</para>
 				</parameter>
+				<parameter name="TechCause">
+					<para>A technology-specific off-nominal numeric cause code
+					for why the channel was hung up.  Suppressed for nominally
+					terminated calls.</para>
+				</parameter>
 			</syntax>
 			<see-also>
 				<ref type="managerEvent">Newchannel</ref>
@@ -641,12 +646,23 @@ static struct ast_manager_event_blob *channel_state_change(
 	is_hungup = ast_test_flag(&new_snapshot->flags, AST_FLAG_DEAD) ? 1 : 0;
 
 	if (!was_hungup && is_hungup) {
-		return ast_manager_event_blob_create(
-			EVENT_FLAG_CALL, "Hangup",
-			"Cause: %d\r\n"
-			"Cause-txt: %s\r\n",
-			new_snapshot->hangup->cause,
-			ast_cause2str(new_snapshot->hangup->cause));
+		if (new_snapshot->hangup->tech_cause) {
+			return ast_manager_event_blob_create(
+				EVENT_FLAG_CALL, "Hangup",
+				"Cause: %d\r\n"
+				"Cause-txt: %s\r\n"
+				"TechCause: %d\r\n",
+				new_snapshot->hangup->cause,
+				ast_cause2str(new_snapshot->hangup->cause),
+				new_snapshot->hangup->tech_cause);
+		} else {
+			return ast_manager_event_blob_create(
+				EVENT_FLAG_CALL, "Hangup",
+				"Cause: %d\r\n"
+				"Cause-txt: %s\r\n",
+				new_snapshot->hangup->cause,
+				ast_cause2str(new_snapshot->hangup->cause));
+		}
 	}
 
 	if (old_snapshot->state != new_snapshot->state) {
@@ -815,6 +831,7 @@ static void channel_hangup_request_cb(void *data,
 	struct ast_str *extra;
 	struct ast_str *channel_event_string;
 	struct ast_json *cause;
+	struct ast_json *tech_cause;
 	int is_soft;
 	char *manager_event = "HangupRequest";
 
@@ -841,6 +858,13 @@ static void channel_hangup_request_cb(void *data,
 			ast_json_integer_get(cause));
 	}
 
+	tech_cause = ast_json_object_get(obj->blob, "tech_cause");
+	if (tech_cause) {
+		ast_str_append(&extra, 0,
+			"TechCause: %jd\r\n",
+			ast_json_integer_get(tech_cause));
+	}
+
 	is_soft = ast_json_is_true(ast_json_object_get(obj->blob, "soft"));
 	if (is_soft) {
 		manager_event = "SoftHangupRequest";
diff --git a/main/stasis_channels.c b/main/stasis_channels.c
index 4e74733935..3913a246f6 100644
--- a/main/stasis_channels.c
+++ b/main/stasis_channels.c
@@ -469,6 +469,8 @@ static struct ast_channel_snapshot_hangup *channel_snapshot_hangup_create(struct
 	}
 
 	snapshot->cause = ast_channel_hangupcause(chan);
+	snapshot->tech_cause = ast_channel_tech_hangupcause(chan);
+	snapshot->source = snapshot->buffer;
 	strcpy(snapshot->source, hangupsource); /* Safe */
 
 	return snapshot;
diff --git a/res/ari/ari_model_validators.c b/res/ari/ari_model_validators.c
index 5ef3821112..ae38f60ccf 100644
--- a/res/ari/ari_model_validators.c
+++ b/res/ari/ari_model_validators.c
@@ -4094,6 +4094,15 @@ int ast_ari_validate_channel_destroyed(struct ast_json *json)
 				res = 0;
 			}
 		} else
+		if (strcmp("tech_cause", ast_json_object_iter_key(iter)) == 0) {
+			int prop_is_valid;
+			prop_is_valid = ast_ari_validate_int(
+				ast_json_object_iter_value(iter));
+			if (!prop_is_valid) {
+				ast_log(LOG_ERROR, "ARI ChannelDestroyed field tech_cause failed validation\n");
+				res = 0;
+			}
+		} else
 		{
 			ast_log(LOG_ERROR,
 				"ARI ChannelDestroyed has undocumented field %s\n",
@@ -4575,6 +4584,15 @@ int ast_ari_validate_channel_hangup_request(struct ast_json *json)
 				res = 0;
 			}
 		} else
+		if (strcmp("tech_cause", ast_json_object_iter_key(iter)) == 0) {
+			int prop_is_valid;
+			prop_is_valid = ast_ari_validate_int(
+				ast_json_object_iter_value(iter));
+			if (!prop_is_valid) {
+				ast_log(LOG_ERROR, "ARI ChannelHangupRequest field tech_cause failed validation\n");
+				res = 0;
+			}
+		} else
 		{
 			ast_log(LOG_ERROR,
 				"ARI ChannelHangupRequest has undocumented field %s\n",
diff --git a/res/ari/ari_model_validators.h b/res/ari/ari_model_validators.h
index 58701c2af1..0b0762b523 100644
--- a/res/ari/ari_model_validators.h
+++ b/res/ari/ari_model_validators.h
@@ -1747,6 +1747,7 @@ ari_validator ast_ari_validate_application_fn(void);
  * - cause: int (required)
  * - cause_txt: string (required)
  * - channel: Channel (required)
+ * - tech_cause: int
  * ChannelDialplan
  * - asterisk_id: string
  * - type: string (required)
@@ -1778,6 +1779,7 @@ ari_validator ast_ari_validate_application_fn(void);
  * - cause: int
  * - channel: Channel (required)
  * - soft: boolean
+ * - tech_cause: int
  * ChannelHold
  * - asterisk_id: string
  * - type: string (required)
diff --git a/res/stasis/app.c b/res/stasis/app.c
index 3709033897..57131844ed 100644
--- a/res/stasis/app.c
+++ b/res/stasis/app.c
@@ -402,17 +402,30 @@ static struct ast_json *channel_destroyed_event(
 	const struct timeval *tv)
 {
 	struct ast_json *json_channel = ast_channel_snapshot_to_json(snapshot, stasis_app_get_sanitizer());
+	struct ast_json *blob;
 
 	if (!json_channel) {
 		return NULL;
 	}
 
-	return ast_json_pack("{s: s, s: o, s: i, s: s, s: o}",
+	blob = ast_json_pack("{s: s, s: o, s: i, s: s}",
 		"type", "ChannelDestroyed",
 		"timestamp", ast_json_timeval(*tv, NULL),
 		"cause", snapshot->hangup->cause,
-		"cause_txt", ast_cause2str(snapshot->hangup->cause),
-		"channel", json_channel);
+		"cause_txt", ast_cause2str(snapshot->hangup->cause));
+
+	if (!blob) {
+		return NULL;
+	}
+
+	if (snapshot->hangup->tech_cause) {
+		ast_json_object_set(blob, "tech_cause",
+			ast_json_integer_create(snapshot->hangup->tech_cause));
+	}
+
+	ast_json_object_set(blob, "channel", json_channel);
+
+	return blob;
 }
 
 static struct ast_json *channel_state_change_event(
diff --git a/rest-api/api-docs/events.json b/rest-api/api-docs/events.json
index fd300981b6..f08a665ef2 100644
--- a/rest-api/api-docs/events.json
+++ b/rest-api/api-docs/events.json
@@ -579,6 +579,10 @@
 					"description": "Text representation of the cause of the hangup",
 					"type": "string"
 				},
+				"tech_cause": {
+					"type": "int",
+					"description": "Integer representation of the technology-specific off-nominal cause of the hangup."
+				},
 				"channel": {
 					"required": true,
 					"type": "Channel"
@@ -724,6 +728,10 @@
 					"type": "int",
 					"description": "Integer representation of the cause of the hangup."
 				},
+				"tech_cause": {
+					"type": "int",
+					"description": "Integer representation of the technology-specific off-nominal cause of the hangup."
+				},
 				"soft": {
 					"type": "boolean",
 					"description": "Whether the hangup request was a soft hangup request."