diff --git a/apps/app_voicemail.c b/apps/app_voicemail.c
index c0edd447b5ce4e443ae1cabb76d869650b09c29a..5603bb5b5ff624f450078231058414a748c2cf6f 100644
--- a/apps/app_voicemail.c
+++ b/apps/app_voicemail.c
@@ -1016,43 +1016,8 @@ static ast_cond_t poll_cond = PTHREAD_COND_INITIALIZER;
 static pthread_t poll_thread = AST_PTHREADT_NULL;
 static unsigned char poll_thread_run;
 
-/*! Subscription to MWI event subscription changes */
-static struct stasis_subscription *mwi_sub_sub;
-
-/*!
- * \brief An MWI subscription
- *
- * This is so we can keep track of which mailboxes are subscribed to.
- * This way, we know which mailboxes to poll when the pollmailboxes
- * option is being used.
- */
-struct mwi_sub {
-	AST_RWLIST_ENTRY(mwi_sub) entry;
-	int old_urgent;
-	int old_new;
-	int old_old;
-	char *uniqueid;
-	char mailbox[0];
-};
-
-struct mwi_sub_task {
-	const char *mailbox;
-	const char *context;
-	const char *uniqueid;
-};
-
-static void mwi_sub_task_dtor(struct mwi_sub_task *mwist)
-{
-	ast_free((void *) mwist->mailbox);
-	ast_free((void *) mwist->context);
-	ast_free((void *) mwist->uniqueid);
-	ast_free(mwist);
-}
-
 static struct ast_taskprocessor *mwi_subscription_tps;
 
-static AST_RWLIST_HEAD_STATIC(mwi_subs, mwi_sub);
-
 struct alias_mailbox_mapping {
 	char *alias;
 	char *mailbox;
@@ -6316,7 +6281,7 @@ static int inboxcount(const char *mailbox, int *newmsgs, int *oldmsgs)
 	return res;
 }
 
-static void run_externnotify(char *context, char *extension, const char *flag)
+static void run_externnotify(const char *context, const char *extension, const char *flag)
 {
 	char arguments[255];
 	char ext_context[256] = "";
@@ -13197,38 +13162,29 @@ static struct ast_cli_entry cli_voicemail[] = {
 	AST_CLI_DEFINE(handle_voicemail_reload, "Reload voicemail configuration"),
 };
 
-static void poll_subscribed_mailbox(struct mwi_sub *mwi_sub)
+static int poll_subscribed_mailbox(struct ast_mwi_state *mwi_state, void *data)
 {
 	int new = 0, old = 0, urgent = 0;
 
-	inboxcount2(mwi_sub->mailbox, &urgent, &new, &old);
+	if (!mwi_state) {
+		/* This should only occur due to allocation failure of a default mwi state object */
+		return 0;
+	}
+
+	inboxcount2(mwi_state->uniqueid, &urgent, &new, &old);
 
 #ifdef IMAP_STORAGE
 	if (imap_poll_logout) {
-		imap_logout(mwi_sub->mailbox);
+		imap_logout(mwi_state->uniqueid);
 	}
 #endif
 
-	if (urgent != mwi_sub->old_urgent || new != mwi_sub->old_new || old != mwi_sub->old_old) {
-		mwi_sub->old_urgent = urgent;
-		mwi_sub->old_new = new;
-		mwi_sub->old_old = old;
-		queue_mwi_event(NULL, mwi_sub->mailbox, urgent, new, old);
-		run_externnotify(NULL, mwi_sub->mailbox, NULL);
+	if (urgent != mwi_state->urgent_msgs || new != mwi_state->new_msgs || old != mwi_state->old_msgs) {
+		queue_mwi_event(NULL, mwi_state->uniqueid, urgent, new, old);
+		run_externnotify(NULL, mwi_state->uniqueid, NULL);
 	}
-}
 
-static void poll_subscribed_mailboxes(void)
-{
-	struct mwi_sub *mwi_sub;
-
-	AST_RWLIST_RDLOCK(&mwi_subs);
-	AST_RWLIST_TRAVERSE(&mwi_subs, mwi_sub, entry) {
-		if (!ast_strlen_zero(mwi_sub->mailbox)) {
-			poll_subscribed_mailbox(mwi_sub);
-		}
-	}
-	AST_RWLIST_UNLOCK(&mwi_subs);
+	return 0;
 }
 
 static void *mb_poll_thread(void *data)
@@ -13237,6 +13193,12 @@ static void *mb_poll_thread(void *data)
 		struct timespec ts = { 0, };
 		struct timeval wait;
 
+		ast_mwi_state_callback_subscribed(poll_subscribed_mailbox, NULL);
+
+		if (!poll_thread_run) {
+			break;
+		}
+
 		wait = ast_tvadd(ast_tvnow(), ast_samp2tv(poll_freq, 1));
 		ts.tv_sec = wait.tv_sec;
 		ts.tv_nsec = wait.tv_usec * 1000;
@@ -13244,22 +13206,11 @@ static void *mb_poll_thread(void *data)
 		ast_mutex_lock(&poll_lock);
 		ast_cond_timedwait(&poll_cond, &poll_lock, &ts);
 		ast_mutex_unlock(&poll_lock);
-
-		if (!poll_thread_run)
-			break;
-
-		poll_subscribed_mailboxes();
 	}
 
 	return NULL;
 }
 
-static void mwi_sub_destroy(struct mwi_sub *mwi_sub)
-{
-	ast_free(mwi_sub->uniqueid);
-	ast_free(mwi_sub);
-}
-
 #ifdef IMAP_STORAGE
 static void imap_logout(const char *mailbox_id)
 {
@@ -13295,157 +13246,74 @@ static void imap_logout(const char *mailbox_id)
 	vmstate_delete(vms);
 }
 
-static void imap_close_subscribed_mailboxes(void)
-{
-	struct mwi_sub *mwi_sub;
-
-	AST_RWLIST_RDLOCK(&mwi_subs);
-	AST_RWLIST_TRAVERSE(&mwi_subs, mwi_sub, entry) {
-		if (!ast_strlen_zero(mwi_sub->mailbox)) {
-			imap_logout(mwi_sub->mailbox);
-		}
-	}
-	AST_RWLIST_UNLOCK(&mwi_subs);
-}
-#endif
-
-static int handle_unsubscribe(void *datap)
+static int imap_close_subscribed_mailbox(struct ast_mwi_state *mwi_state, void *data)
 {
-	struct mwi_sub *mwi_sub;
-	char *uniqueid = datap;
-
-	AST_RWLIST_WRLOCK(&mwi_subs);
-	AST_RWLIST_TRAVERSE_SAFE_BEGIN(&mwi_subs, mwi_sub, entry) {
-		if (!strcmp(mwi_sub->uniqueid, uniqueid)) {
-			AST_LIST_REMOVE_CURRENT(entry);
-			/* Don't break here since a duplicate uniqueid
-			 * may have been added as a result of a cache dump. */
-#ifdef IMAP_STORAGE
-			imap_logout(mwi_sub->mailbox);
-#endif
-			mwi_sub_destroy(mwi_sub);
-		}
+	if (mwi_state && !ast_strlen_zero(mwi_state->uniqueid)) {
+		imap_logout(mwi_state->uniqueid);
 	}
-	AST_RWLIST_TRAVERSE_SAFE_END
-	AST_RWLIST_UNLOCK(&mwi_subs);
 
-	ast_free(uniqueid);
 	return 0;
 }
 
-static int handle_subscribe(void *datap)
-{
-	unsigned int len;
-	struct mwi_sub *mwi_sub;
-	struct mwi_sub_task *p = datap;
-
-	len = sizeof(*mwi_sub) + 1;
-	if (!ast_strlen_zero(p->mailbox))
-		len += strlen(p->mailbox);
-
-	if (!ast_strlen_zero(p->context))
-		len += strlen(p->context) + 1; /* Allow for seperator */
+#endif
 
-	if (!(mwi_sub = ast_calloc(1, len)))
-		return -1;
+static int mwi_handle_unsubscribe2(void *data)
+{
+	struct ast_mwi_state *mwi_state = data;
 
-	mwi_sub->uniqueid = ast_strdup(p->uniqueid);
-	if (!ast_strlen_zero(p->mailbox))
-		strcpy(mwi_sub->mailbox, p->mailbox);
+	/*
+	 * Go ahead and clear the implicit MWI publisher here to avoid a leak. If a backing
+	 * configuration is available it'll re-initialize (reset the cached state) on its
+	 * next publish.
+	 */
+	ast_delete_mwi_state_full(mwi_state->uniqueid, NULL, NULL);
 
-	if (!ast_strlen_zero(p->context)) {
-		strcat(mwi_sub->mailbox, "@");
-		strcat(mwi_sub->mailbox, p->context);
-	}
+#ifdef IMAP_STORAGE
+	imap_close_subscribed_mailbox(mwi_state, NULL);
+#endif
 
-	AST_RWLIST_WRLOCK(&mwi_subs);
-	AST_RWLIST_INSERT_TAIL(&mwi_subs, mwi_sub, entry);
-	AST_RWLIST_UNLOCK(&mwi_subs);
-	mwi_sub_task_dtor(p);
-	poll_subscribed_mailbox(mwi_sub);
+	ao2_ref(mwi_state, -1);
 	return 0;
 }
 
-static void mwi_unsub_event_cb(struct stasis_subscription_change *change)
+static void mwi_handle_unsubscribe(const char *id, struct ast_mwi_subscriber *sub)
 {
-	char *uniqueid = ast_strdup(change->uniqueid);
-
-	if (!uniqueid) {
-		ast_log(LOG_ERROR, "Unable to allocate memory for uniqueid\n");
-		return;
-	}
+	void *data = ast_mwi_subscriber_data(sub);
 
-	if (ast_taskprocessor_push(mwi_subscription_tps, handle_unsubscribe, uniqueid) < 0) {
-		ast_free(uniqueid);
+	/* Don't bump data's reference. We'll just use the one returned above */
+	if (ast_taskprocessor_push(mwi_subscription_tps, mwi_handle_unsubscribe2, data) < 0) {
+		/* A reference was returned for data when retrieving, so remove it on error */
+		ao2_ref(data, -1);
 	}
 }
 
-static void mwi_sub_event_cb(struct stasis_subscription_change *change)
+static int mwi_handle_subscribe2(void *data)
 {
-	struct mwi_sub_task *mwist;
-	const char *topic;
-	char *context;
-	char *mailbox;
-
-	mwist = ast_calloc(1, (sizeof(*mwist)));
-	if (!mwist) {
-		return;
-	}
-
-	/* The topic name is prefixed with "mwi:all/" as this is a pool topic */
-	topic = stasis_topic_name(change->topic) + 8;
-	if (separate_mailbox(ast_strdupa(topic), &mailbox, &context)) {
-		ast_free(mwist);
-		return;
-	}
-
-	mwist->mailbox = ast_strdup(mailbox);
-	mwist->context = ast_strdup(context);
-	mwist->uniqueid = ast_strdup(change->uniqueid);
-
-	if (ast_taskprocessor_push(mwi_subscription_tps, handle_subscribe, mwist) < 0) {
-		mwi_sub_task_dtor(mwist);
-	}
+	poll_subscribed_mailbox(data, NULL);
+	ao2_ref(data, -1);
+	return 0;
 }
 
-static void mwi_event_cb(void *userdata, struct stasis_subscription *sub, struct stasis_message *msg)
+static void mwi_handle_subscribe(const char *id, struct ast_mwi_subscriber *sub)
 {
-	struct stasis_subscription_change *change;
-	/* Only looking for subscription change notices here */
-	if (stasis_message_type(msg) != stasis_subscription_change_type()) {
-		return;
-	}
-	change = stasis_message_data(msg);
-	if (change->topic == ast_mwi_topic_all()) {
-		return;
-	}
+	void *data = ast_mwi_subscriber_data(sub);
 
-	if (!strcmp(change->description, "Subscribe")) {
-		mwi_sub_event_cb(change);
-	} else if (!strcmp(change->description, "Unsubscribe")) {
-		mwi_unsub_event_cb(change);
+	/* Don't bump data's reference. We'll just use the one returned above */
+	if (ast_taskprocessor_push(mwi_subscription_tps, mwi_handle_subscribe2, data) < 0) {
+		/* A reference was returned for data when retrieving, so remove it on error */
+		ao2_ref(data, -1);
 	}
 }
 
-static int dump_cache(void *obj, void *arg, int flags)
-{
-	struct stasis_message *msg = obj;
-	mwi_event_cb(NULL, NULL, msg);
-	return 0;
-}
+struct ast_mwi_observer mwi_observer = {
+	.on_subscribe = mwi_handle_subscribe,
+	.on_unsubscribe = mwi_handle_unsubscribe,
+};
 
 static void start_poll_thread(void)
 {
 	int errcode;
-	mwi_sub_sub = stasis_subscribe(ast_mwi_topic_all(), mwi_event_cb, NULL);
-
-	if (mwi_sub_sub) {
-		struct ao2_container *cached = stasis_cache_dump(ast_mwi_state_cache(), stasis_subscription_change_type());
-		if (cached) {
-			ao2_callback(cached, OBJ_MULTIPLE | OBJ_NODATA, dump_cache, NULL);
-		}
-		ao2_cleanup(cached);
-	}
+	ast_mwi_add_observer(&mwi_observer);
 
 	poll_thread_run = 1;
 
@@ -13458,15 +13326,14 @@ static void stop_poll_thread(void)
 {
 	poll_thread_run = 0;
 
-	mwi_sub_sub = stasis_unsubscribe_and_join(mwi_sub_sub);
-
 	ast_mutex_lock(&poll_lock);
 	ast_cond_signal(&poll_cond);
 	ast_mutex_unlock(&poll_lock);
 
 	pthread_join(poll_thread, NULL);
-
 	poll_thread = AST_PTHREADT_NULL;
+
+	ast_mwi_remove_observer(&mwi_observer);
 }
 
 /*!
@@ -13590,38 +13457,40 @@ static int append_vmu_info_astman(
 
 }
 
-static int manager_voicemail_refresh(struct mansession *s, const struct message *m)
+static int manager_match_mailbox(struct ast_mwi_state *mwi_state, void *data)
 {
-	const char *context = astman_get_header(m, "Context");
-	const char *mailbox = astman_get_header(m, "Mailbox");
-	struct mwi_sub *mwi_sub;
+	const char *context = astman_get_header(data, "Context");
+	const char *mailbox = astman_get_header(data, "Mailbox");
 	const char *at;
 
-	AST_RWLIST_RDLOCK(&mwi_subs);
-	AST_RWLIST_TRAVERSE(&mwi_subs, mwi_sub, entry) {
-		if (!ast_strlen_zero(mwi_sub->mailbox)) {
-			if (
-				/* First case: everything matches */
-				(ast_strlen_zero(context) && ast_strlen_zero(mailbox)) ||
-				/* Second case: match the mailbox only */
-				(ast_strlen_zero(context) && !ast_strlen_zero(mailbox) &&
-					(at = strchr(mwi_sub->mailbox, '@')) &&
-					strncmp(mailbox, mwi_sub->mailbox, at - mwi_sub->mailbox) == 0) ||
-				/* Third case: match the context only */
-				(!ast_strlen_zero(context) && ast_strlen_zero(mailbox) &&
-					(at = strchr(mwi_sub->mailbox, '@')) &&
-					strcmp(context, at + 1) == 0) ||
-				/* Final case: match an exact specified mailbox */
-				(!ast_strlen_zero(context) && !ast_strlen_zero(mailbox) &&
-					(at = strchr(mwi_sub->mailbox, '@')) &&
-					strncmp(mailbox, mwi_sub->mailbox, at - mwi_sub->mailbox) == 0 &&
-					strcmp(context, at + 1) == 0)
+	if (!ast_strlen_zero(mwi_state->uniqueid)) {
+		if (
+			/* First case: everything matches */
+			(ast_strlen_zero(context) && ast_strlen_zero(mailbox)) ||
+			/* Second case: match the mailbox only */
+			(ast_strlen_zero(context) && !ast_strlen_zero(mailbox) &&
+			 (at = strchr(mwi_state->uniqueid, '@')) &&
+			 strncmp(mailbox, mwi_state->uniqueid, at - mwi_state->uniqueid) == 0) ||
+			/* Third case: match the context only */
+			(!ast_strlen_zero(context) && ast_strlen_zero(mailbox) &&
+			 (at = strchr(mwi_state->uniqueid, '@')) &&
+			 strcmp(context, at + 1) == 0) ||
+			/* Final case: match an exact specified mailbox */
+			(!ast_strlen_zero(context) && !ast_strlen_zero(mailbox) &&
+			 (at = strchr(mwi_state->uniqueid, '@')) &&
+			 strncmp(mailbox, mwi_state->uniqueid, at - mwi_state->uniqueid) == 0 &&
+			 strcmp(context, at + 1) == 0)
 			) {
-				poll_subscribed_mailbox(mwi_sub);
-			}
+			poll_subscribed_mailbox(mwi_state, NULL);
 		}
 	}
-	AST_RWLIST_UNLOCK(&mwi_subs);
+
+	return 0;
+}
+
+static int manager_voicemail_refresh(struct mansession *s, const struct message *m)
+{
+	ast_mwi_state_callback_all(manager_match_mailbox, (void *)m);
 	astman_send_ack(s, m, "Refresh sent");
 	return RESULT_SUCCESS;
 }
@@ -13943,7 +13812,7 @@ static int actual_load_config(int reload, struct ast_config *cfg, struct ast_con
 	strcpy(listen_control_stop_key, DEFAULT_LISTEN_CONTROL_STOP_KEY);
 
 #ifdef IMAP_STORAGE
-	imap_close_subscribed_mailboxes();
+	ast_mwi_state_callback_all(imap_close_subscribed_mailbox, NULL);
 #endif
 
 	/* Free all the users structure */
@@ -15326,7 +15195,7 @@ static int unload_module(void)
 	ast_unload_realtime("voicemail_data");
 
 #ifdef IMAP_STORAGE
-	imap_close_subscribed_mailboxes();
+	ast_mwi_state_callback_all(imap_close_subscribed_mailbox, NULL);
 #endif
 	free_vm_users();
 	free_vm_zones();