diff --git a/tests/posix/common/src/mutex_attr.c b/tests/posix/common/src/mutex_attr.c
index 2ecda40ae58..d5f70083d41 100644
--- a/tests/posix/common/src/mutex_attr.c
+++ b/tests/posix/common/src/mutex_attr.c
@@ -43,64 +43,4 @@ ZTEST(mutex_attr, test_pthread_mutexattr_destroy)
 	}
 }
 
-ZTEST(mutex_attr, test_pthread_mutexattr_gettype)
-{
-	int type;
-	pthread_mutexattr_t attr;
-
-	/* degenerate cases */
-	{
-		if (false) {
-			/* undefined behaviour */
-			zassert_equal(EINVAL, pthread_mutexattr_gettype(&attr, &type));
-		}
-		zassert_equal(EINVAL, pthread_mutexattr_gettype(NULL, NULL));
-		zassert_equal(EINVAL, pthread_mutexattr_gettype(NULL, &type));
-		zassert_equal(EINVAL, pthread_mutexattr_gettype(&attr, NULL));
-	}
-
-	zassert_ok(pthread_mutexattr_init(&attr));
-	zassert_ok(pthread_mutexattr_gettype(&attr, &type));
-	zassert_equal(type, PTHREAD_MUTEX_DEFAULT);
-	zassert_ok(pthread_mutexattr_destroy(&attr));
-}
-
-ZTEST(mutex_attr, test_pthread_mutexattr_settype)
-{
-	int type;
-	pthread_mutexattr_t attr;
-
-	/* degenerate cases */
-	{
-		if (false) {
-			/* undefined behaviour */
-			zassert_equal(EINVAL,
-				      pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_DEFAULT));
-		}
-		zassert_equal(EINVAL, pthread_mutexattr_settype(NULL, 42));
-		zassert_equal(EINVAL, pthread_mutexattr_settype(NULL, PTHREAD_MUTEX_NORMAL));
-		zassert_equal(EINVAL, pthread_mutexattr_settype(&attr, 42));
-	}
-
-	zassert_ok(pthread_mutexattr_init(&attr));
-
-	zassert_ok(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_DEFAULT));
-	zassert_ok(pthread_mutexattr_gettype(&attr, &type));
-	zassert_equal(type, PTHREAD_MUTEX_DEFAULT);
-
-	zassert_ok(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_NORMAL));
-	zassert_ok(pthread_mutexattr_gettype(&attr, &type));
-	zassert_equal(type, PTHREAD_MUTEX_NORMAL);
-
-	zassert_ok(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE));
-	zassert_ok(pthread_mutexattr_gettype(&attr, &type));
-	zassert_equal(type, PTHREAD_MUTEX_RECURSIVE);
-
-	zassert_ok(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK));
-	zassert_ok(pthread_mutexattr_gettype(&attr, &type));
-	zassert_equal(type, PTHREAD_MUTEX_ERRORCHECK);
-
-	zassert_ok(pthread_mutexattr_destroy(&attr));
-}
-
 ZTEST_SUITE(mutex_attr, NULL, NULL, NULL, NULL, NULL);
diff --git a/tests/posix/common/src/pthread_attr.c b/tests/posix/common/src/pthread_attr.c
index 6d48acb7f7b..dfeb1b48992 100644
--- a/tests/posix/common/src/pthread_attr.c
+++ b/tests/posix/common/src/pthread_attr.c
@@ -147,56 +147,6 @@ ZTEST(pthread_attr, test_pthread_attr_init_destroy)
 	/* note: attr is still valid and is destroyed in after() */
 }
 
-ZTEST(pthread_attr, test_pthread_attr_getguardsize)
-{
-	size_t guardsize;
-
-	/* degenerate cases */
-	{
-		if (false) {
-			/* undefined behaviour */
-			zassert_equal(pthread_attr_getguardsize(NULL, NULL), EINVAL);
-			zassert_equal(pthread_attr_getguardsize(NULL, &guardsize), EINVAL);
-			zassert_equal(pthread_attr_getguardsize(&uninit_attr, &guardsize), EINVAL);
-		}
-		zassert_equal(pthread_attr_getguardsize(&attr, NULL), EINVAL);
-	}
-
-	guardsize = BIOS_FOOD;
-	zassert_ok(pthread_attr_getguardsize(&attr, &guardsize));
-	zassert_not_equal(guardsize, BIOS_FOOD);
-}
-
-ZTEST(pthread_attr, test_pthread_attr_setguardsize)
-{
-	size_t guardsize = CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_DEFAULT;
-	size_t sizes[] = {0, BIT_MASK(CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_BITS / 2),
-			  BIT_MASK(CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_BITS)};
-
-	/* valid value */
-	zassert_ok(pthread_attr_getguardsize(&attr, &guardsize));
-
-	/* degenerate cases */
-	{
-		if (false) {
-			/* undefined behaviour */
-			zassert_equal(pthread_attr_setguardsize(NULL, SIZE_MAX), EINVAL);
-			zassert_equal(pthread_attr_setguardsize(NULL, guardsize), EINVAL);
-			zassert_equal(pthread_attr_setguardsize((pthread_attr_t *)&uninit_attr,
-								guardsize),
-				      EINVAL);
-		}
-		zassert_equal(pthread_attr_setguardsize(&attr, SIZE_MAX), EINVAL);
-	}
-
-	ARRAY_FOR_EACH(sizes, i) {
-		zassert_ok(pthread_attr_setguardsize(&attr, sizes[i]));
-		guardsize = ~sizes[i];
-		zassert_ok(pthread_attr_getguardsize(&attr, &guardsize));
-		zassert_equal(guardsize, sizes[i]);
-	}
-}
-
 ZTEST(pthread_attr, test_pthread_attr_getschedparam)
 {
 	struct sched_param param = {
diff --git a/tests/posix/threads_ext/CMakeLists.txt b/tests/posix/threads_ext/CMakeLists.txt
new file mode 100644
index 00000000000..2c3e19d4647
--- /dev/null
+++ b/tests/posix/threads_ext/CMakeLists.txt
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(posix_threads_ext)
+
+target_sources(app PRIVATE src/main.c)
+
+target_compile_options(app PRIVATE -U_POSIX_C_SOURCE -D_POSIX_C_SOURCE=200809L)
diff --git a/tests/posix/threads_ext/prj.conf b/tests/posix/threads_ext/prj.conf
new file mode 100644
index 00000000000..dd28c46e49f
--- /dev/null
+++ b/tests/posix/threads_ext/prj.conf
@@ -0,0 +1,5 @@
+CONFIG_POSIX_API=y
+
+CONFIG_ZTEST=y
+CONFIG_POSIX_AEP_CHOICE_BASE=y
+CONFIG_POSIX_THREADS_EXT=y
diff --git a/tests/posix/threads_ext/src/main.c b/tests/posix/threads_ext/src/main.c
new file mode 100644
index 00000000000..eb01ec6843e
--- /dev/null
+++ b/tests/posix/threads_ext/src/main.c
@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2024, Meta
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <pthread.h>
+
+#include <zephyr/sys/util.h>
+#include <zephyr/ztest.h>
+
+#define BIOS_FOOD           0xB105F00D
+#define SCHED_INVALID       4242
+#define INVALID_DETACHSTATE 7373
+
+static bool attr_valid;
+static pthread_attr_t attr;
+static const pthread_attr_t uninit_attr;
+
+ZTEST(posix_threads_ext, test_pthread_attr_getguardsize)
+{
+	size_t guardsize;
+
+	/* degenerate cases */
+	{
+		if (false) {
+			/* undefined behaviour */
+			zassert_equal(pthread_attr_getguardsize(NULL, NULL), EINVAL);
+			zassert_equal(pthread_attr_getguardsize(NULL, &guardsize), EINVAL);
+			zassert_equal(pthread_attr_getguardsize(&uninit_attr, &guardsize), EINVAL);
+		}
+		zassert_equal(pthread_attr_getguardsize(&attr, NULL), EINVAL);
+	}
+
+	guardsize = BIOS_FOOD;
+	zassert_ok(pthread_attr_getguardsize(&attr, &guardsize));
+	zassert_not_equal(guardsize, BIOS_FOOD);
+}
+
+ZTEST(posix_threads_ext, test_pthread_attr_setguardsize)
+{
+	size_t guardsize = CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_DEFAULT;
+	size_t sizes[] = {0, BIT_MASK(CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_BITS / 2),
+			  BIT_MASK(CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_BITS)};
+
+	/* valid value */
+	zassert_ok(pthread_attr_getguardsize(&attr, &guardsize));
+
+	/* degenerate cases */
+	{
+		if (false) {
+			/* undefined behaviour */
+			zassert_equal(pthread_attr_setguardsize(NULL, SIZE_MAX), EINVAL);
+			zassert_equal(pthread_attr_setguardsize(NULL, guardsize), EINVAL);
+			zassert_equal(pthread_attr_setguardsize((pthread_attr_t *)&uninit_attr,
+								guardsize),
+				      EINVAL);
+		}
+		zassert_equal(pthread_attr_setguardsize(&attr, SIZE_MAX), EINVAL);
+	}
+
+	ARRAY_FOR_EACH(sizes, i) {
+		zassert_ok(pthread_attr_setguardsize(&attr, sizes[i]));
+		guardsize = ~sizes[i];
+		zassert_ok(pthread_attr_getguardsize(&attr, &guardsize));
+		zassert_equal(guardsize, sizes[i]);
+	}
+}
+
+ZTEST(posix_threads_ext, test_pthread_mutexattr_gettype)
+{
+	int type;
+	pthread_mutexattr_t attr;
+
+	/* degenerate cases */
+	{
+		if (false) {
+			/* undefined behaviour */
+			zassert_equal(EINVAL, pthread_mutexattr_gettype(&attr, &type));
+		}
+		zassert_equal(EINVAL, pthread_mutexattr_gettype(NULL, NULL));
+		zassert_equal(EINVAL, pthread_mutexattr_gettype(NULL, &type));
+		zassert_equal(EINVAL, pthread_mutexattr_gettype(&attr, NULL));
+	}
+
+	zassert_ok(pthread_mutexattr_init(&attr));
+	zassert_ok(pthread_mutexattr_gettype(&attr, &type));
+	zassert_equal(type, PTHREAD_MUTEX_DEFAULT);
+	zassert_ok(pthread_mutexattr_destroy(&attr));
+}
+
+ZTEST(posix_threads_ext, test_pthread_mutexattr_settype)
+{
+	int type;
+	pthread_mutexattr_t attr;
+
+	/* degenerate cases */
+	{
+		if (false) {
+			/* undefined behaviour */
+			zassert_equal(EINVAL,
+				      pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_DEFAULT));
+		}
+		zassert_equal(EINVAL, pthread_mutexattr_settype(NULL, 42));
+		zassert_equal(EINVAL, pthread_mutexattr_settype(NULL, PTHREAD_MUTEX_NORMAL));
+		zassert_equal(EINVAL, pthread_mutexattr_settype(&attr, 42));
+	}
+
+	zassert_ok(pthread_mutexattr_init(&attr));
+
+	zassert_ok(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_DEFAULT));
+	zassert_ok(pthread_mutexattr_gettype(&attr, &type));
+	zassert_equal(type, PTHREAD_MUTEX_DEFAULT);
+
+	zassert_ok(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_NORMAL));
+	zassert_ok(pthread_mutexattr_gettype(&attr, &type));
+	zassert_equal(type, PTHREAD_MUTEX_NORMAL);
+
+	zassert_ok(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE));
+	zassert_ok(pthread_mutexattr_gettype(&attr, &type));
+	zassert_equal(type, PTHREAD_MUTEX_RECURSIVE);
+
+	zassert_ok(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK));
+	zassert_ok(pthread_mutexattr_gettype(&attr, &type));
+	zassert_equal(type, PTHREAD_MUTEX_ERRORCHECK);
+
+	zassert_ok(pthread_mutexattr_destroy(&attr));
+}
+
+static void before(void *arg)
+{
+	ARG_UNUSED(arg);
+
+	zassert_ok(pthread_attr_init(&attr));
+	/* TODO: pthread_attr_init() should be sufficient to initialize a thread by itself */
+	/* zassert_ok(pthread_attr_setstack(&attr, &static_thread_stack, STATIC_THREAD_STACK_SIZE));
+	 */
+	attr_valid = true;
+}
+
+static void after(void *arg)
+{
+	ARG_UNUSED(arg);
+
+	if (attr_valid) {
+		(void)pthread_attr_destroy(&attr);
+		attr_valid = false;
+	}
+}
+
+ZTEST_SUITE(posix_threads_ext, NULL, NULL, before, after, NULL);
diff --git a/tests/posix/threads_ext/testcase.yaml b/tests/posix/threads_ext/testcase.yaml
new file mode 100644
index 00000000000..b8e1966a32b
--- /dev/null
+++ b/tests/posix/threads_ext/testcase.yaml
@@ -0,0 +1,25 @@
+common:
+  filter: not CONFIG_NATIVE_LIBC
+  tags:
+    - posix
+    - threads_ext
+  # 1 tier0 platform per supported architecture
+  platform_key:
+    - arch
+    - simulation
+tests:
+  portability.posix.threads_ext:
+    min_flash: 64
+    min_ram: 32
+  portability.posix.threads_ext.minimal:
+    extra_configs:
+      - CONFIG_MINIMAL_LIBC=y
+  portability.posix.threads_ext.newlib:
+    filter: TOOLCHAIN_HAS_NEWLIB == 1
+    extra_configs:
+      - CONFIG_NEWLIB_LIBC=y
+  portability.posix.threads_ext.picolibc:
+    tags: picolibc
+    filter: CONFIG_PICOLIBC_SUPPORTED
+    extra_configs:
+      - CONFIG_PICOLIBC=y