diff --git a/net/base/net_errors.h b/net/base/net_errors.h
index ee679fb1b631..c9e7fdf24fdd 100644
--- a/net/base/net_errors.h
+++ b/net/base/net_errors.h
@@ -12,7 +12,11 @@
 #include "base/logging.h"
 #include "net/base/net_export.h"
 #if defined(STARBOARD)
+#if SB_API_VERSION < 16
 #include "starboard/common/socket.h"
+#else
+#include <errno.h>
+#endif
 #include "starboard/system.h"
 #endif
 
@@ -57,6 +61,8 @@ NET_EXPORT bool IsDnsError(int error);
 NET_EXPORT Error MapSystemError(logging::SystemErrorCode os_error);
 
 #if defined(STARBOARD)
+
+#if SB_API_VERSION < 16
 // Map socket error code to Error.
 NET_EXPORT Error MapSocketError(SbSocketError error);
 
@@ -64,6 +70,7 @@ NET_EXPORT Error MapSocketError(SbSocketError error);
 static SB_C_INLINE Error MapLastSocketError(SbSocket socket) {
   return MapSocketError(SbSocketGetLastError(socket));
 }
+#endif  // SB_API_VERSION < 16
 
 // Gets the last system error as a net error.
 static SB_C_INLINE Error MapLastSystemError() {
diff --git a/net/base/net_errors_starboard.cc b/net/base/net_errors_starboard.cc
index 3eabf3b39360..99bc994fb58e 100644
--- a/net/base/net_errors_starboard.cc
+++ b/net/base/net_errors_starboard.cc
@@ -36,6 +36,7 @@ Error MapSystemError(logging::SystemErrorCode error) {
   return ERR_FAILED;
 }
 
+#if SB_API_VERSION < 16
 Error MapSocketError(SbSocketError error) {
   if (error != kSbSocketOk)
     DVLOG(2) << "Error " << error;
@@ -55,5 +56,6 @@ Error MapSocketError(SbSocketError error) {
       return ERR_FAILED;
   }
 }
+#endif  // SB_API_VERSION < 16
 
 }  // namespace net
diff --git a/net/socket/tcp_socket_starboard.cc b/net/socket/tcp_socket_starboard.cc
index 21a0091d02e5..70f29b8aad3f 100644
--- a/net/socket/tcp_socket_starboard.cc
+++ b/net/socket/tcp_socket_starboard.cc
@@ -16,6 +16,8 @@
 
 #include <memory>
 #include <utility>
+#include <netinet/in.h>
+#include <sys/socket.h>
 
 #include "base/callback_helpers.h"
 #include "base/time/time.h"
@@ -24,6 +26,8 @@
 #include "net/socket/socket_net_log_params.h"
 #include "net/socket/socket_options.h"
 #include "starboard/configuration_constants.h"
+#include "starboard/socket.h"
+
 
 namespace net {
 
@@ -50,7 +54,16 @@ TCPSocketStarboard::~TCPSocketStarboard() {
 int TCPSocketStarboard::Open(AddressFamily family) {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
   DCHECK(!SbSocketIsValid(socket_));
+#if SB_API_VERSION < 16
   socket_ = SbSocketCreate(ConvertAddressFamily(family), kSbSocketProtocolTcp);
+#else
+  int socket_fd = socket(family, SOCK_STREAM, IPPROTO_TCP);
+  if (socket_fd < 0) {
+    socket_= kSbSocketInvalid;
+  } else {
+    socket_ = new SbSocketWrapper(ConvertAddressFamily(family), kSbSocketProtocolTcp, socket_fd);
+  }
+#endif
   if (!SbSocketIsValid(socket_)) {
     return MapLastSystemError();
   }
@@ -98,7 +111,11 @@ int TCPSocketStarboard::Bind(const IPEndPoint& address) {
   SbSocketError error = SbSocketBind(socket_, &storage);
   if (error != kSbSocketOk) {
     DLOG(ERROR) << "SbSocketBind() returned an error";
+#if SB_API_VERSION < 16
     return MapLastSocketError(socket_);
+#else
+    return errno;
+#endif
   }
 
   local_address_.reset(new IPEndPoint(address));
@@ -115,7 +132,11 @@ int TCPSocketStarboard::Listen(int backlog) {
   SbSocketError error = SbSocketListen(socket_);
   if (error != kSbSocketOk) {
     DLOG(ERROR) << "SbSocketListen() returned an error";
+#if SB_API_VERSION < 16
     int rv = MapLastSocketError(socket_);
+#else
+    int rv = errno;
+#endif
     Close();
     return rv;
   }
@@ -142,7 +163,11 @@ int TCPSocketStarboard::Accept(std::unique_ptr<TCPSocketStarboard>* socket,
             socket_, true, base::MessageLoopCurrentForIO::WATCH_READ,
             &socket_watcher_, this)) {
       DLOG(ERROR) << "WatchSocket failed on read";
+#if SB_API_VERSION < 16
       return MapLastSocketError(socket_);
+#else
+      return errno;
+#endif
     }
 
     accept_socket_ = socket;
@@ -156,7 +181,11 @@ int TCPSocketStarboard::Accept(std::unique_ptr<TCPSocketStarboard>* socket,
 int TCPSocketStarboard::SetDefaultOptionsForServer() {
   DCHECK(SbSocketIsValid(socket_));
   if (!SbSocketSetReuseAddress(socket_, true)) {
+#if SB_API_VERSION < 16
     return MapLastSocketError(socket_);
+#else
+    return errno;
+#endif
   }
   return OK;
 }
@@ -177,9 +206,20 @@ void TCPSocketStarboard::SetDefaultOptionsForClient() {
 int TCPSocketStarboard::AcceptInternal(
     std::unique_ptr<TCPSocketStarboard>* socket,
     IPEndPoint* address) {
-  SbSocket new_socket = SbSocketAccept(socket_);
+  SbSocket new_socket;
+#if SB_API_VERSION < 16
+  new_socket = SbSocketAccept(socket_);
   if (!SbSocketIsValid(new_socket)) {
     int net_error = MapLastSocketError(socket_);
+#else
+  if(!SbSocketIsValid(socket_)) {
+    return errno;
+  }
+  new_socket->socket_fd = accept(socket_->socket_fd, NULL, NULL);
+  if (new_socket->socket_fd < 0) {
+    int net_error = errno;
+    socket_->error = TranslateSocketErrnoToSbError(errno);
+#endif
     if (net_error != ERR_IO_PENDING) {
       net_log_.EndEventWithNetErrorCode(NetLogEventType::TCP_ACCEPT, net_error);
     }
@@ -191,7 +231,11 @@ int TCPSocketStarboard::AcceptInternal(
   // We use ReceiveFrom to get peer address of the newly connected socket.
   int received = SbSocketReceiveFrom(new_socket, &unused_byte, 0, &sb_address);
   if (received != 0) {
+#if SB_API_VERSION < 16
     int net_error = MapLastSocketError(new_socket);
+#else
+    int net_error = errno;
+#endif
     if (net_error != OK && net_error != ERR_IO_PENDING) {
       SbSocketDestroy(new_socket);
       net_log_.EndEventWithNetErrorCode(NetLogEventType::TCP_ACCEPT, net_error);
@@ -312,7 +356,9 @@ void TCPSocketStarboard::OnSocketReadyToWrite(SbSocket socket) {
 int TCPSocketStarboard::Connect(const IPEndPoint& address,
                                 CompletionOnceCallback callback) {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+
   DCHECK(SbSocketIsValid(socket_));
+
   DCHECK(!peer_address_);
   DCHECK(!connect_pending());
 
@@ -330,9 +376,35 @@ int TCPSocketStarboard::Connect(const IPEndPoint& address,
 
   peer_address_.reset(new IPEndPoint(address));
 
+#if SB_API_VERSION < 16
   SbSocketError result = SbSocketConnect(socket_, &storage);
-
   int rv = MapLastSocketError(socket_);
+#else
+  SockAddr sock_addr;
+  if (!sock_addr.FromSbSocketAddress(&storage)) {
+    SB_DLOG(ERROR) << __FUNCTION__ << ": Invalid address";
+    return errno;
+  }
+  SB_DCHECK(socket_->socket_fd >= 0);
+  if (storage.type != socket_->address_type) {
+    SB_DLOG(ERROR) << __FUNCTION__ << ": Incompatible addresses: "
+                   << "socket type = " << socket_->address_type
+                   << ", argument type = " << storage.type;
+    return (int)kSbSocketErrorFailed;
+  }
+  int result = HANDLE_EINTR_WRAPPER(
+      connect(socket_->socket_fd, sock_addr.sockaddr(), sock_addr.length));
+  if (result != 0 && errno == EINPROGRESS) {
+    return errno;
+  }
+
+  if (result != 0) {
+    SB_DLOG(ERROR) << __FUNCTION__ << ": connect failed: " << errno;
+    return errno;
+  }
+
+  int rv = errno;
+#endif
   if (rv != ERR_IO_PENDING) {
     return HandleConnectCompleted(rv);
   }
@@ -502,10 +574,17 @@ int TCPSocketStarboard::DoRead(IOBuffer* buf, int buf_len) {
     return bytes_read;
   } else {
     // If |bytes_read| < 0, some kind of error occurred.
+#if SB_API_VERSION < 16
     SbSocketError starboard_error = SbSocketGetLastError(socket_);
     int rv = MapSocketError(starboard_error);
     net_log_.AddEvent(NetLogEventType::SOCKET_READ_ERROR,
                       CreateNetLogSocketErrorCallback(rv, starboard_error));
+#else
+    int rv = errno;
+    net_log_.AddEvent(NetLogEventType::SOCKET_READ_ERROR,
+                      CreateNetLogSocketErrorCallback(rv, errno));
+#endif
+
     if (rv != ERR_IO_PENDING) {
       DLOG(ERROR) << __FUNCTION__ << "[" << this << "]: Error: " << rv;
     }
@@ -559,10 +638,16 @@ int TCPSocketStarboard::DoWrite(IOBuffer* buf, int buf_len) {
 
     return bytes_sent;
   } else {
+#if SB_API_VERSION < 16
     SbSocketError starboard_error = SbSocketGetLastError(socket_);
     int rv = MapSocketError(starboard_error);
     net_log_.AddEvent(NetLogEventType::SOCKET_WRITE_ERROR,
                       CreateNetLogSocketErrorCallback(rv, starboard_error));
+#else
+    int rv = errno;
+    net_log_.AddEvent(NetLogEventType::SOCKET_WRITE_ERROR,
+                      CreateNetLogSocketErrorCallback(rv, errno));
+#endif
     if (rv != ERR_IO_PENDING) {
       DLOG(ERROR) << __FUNCTION__ << "[" << this << "]: Error: " << rv;
     }
@@ -620,8 +705,12 @@ int TCPSocketStarboard::GetLocalAddress(IPEndPoint* address) const {
 
   SbSocketAddress sb_address;
   if (!SbSocketGetLocalAddress(socket_, &sb_address)) {
+#if SB_API_VERSION < 16
     SbSocketError starboard_error = SbSocketGetLastError(socket_);
     return MapSocketError(starboard_error);
+#else
+    return errno;
+#endif
   }
 
   if (!address->FromSbSocketAddress(&sb_address)) {
diff --git a/net/socket/udp_socket_starboard.cc b/net/socket/udp_socket_starboard.cc
index 3abdcef2824d..7bd880c3d339 100644
--- a/net/socket/udp_socket_starboard.cc
+++ b/net/socket/udp_socket_starboard.cc
@@ -122,7 +122,11 @@ int UDPSocketStarboard::GetLocalAddress(IPEndPoint* address) const {
   if (!local_address_.get()) {
     SbSocketAddress address;
     if (!SbSocketGetLocalAddress(socket_, &address))
+#if SB_API_VERSION < 16
       return MapLastSocketError(socket_);
+#else
+      return errno;
+#endif
     std::unique_ptr<IPEndPoint> endpoint(new IPEndPoint());
     if (!endpoint->FromSbSocketAddress(&address))
       return ERR_FAILED;
@@ -158,7 +162,11 @@ int UDPSocketStarboard::RecvFrom(IOBuffer* buf,
           socket_, true, base::MessageLoopCurrentForIO::WATCH_READ,
           &socket_watcher_, this)) {
     PLOG(ERROR) << "WatchSocket failed on read";
+#if SB_API_VERSION < 16
     Error result = MapLastSocketError(socket_);
+#else
+    int result = errno;
+#endif
     if (result == ERR_IO_PENDING) {
       // Watch(...) might call SbSocketWaiterAdd() which does not guarantee
       // setting system error on failure, but we need to treat this as an
@@ -209,9 +217,15 @@ int UDPSocketStarboard::SendToOrWrite(IOBuffer* buf,
   if (!base::MessageLoopForIO::current()->Watch(
           socket_, true, base::MessageLoopCurrentForIO::WATCH_WRITE,
           &socket_watcher_, this)) {
+#if SB_API_VERSION < 16
     DVLOG(1) << "Watch failed on write, error "
              << SbSocketGetLastError(socket_);
     Error result = MapLastSocketError(socket_);
+#else
+    DVLOG(1) << "Watch failed on write, error "
+             << errno;
+    int result = errno;
+#endif
     LogWrite(result, NULL, NULL);
     return result;
   }
@@ -284,10 +298,18 @@ int UDPSocketStarboard::SetReceiveBufferSize(int32_t size) {
 
   int result = OK;
   if (!SbSocketSetReceiveBufferSize(socket_, size)) {
+#if SB_API_VERSION < 16
     result = MapLastSocketError(socket_);
+#else
+    result =errno;
+#endif
   }
   DCHECK_EQ(result, OK) << "Could not " << __FUNCTION__ << ": "
+#if SB_API_VERSION < 16
                         << SbSocketGetLastError(socket_);
+#else
+                        << errno;
+#endif
   return result;
 }
 
@@ -297,10 +319,18 @@ int UDPSocketStarboard::SetSendBufferSize(int32_t size) {
 
   int result = OK;
   if (!SbSocketSetSendBufferSize(socket_, size)) {
+#if SB_API_VERSION < 16
     result = MapLastSocketError(socket_);
+#else
+    result = errno;
+#endif
   }
   DCHECK_EQ(result, OK) << "Could not " << __FUNCTION__ << ": "
+#if SB_API_VERSION < 16
                         << SbSocketGetLastError(socket_);
+#else
+                        << errno;
+#endif
   return result;
 }
 
@@ -435,7 +465,11 @@ int UDPSocketStarboard::InternalRecvFrom(IOBuffer* buf,
       result = ERR_ADDRESS_INVALID;
     }
   } else {
+#if SB_API_VERSION < 16
     result = MapLastSocketError(socket_);
+#else
+    result = errno;
+#endif
   }
 
   if (result != ERR_IO_PENDING) {
@@ -463,8 +497,11 @@ int UDPSocketStarboard::InternalSendTo(IOBuffer* buf,
   int result = SbSocketSendTo(socket_, buf->data(), buf_len, &sb_address);
 
   if (result < 0)
+#if SB_API_VERSION < 16
     result = MapLastSocketError(socket_);
-
+#else
+    result = errno;
+#endif
   if (result != ERR_IO_PENDING)
     LogWrite(result, buf->data(), address);
 
@@ -497,7 +534,11 @@ int UDPSocketStarboard::JoinGroup(const IPAddress& group_address) const {
 
   if (!SbSocketJoinMulticastGroup(socket_, &sb_address)) {
     LOG(WARNING) << "SbSocketJoinMulticastGroup failed on UDP socket.";
+#if SB_API_VERSION < 16
     return MapLastSocketError(socket_);
+#else
+    return errno;
+#endif
   }
   return OK;
 }
@@ -571,7 +612,11 @@ SendResult UDPSocketStarboardSender::InternalSendBuffers(
   for (auto& buffer : buffers) {
     int result = Send(socket, buffer->data(), buffer->length(), address);
     if (result < 0) {
+#if SB_API_VERSION < 16
       rv = MapLastSocketError(socket);
+#else
+      rv = errno;
+#endif
       break;
     }
     write_count++;
@@ -774,7 +819,11 @@ void UDPSocketStarboard::DidSendBuffers(SendResult send_result) {
   if (last_async_result_ == ERR_IO_PENDING) {
     DVLOG(2) << __func__ << " WatchSocket start";
     if (!WatchSocket()) {
+#if SB_API_VERSION < 16
       last_async_result_ = MapLastSocketError(socket_);
+#else
+      last_async_result_ = errno;
+#endif
       DVLOG(1) << "WatchSocket failed on write, error: " << last_async_result_;
       LogWrite(last_async_result_, NULL, NULL);
     } else {
diff --git a/starboard/android/shared/BUILD.gn b/starboard/android/shared/BUILD.gn
index 2cfd29c7db6a..c73ed596e190 100644
--- a/starboard/android/shared/BUILD.gn
+++ b/starboard/android/shared/BUILD.gn
@@ -115,7 +115,6 @@ static_library("starboard_platform") {
     "//starboard/shared/posix/set_non_blocking_internal.cc",
     "//starboard/shared/posix/socket_accept.cc",
     "//starboard/shared/posix/socket_bind.cc",
-    "//starboard/shared/posix/socket_clear_last_error.cc",
     "//starboard/shared/posix/socket_connect.cc",
     "//starboard/shared/posix/socket_create.cc",
     "//starboard/shared/posix/socket_destroy.cc",
diff --git a/starboard/common/socket.cc b/starboard/common/socket.cc
index ae861168357b..90432407a08c 100644
--- a/starboard/common/socket.cc
+++ b/starboard/common/socket.cc
@@ -14,10 +14,12 @@
 
 #include "starboard/common/socket.h"
 
+#include <errno.h>
 #include <iomanip>
 
 #include "starboard/common/log.h"
 #include "starboard/configuration.h"
+#include "starboard/shared/modular/posix_socket_wrappers.h"
 
 namespace starboard {
 
@@ -105,11 +107,19 @@ bool Socket::IsPending() {
 }
 
 SbSocketError Socket::GetLastError() {
+#if SB_API_VERSION < 16
   return SbSocketGetLastError(socket_);
+#else
+  return socket_->error;
+#endif
 }
 
 void Socket::ClearLastError() {
+#if SB_API_VERSION < 16
   SbSocketClearLastError(socket_);
+#else
+  socket_->socket_fd = kSbSocketOk;
+#endif
 }
 
 int Socket::ReceiveFrom(char* out_data,
diff --git a/starboard/common/socket.h b/starboard/common/socket.h
index 8efaadaf22cb..661a8fae1496 100644
--- a/starboard/common/socket.h
+++ b/starboard/common/socket.h
@@ -24,6 +24,9 @@
 
 #include "starboard/socket.h"
 #include "starboard/types.h"
+#if SB_API_VERSION >= 16
+#include "starboard/shared/modular/posix_socket_wrappers.h"
+#endif
 
 namespace starboard {
 
diff --git a/starboard/elf_loader/exported_symbols.cc b/starboard/elf_loader/exported_symbols.cc
index c4a9740d8b84..ca9d10c5065a 100644
--- a/starboard/elf_loader/exported_symbols.cc
+++ b/starboard/elf_loader/exported_symbols.cc
@@ -268,13 +268,11 @@ ExportedSymbols::ExportedSymbols() {
 #endif  // SB_API_VERSION >= 15
   REGISTER_SYMBOL(SbSocketAccept);
   REGISTER_SYMBOL(SbSocketBind);
-  REGISTER_SYMBOL(SbSocketClearLastError);
   REGISTER_SYMBOL(SbSocketConnect);
   REGISTER_SYMBOL(SbSocketCreate);
   REGISTER_SYMBOL(SbSocketDestroy);
   REGISTER_SYMBOL(SbSocketFreeResolution);
   REGISTER_SYMBOL(SbSocketGetInterfaceAddress);
-  REGISTER_SYMBOL(SbSocketGetLastError);
   REGISTER_SYMBOL(SbSocketGetLocalAddress);
   REGISTER_SYMBOL(SbSocketIsConnected);
   REGISTER_SYMBOL(SbSocketIsConnectedAndIdle);
@@ -314,6 +312,8 @@ ExportedSymbols::ExportedSymbols() {
   REGISTER_SYMBOL(SbStringFormat);
   REGISTER_SYMBOL(SbStringFormatWide);
   REGISTER_SYMBOL(SbStringScan);
+  REGISTER_SYMBOL(SbSocketClearLastError);
+  REGISTER_SYMBOL(SbSocketGetLastError);
 #endif  // SB_API_VERSION < 16
   REGISTER_SYMBOL(SbSystemBreakIntoDebugger);
   REGISTER_SYMBOL(SbSystemClearLastError);
diff --git a/starboard/linux/shared/BUILD.gn b/starboard/linux/shared/BUILD.gn
index f46e0d1a5a9a..037cac380d0a 100644
--- a/starboard/linux/shared/BUILD.gn
+++ b/starboard/linux/shared/BUILD.gn
@@ -182,7 +182,6 @@ static_library("starboard_platform_sources") {
     "//starboard/shared/posix/set_non_blocking_internal.cc",
     "//starboard/shared/posix/socket_accept.cc",
     "//starboard/shared/posix/socket_bind.cc",
-    "//starboard/shared/posix/socket_clear_last_error.cc",
     "//starboard/shared/posix/socket_connect.cc",
     "//starboard/shared/posix/socket_create.cc",
     "//starboard/shared/posix/socket_destroy.cc",
diff --git a/starboard/nplb/socket_accept_test.cc b/starboard/nplb/socket_accept_test.cc
index be933db44e4f..e5277cf7421f 100644
--- a/starboard/nplb/socket_accept_test.cc
+++ b/starboard/nplb/socket_accept_test.cc
@@ -14,7 +14,7 @@
 
 // The accept SunnyDay case is tested as a subset of at least one other test
 // case, so it is not included redundantly here.
-
+#if SB_API_VERSION < 16
 #include "starboard/common/socket.h"
 #include "starboard/nplb/socket_helpers.h"
 #include "starboard/time.h"
@@ -92,3 +92,4 @@ INSTANTIATE_TEST_CASE_P(SbSocketAddressTypes,
 }  // namespace
 }  // namespace nplb
 }  // namespace starboard
+#endif
diff --git a/starboard/nplb/socket_clear_last_error_test.cc b/starboard/nplb/socket_clear_last_error_test.cc
index d21f8669d4ec..7c713d751c51 100644
--- a/starboard/nplb/socket_clear_last_error_test.cc
+++ b/starboard/nplb/socket_clear_last_error_test.cc
@@ -14,7 +14,7 @@
 
 // The Sunny Day test is used in several other tests as the way to detect if the
 // error is correct, so it is not repeated here.
-
+#if SB_API_VERSION < 16
 #include "starboard/common/socket.h"
 #include "starboard/nplb/socket_helpers.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -46,3 +46,4 @@ TEST(SbSocketClearLastErrorTest, RainyDayInvalidSocket) {
 }  // namespace
 }  // namespace nplb
 }  // namespace starboard
+#endif
diff --git a/starboard/nplb/socket_get_last_error_test.cc b/starboard/nplb/socket_get_last_error_test.cc
index afdd63a612eb..6d11c300927b 100644
--- a/starboard/nplb/socket_get_last_error_test.cc
+++ b/starboard/nplb/socket_get_last_error_test.cc
@@ -14,7 +14,7 @@
 
 // The Sunny Day test is used in several other tests as the way to detect if the
 // error is correct, so it is not repeated here.
-
+#if SB_API_VERSION < 16
 #include "starboard/common/socket.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -29,3 +29,4 @@ TEST(SbSocketGetLastErrorTest, RainyDayInvalidSocket) {
 }  // namespace
 }  // namespace nplb
 }  // namespace starboard
+#endif
diff --git a/starboard/nplb/socket_helpers.cc b/starboard/nplb/socket_helpers.cc
index 6efecd239fa7..550059ad3087 100644
--- a/starboard/nplb/socket_helpers.cc
+++ b/starboard/nplb/socket_helpers.cc
@@ -11,7 +11,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
-
+#if SB_API_VERSION < 16
 #include "starboard/nplb/socket_helpers.h"
 
 #include <utility>
@@ -637,3 +637,4 @@ std::string GetSbSocketAddressTypeProtocolPairName(
 
 }  // namespace nplb
 }  // namespace starboard
+#endif
diff --git a/starboard/nplb/socket_is_connected_test.cc b/starboard/nplb/socket_is_connected_test.cc
index 3c2bfdd9fe4f..424b84ee7993 100644
--- a/starboard/nplb/socket_is_connected_test.cc
+++ b/starboard/nplb/socket_is_connected_test.cc
@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#if SB_API_VERSION < 16
 #include <utility>
 
 #include "starboard/common/log.h"
@@ -72,6 +73,7 @@ TEST_P(SbSocketIsConnectedTest, SunnyDayNotConnected) {
 TEST_P(SbSocketIsConnectedTest, SunnyDayListeningNotConnected) {
   SbSocket server_socket =
       CreateListeningTcpSocket(GetAddressType(), GetPortNumberForTests());
+
   ASSERT_TRUE(SbSocketIsValid(server_socket));
   EXPECT_FALSE(SbSocketIsConnected(server_socket));
   EXPECT_TRUE(SbSocketDestroy(server_socket));
@@ -107,3 +109,5 @@ INSTANTIATE_TEST_CASE_P(
 }  // namespace
 }  // namespace nplb
 }  // namespace starboard
+
+#endif
diff --git a/starboard/nplb/socket_join_multicast_group_test.cc b/starboard/nplb/socket_join_multicast_group_test.cc
index f31fd0fcfc54..1dca2a607195 100644
--- a/starboard/nplb/socket_join_multicast_group_test.cc
+++ b/starboard/nplb/socket_join_multicast_group_test.cc
@@ -11,7 +11,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
-
+#if SB_API_VERSION < 16
 #include "starboard/common/socket.h"
 #include "starboard/nplb/socket_helpers.h"
 #include "starboard/thread.h"
@@ -123,3 +123,4 @@ TEST(SbSocketJoinMulticastGroupTest, RainyDayInvalidAddress) {
 }  // namespace
 }  // namespace nplb
 }  // namespace starboard
+#endif
diff --git a/starboard/nplb/socket_receive_from_test.cc b/starboard/nplb/socket_receive_from_test.cc
index b9deb062ac22..4a069be665fb 100644
--- a/starboard/nplb/socket_receive_from_test.cc
+++ b/starboard/nplb/socket_receive_from_test.cc
@@ -11,7 +11,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
-
+#if SB_API_VERSION < 16
 #include <utility>
 
 #include "starboard/common/socket.h"
@@ -146,3 +146,4 @@ INSTANTIATE_TEST_CASE_P(
 }  // namespace
 }  // namespace nplb
 }  // namespace starboard
+#endif
diff --git a/starboard/nplb/socket_send_to_test.cc b/starboard/nplb/socket_send_to_test.cc
index f0be4d56d065..c8fbae2e785a 100644
--- a/starboard/nplb/socket_send_to_test.cc
+++ b/starboard/nplb/socket_send_to_test.cc
@@ -14,7 +14,7 @@
 
 // SendTo is largely tested with ReceiveFrom, so look there for more involved
 // tests.
-
+#if SB_API_VERSION < 16
 #include <utility>
 
 #include "starboard/common/socket.h"
@@ -208,3 +208,4 @@ INSTANTIATE_TEST_CASE_P(
 }  // namespace
 }  // namespace nplb
 }  // namespace starboard
+#endif
diff --git a/starboard/nplb/socket_waiter_remove_test.cc b/starboard/nplb/socket_waiter_remove_test.cc
index 12c3627ec057..10e0c056c03e 100644
--- a/starboard/nplb/socket_waiter_remove_test.cc
+++ b/starboard/nplb/socket_waiter_remove_test.cc
@@ -11,6 +11,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+#if SB_API_VERSION < 16
 
 #include "starboard/common/socket.h"
 #include "starboard/nplb/socket_helpers.h"
@@ -94,3 +95,4 @@ INSTANTIATE_TEST_CASE_P(SbSocketAddressTypes,
 }  // namespace
 }  // namespace nplb
 }  // namespace starboard
+#endif
diff --git a/starboard/raspi/shared/BUILD.gn b/starboard/raspi/shared/BUILD.gn
index b7d3a5287eb4..6dbec366cc57 100644
--- a/starboard/raspi/shared/BUILD.gn
+++ b/starboard/raspi/shared/BUILD.gn
@@ -150,7 +150,6 @@ static_library("starboard_platform_sources") {
     "//starboard/shared/posix/set_non_blocking_internal.cc",
     "//starboard/shared/posix/socket_accept.cc",
     "//starboard/shared/posix/socket_bind.cc",
-    "//starboard/shared/posix/socket_clear_last_error.cc",
     "//starboard/shared/posix/socket_connect.cc",
     "//starboard/shared/posix/socket_create.cc",
     "//starboard/shared/posix/socket_destroy.cc",
diff --git a/starboard/shared/libevent/socket_waiter_internal.cc b/starboard/shared/libevent/socket_waiter_internal.cc
index 7ab3a4b3ad3c..21761039dfe2 100644
--- a/starboard/shared/libevent/socket_waiter_internal.cc
+++ b/starboard/shared/libevent/socket_waiter_internal.cc
@@ -56,7 +56,7 @@ SbSocket AcceptBySpinning(SbSocket server_socket, SbTime timeout) {
     }
 
     // If we didn't get a socket, it should be pending.
-    SB_DCHECK(SbSocketGetLastError(server_socket) == kSbSocketPending);
+    SB_DCHECK(server_socket->error == kSbSocketPending);
 
     // Check if we have passed our timeout.
     if (SbTimeGetMonotonicNow() - start >= timeout) {
diff --git a/starboard/shared/modular/BUILD.gn b/starboard/shared/modular/BUILD.gn
index 62bea7c5da78..19f57b07ecdc 100644
--- a/starboard/shared/modular/BUILD.gn
+++ b/starboard/shared/modular/BUILD.gn
@@ -16,6 +16,8 @@
 # symbol visibility issues for windows based modular platform builds.
 source_set("posix_time_wrappers") {
   sources = [
+    "posix_socket_wrappers.cc",
+    "posix_socket_wrappers.h",
     "posix_time_wrappers.cc",
     "posix_time_wrappers.h",
   ]
diff --git a/starboard/shared/modular/posix_socket_wrappers.cc b/starboard/shared/modular/posix_socket_wrappers.cc
new file mode 100644
index 000000000000..adf9f2f5c54f
--- /dev/null
+++ b/starboard/shared/modular/posix_socket_wrappers.cc
@@ -0,0 +1,37 @@
+// Copyright 2023 The Cobalt Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "starboard/shared/modular/posix_socket_wrappers.h"
+
+SbSocketError TranslateSocketErrnoToSbError(int error) {
+  switch (error) {
+    case 0:
+      return kSbSocketOk;
+    case EINPROGRESS:
+    case EAGAIN:
+#if EWOULDBLOCK != EAGAIN
+    case EWOULDBLOCK:
+#endif
+      return kSbSocketPending;
+    case ECONNRESET:
+    case ENETRESET:
+    case EPIPE:
+      return kSbSocketErrorConnectionReset;
+  }
+
+  SB_LOG(ERROR) << "Unknown posix socket error: " << error;
+
+  // Here's where we would be more nuanced if we need to be.
+  return kSbSocketErrorFailed;
+}
diff --git a/starboard/shared/modular/posix_socket_wrappers.h b/starboard/shared/modular/posix_socket_wrappers.h
new file mode 100644
index 000000000000..119c9a7e5c0d
--- /dev/null
+++ b/starboard/shared/modular/posix_socket_wrappers.h
@@ -0,0 +1,107 @@
+// Copyright 2023 The Cobalt Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef STARBOARD_SHARED_MODULAR_POSIX_SOCKET_WRAPPERS_H_
+#define STARBOARD_SHARED_MODULAR_POSIX_SOCKET_WRAPPERS_H_
+
+#include <errno.h>
+#include <netinet/in.h>
+#include <stdint.h>
+#include <sys/socket.h>
+
+#include "starboard/common/log.h"
+#include "starboard/configuration.h"
+#include "starboard/export.h"
+#include "starboard/socket.h"
+#include "starboard/types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct SbSocketWrapper;
+typedef struct SbSocketWrapper SbSocketWrapper;
+
+// A handle to a socket.
+typedef SbSocketWrapper* SbSocket;
+
+extern SbSocketError TranslateSocketErrnoToSbError(int error);
+
+// A helper class for converting back and forth from sockaddrs, ugh.
+class SockAddr {
+ public:
+  SockAddr() : length(sizeof(storage_)) {}
+  ~SockAddr() {}
+
+  // Initializes this SockAddr with the given SbSocketAddress, overwriting
+  // anything any address previously held.
+  bool FromSbSocketAddress(const SbSocketAddress* address);
+
+  // Initializes the given SbSocketAddress with this SockAddr, which must have
+  // been previously initialized.
+  bool ToSbSocketAddress(SbSocketAddress* out_address) const;
+
+  // Initializes this SockAddr with |sock_addr|, assuming it is appropriately
+  // sized for its type.
+  bool FromSockaddr(const struct sockaddr* sock_addr);
+
+  // The sockaddr family. We only support INET and INET6.
+  sa_family_t family() const { return sockaddr()->sa_family; }
+
+  struct sockaddr* sockaddr() {
+    return reinterpret_cast<struct sockaddr*>(&storage_);
+  }
+
+  const struct sockaddr* sockaddr() const {
+    return reinterpret_cast<const struct sockaddr*>(&storage_);
+  }
+
+  struct sockaddr_in* sockaddr_in() {
+    return reinterpret_cast<struct sockaddr_in*>(&storage_);
+  }
+
+  const struct sockaddr_in* sockaddr_in() const {
+    return reinterpret_cast<const struct sockaddr_in*>(&storage_);
+  }
+
+  struct sockaddr_in6* sockaddr_in6() {
+    return reinterpret_cast<struct sockaddr_in6*>(&storage_);
+  }
+
+  const struct sockaddr_in6* sockaddr_in6() const {
+    return reinterpret_cast<const struct sockaddr_in6*>(&storage_);
+  }
+
+  // Public on purpose, because it will be handy to be passed directly by
+  // reference into other functions.
+  socklen_t length;
+
+ private:
+  struct sockaddr_storage storage_;
+};
+
+#define HANDLE_EINTR_WRAPPER(x)                         \
+  ({                                                    \
+    decltype(x) __eintr_result__;                       \
+    do {                                                \
+      __eintr_result__ = (x);                           \
+    } while (__eintr_result__ == -1 && errno == EINTR); \
+    __eintr_result__;                                   \
+  })
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // STARBOARD_SHARED_MODULAR_POSIX_SOCKET_WRAPPERS_H_
diff --git a/starboard/shared/posix/socket_clear_last_error.cc b/starboard/shared/posix/socket_clear_last_error.cc
deleted file mode 100644
index 1610e80c7da1..000000000000
--- a/starboard/shared/posix/socket_clear_last_error.cc
+++ /dev/null
@@ -1,26 +0,0 @@
-// Copyright 2016 The Cobalt Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "starboard/common/socket.h"
-
-#include "starboard/shared/posix/socket_internal.h"
-
-bool SbSocketClearLastError(SbSocket socket) {
-  if (!SbSocketIsValid(socket)) {
-    return false;
-  }
-
-  socket->error = kSbSocketOk;
-  return true;
-}
diff --git a/starboard/shared/starboard/net_log.cc b/starboard/shared/starboard/net_log.cc
index 9ca41928fc36..c0c1331b9736 100644
--- a/starboard/shared/starboard/net_log.cc
+++ b/starboard/shared/starboard/net_log.cc
@@ -189,7 +189,7 @@ class BufferedSocketWriter {
                                     bytes_to_write, NULL);
 
         if (result < 0) {
-          SbSocketError err = SbSocketGetLastError(dest_socket);
+          SbSocketError err = dest_socket->error;
           SbSocketClearLastError(dest_socket);
           if (err == kSbSocketPending) {
             blocked_counts_.increment();
diff --git a/starboard/shared/stub/socket_clear_last_error.cc b/starboard/shared/stub/socket_clear_last_error.cc
deleted file mode 100644
index 03419f576ec4..000000000000
--- a/starboard/shared/stub/socket_clear_last_error.cc
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2016 The Cobalt Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "starboard/common/socket.h"
-
-bool SbSocketClearLastError(SbSocket socket) {
-  return false;
-}
diff --git a/starboard/shared/win32/socket_clear_last_error.cc b/starboard/shared/win32/socket_clear_last_error.cc
deleted file mode 100644
index 06f4a7deaed8..000000000000
--- a/starboard/shared/win32/socket_clear_last_error.cc
+++ /dev/null
@@ -1,26 +0,0 @@
-// Copyright 2017 The Cobalt Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "starboard/common/socket.h"
-
-#include "starboard/shared/win32/socket_internal.h"
-
-bool SbSocketClearLastError(SbSocket socket) {
-  if (!SbSocketIsValid(socket)) {
-    return false;
-  }
-
-  socket->error = kSbSocketOk;
-  return true;
-}
diff --git a/starboard/socket.h b/starboard/socket.h
index adcd32b3c072..f96d685e650d 100644
--- a/starboard/socket.h
+++ b/starboard/socket.h
@@ -41,12 +41,14 @@
 extern "C" {
 #endif
 
+#if SB_API_VERSION < 16
 // Private structure representing a socket, which may or may not be connected or
 // listening.
 typedef struct SbSocketPrivate SbSocketPrivate;
 
 // A handle to a socket.
 typedef SbSocketPrivate* SbSocket;
+#endif
 
 // Enumeration of all Starboard socket operation results. Despite the enum
 // name, note that the value actually describes the outcome of an operation,
@@ -126,6 +128,40 @@ typedef struct SbSocketResolution {
 // Well-defined value for an invalid socket handle.
 #define kSbSocketInvalid ((SbSocket)NULL)
 
+#if SB_API_VERSION >= 16
+#include "starboard/shared/modular/posix_socket_wrappers.h"
+#include "starboard/socket_waiter.h"
+// Private structure representing a socket, which may or may not be connected or
+// listening.
+struct SbSocketWrapper {
+  SbSocketWrapper(SbSocketAddressType address_type,
+                  SbSocketProtocol protocol,
+                  int fd)
+      : address_type(address_type),
+        protocol(protocol),
+        socket_fd(fd),
+        error(kSbSocketOk),
+        waiter(kSbSocketWaiterInvalid) {}
+  ~SbSocketWrapper() {}
+
+  // The address domain of this socket, IPv4 or IPv6.
+  SbSocketAddressType address_type;
+
+  // The protocol of this socket, UDP or TCP.
+  SbSocketProtocol protocol;
+
+  // The file descriptor for this socket.
+  int socket_fd;
+
+  // The last error that occurred on this socket, or kSbSocketOk.
+  SbSocketError error;
+
+  // The waiter this socket is registered with, or kSbSocketWaiterInvalid.
+  SbSocketWaiter waiter;
+};
+
+#endif
+
 // Returns whether the given socket handle is valid.
 static SB_C_INLINE bool SbSocketIsValid(SbSocket socket) {
   return socket != kSbSocketInvalid;
@@ -208,6 +244,7 @@ SB_EXPORT bool SbSocketIsConnected(SbSocket socket);
 // |socket|: The SbSocket to be checked.
 SB_EXPORT bool SbSocketIsConnectedAndIdle(SbSocket socket);
 
+#if SB_API_VERSION < 16
 // Returns the last error set on |socket|. If |socket| is not valid, this
 // function returns |kSbSocketErrorFailed|.
 //
@@ -217,6 +254,7 @@ SB_EXPORT SbSocketError SbSocketGetLastError(SbSocket socket);
 // Clears the last error set on |socket|. The return value indicates whether
 // the socket error was cleared.
 SB_EXPORT bool SbSocketClearLastError(SbSocket socket);
+#endif
 
 // Gets the address that this socket is bound to locally, if the socket is
 // connected. The return value indicates whether the address was retrieved
diff --git a/starboard/socket_waiter.h b/starboard/socket_waiter.h
index 18bbfbd9879c..00fe5679e116 100644
--- a/starboard/socket_waiter.h
+++ b/starboard/socket_waiter.h
@@ -39,6 +39,10 @@
 #include "starboard/time.h"
 #include "starboard/types.h"
 
+#if SB_API_VERSION >= 16
+#include "starboard/shared/modular/posix_socket_wrappers.h"
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/starboard/stub/BUILD.gn b/starboard/stub/BUILD.gn
index d85bef3de7be..99fcf5cde3cf 100644
--- a/starboard/stub/BUILD.gn
+++ b/starboard/stub/BUILD.gn
@@ -159,7 +159,6 @@ static_library("stub_sources") {
     "//starboard/shared/stub/player_write_samples.cc",
     "//starboard/shared/stub/socket_accept.cc",
     "//starboard/shared/stub/socket_bind.cc",
-    "//starboard/shared/stub/socket_clear_last_error.cc",
     "//starboard/shared/stub/socket_connect.cc",
     "//starboard/shared/stub/socket_create.cc",
     "//starboard/shared/stub/socket_destroy.cc",
diff --git a/starboard/win/shared/BUILD.gn b/starboard/win/shared/BUILD.gn
index 97376937da70..6129a34c2063 100644
--- a/starboard/win/shared/BUILD.gn
+++ b/starboard/win/shared/BUILD.gn
@@ -239,7 +239,6 @@ static_library("starboard_platform") {
     "//starboard/shared/win32/set_non_blocking_internal.h",
     "//starboard/shared/win32/socket_accept.cc",
     "//starboard/shared/win32/socket_bind.cc",
-    "//starboard/shared/win32/socket_clear_last_error.cc",
     "//starboard/shared/win32/socket_connect.cc",
     "//starboard/shared/win32/socket_create.cc",
     "//starboard/shared/win32/socket_destroy.cc",