diff --git a/monitor/fan.cpp b/monitor/fan.cpp
index 2c29cb3..fc408de 100644
--- a/monitor/fan.cpp
+++ b/monitor/fan.cpp
@@ -21,10 +21,10 @@
 #include "types.hpp"
 #include "utility.hpp"
 
-#include <fmt/format.h>
-
 #include <phosphor-logging/log.hpp>
 
+#include <format>
+
 namespace phosphor
 {
 namespace fan
@@ -122,7 +122,7 @@
         if (!_present)
         {
             getLogger().log(
-                fmt::format("On startup, fan {} is missing", _name));
+                std::format("On startup, fan {} is missing", _name));
             if (_system.isPowerOn() && _fanMissingErrorTimer)
             {
                 _fanMissingErrorTimer->restartOnce(
@@ -161,7 +161,7 @@
 
     if (!_present)
     {
-        getLogger().log(fmt::format(
+        getLogger().log(std::format(
             "New fan {} interface added and fan is not present", _name));
         if (_system.isPowerOn() && _fanMissingErrorTimer)
         {
@@ -195,7 +195,7 @@
                 // The tach property still isn't on D-Bus. Ensure
                 // sensor is nonfunctional, but skip creating an
                 // error for it since it isn't a fan problem.
-                getLogger().log(fmt::format(
+                getLogger().log(std::format(
                     "Monitoring starting but {} sensor value not on D-Bus",
                     sensor->name()));
 
@@ -384,7 +384,7 @@
     // isn't on D-Bus as this isn't a fan hardware problem.
     sensor.setFunctional(!sensor.functional(), !sensor.hasOwner());
 
-    getLogger().log(fmt::format(
+    getLogger().log(std::format(
         "Setting tach sensor {} functional state to {}. "
         "[target = {}, actual = {}, allowed range = ({} - {}) "
         "owned = {}]",
@@ -402,7 +402,7 @@
         if (!_setFuncOnPresent && !_functional &&
             !(numNonFuncSensors >= _numSensorFailsForNonFunc))
         {
-            getLogger().log(fmt::format("Setting fan {} to functional, number "
+            getLogger().log(std::format("Setting fan {} to functional, number "
                                         "of nonfunctional sensors = {}",
                                         _name, numNonFuncSensors));
             updateInventory(true);
@@ -413,7 +413,7 @@
         // the fan to nonfunctional.
         if (_functional && (numNonFuncSensors >= _numSensorFailsForNonFunc))
         {
-            getLogger().log(fmt::format("Setting fan {} to nonfunctional, "
+            getLogger().log(std::format("Setting fan {} to nonfunctional, "
                                         "number of nonfunctional sensors = {}",
                                         _name, numNonFuncSensors));
             updateInventory(false);
@@ -451,7 +451,7 @@
         dbusError = true;
 
         getLogger().log(
-            fmt::format("D-Bus Exception reading/updating inventory : {}",
+            std::format("D-Bus Exception reading/updating inventory : {}",
                         e.what()),
             Logger::error);
     }
@@ -475,7 +475,7 @@
         _present = std::get<bool>(presentProp->second);
 
         getLogger().log(
-            fmt::format("Fan {} presence state change to {}", _name, _present));
+            std::format("Fan {} presence state change to {}", _name, _present));
 
         if (_present && _setFuncOnPresent)
         {
@@ -550,7 +550,7 @@
                 // Properties still aren't on D-Bus.  Let startMonitor()
                 // deal with it, or maybe System::powerStateChanged() if
                 // there aren't any sensors at all on D-Bus.
-                getLogger().log(fmt::format(
+                getLogger().log(std::format(
                     "At power on, tach sensor {} value not on D-Bus",
                     sensor->name()));
             }
@@ -572,7 +572,7 @@
         else
         {
             getLogger().log(
-                fmt::format("At power on, fan {} is missing", _name));
+                std::format("At power on, fan {} is missing", _name));
 
             if (_fanMissingErrorTimer)
             {
diff --git a/monitor/fan_error.cpp b/monitor/fan_error.cpp
index f0a6f32..396b731 100644
--- a/monitor/fan_error.cpp
+++ b/monitor/fan_error.cpp
@@ -73,7 +73,7 @@
     if (_fd() == -1)
     {
         auto e = errno;
-        getLogger().log(fmt::format("Could not open FFDC file {}. errno {}",
+        getLogger().log(std::format("Could not open FFDC file {}. errno {}",
                                     _name.string(), e));
     }
 }
@@ -120,7 +120,7 @@
     catch (const DBusError& e)
     {
         getLogger().log(
-            fmt::format("Call to create a {} error for fan {} failed: {}",
+            std::format("Call to create a {} error for fan {} failed: {}",
                         _errorName, _fanName, e.what()),
             Logger::error);
     }
@@ -164,7 +164,7 @@
     catch (const std::exception& e)
     {
         log<level::ERR>(
-            fmt::format("Could not save log contents in FFDC. Error msg: {}",
+            std::format("Could not save log contents in FFDC. Error msg: {}",
                         e.what())
                 .c_str());
     }
@@ -194,7 +194,7 @@
     else
     {
         auto e = errno;
-        getLogger().log(fmt::format("Failed called to mkstemp, errno = {}", e),
+        getLogger().log(std::format("Failed called to mkstemp, errno = {}", e),
                         Logger::error);
     }
     return nullptr;
diff --git a/monitor/json_parser.cpp b/monitor/json_parser.cpp
index 4d06540..b5b7291 100644
--- a/monitor/json_parser.cpp
+++ b/monitor/json_parser.cpp
@@ -23,12 +23,11 @@
 #include "tach_sensor.hpp"
 #include "types.hpp"
 
-#include <fmt/format.h>
-
 #include <nlohmann/json.hpp>
 #include <phosphor-logging/log.hpp>
 
 #include <algorithm>
+#include <format>
 #include <map>
 #include <memory>
 #include <optional>
@@ -213,7 +212,7 @@
         auto deviation = fan["deviation"].get<size_t>();
         if (100 < deviation)
         {
-            auto msg = fmt::format(
+            auto msg = std::format(
                 "Invalid deviation of {} found, must be between 0 and 100",
                 deviation);
 
@@ -230,7 +229,7 @@
             if (100 < upperDeviation)
             {
                 auto msg =
-                    fmt::format("Invalid upper_deviation of {} found, must "
+                    std::format("Invalid upper_deviation of {} found, must "
                                 "be between 0 and 100",
                                 upperDeviation);
 
@@ -409,7 +408,7 @@
         }
         else if (state != "runtime")
         {
-            auto msg = fmt::format("Invalid power off state entry {}", state);
+            auto msg = std::format("Invalid power off state entry {}", state);
             log<level::ERR>(msg.c_str());
             throw std::runtime_error(msg.c_str());
         }
@@ -449,7 +448,7 @@
     else
     {
         auto msg =
-            fmt::format("Invalid power off cause {} in power off config JSON",
+            std::format("Invalid power off cause {} in power off config JSON",
                         powerOffCause);
         log<level::ERR>(msg.c_str());
         throw std::runtime_error(msg.c_str());
@@ -509,7 +508,7 @@
     }
     else
     {
-        auto msg = fmt::format("Invalid 'type' entry {} in power off config",
+        auto msg = std::format("Invalid 'type' entry {} in power off config",
                                type);
         log<level::ERR>(msg.c_str());
         throw std::runtime_error(msg.c_str());
diff --git a/monitor/power_interface.cpp b/monitor/power_interface.cpp
index f6589b8..dbfcfda 100644
--- a/monitor/power_interface.cpp
+++ b/monitor/power_interface.cpp
@@ -49,7 +49,7 @@
     catch (const std::exception& e)
     {
         getLogger().log(
-            fmt::format("Caught exception while creating BMC dump: {}",
+            std::format("Caught exception while creating BMC dump: {}",
                         e.what()),
             Logger::error);
     }
diff --git a/monitor/power_off_action.hpp b/monitor/power_off_action.hpp
index c833038..6d7580b 100644
--- a/monitor/power_off_action.hpp
+++ b/monitor/power_off_action.hpp
@@ -4,13 +4,12 @@
 #include "power_interface.hpp"
 #include "sdbusplus.hpp"
 
-#include <fmt/format.h>
-
 #include <sdeventplus/clock.hpp>
 #include <sdeventplus/event.hpp>
 #include <sdeventplus/utility/timer.hpp>
 
 #include <chrono>
+#include <format>
 
 namespace phosphor::fan::monitor
 {
@@ -113,7 +112,7 @@
         catch (const std::exception& e)
         {
             getLogger().log(
-                fmt::format("Caught exception while creating BMC dump: {}",
+                std::format("Caught exception while creating BMC dump: {}",
                             e.what()),
                 Logger::error);
         }
@@ -215,7 +214,7 @@
         }
 
         getLogger().log(
-            fmt::format("Action '{}' executing hard power off", name()));
+            std::format("Action '{}' executing hard power off", name()));
         _powerIface->hardPowerOff();
 
         createBmcDump();
@@ -307,7 +306,7 @@
         }
 
         getLogger().log(
-            fmt::format("Action '{}' executing soft power off", name()));
+            std::format("Action '{}' executing soft power off", name()));
         _powerIface->softPowerOff();
 
         createBmcDump();
@@ -380,7 +379,7 @@
     void start() override
     {
         getLogger().log(
-            fmt::format("Action {}: Starting service mode timer", name()));
+            std::format("Action {}: Starting service mode timer", name()));
 
         _serviceModeTimer.restartOnce(_serviceModeDelay);
     }
@@ -393,7 +392,7 @@
      */
     void serviceModeTimerExpired()
     {
-        getLogger().log(fmt::format(
+        getLogger().log(std::format(
             "Action {}: Service mode timer expired, starting meltdown timer",
             name()));
 
@@ -408,7 +407,7 @@
      */
     void meltdownTimerExpired()
     {
-        getLogger().log(fmt::format(
+        getLogger().log(std::format(
             "Action {}: Meltdown timer expired, executing hard power off",
             name()));
 
diff --git a/monitor/power_off_rule.hpp b/monitor/power_off_rule.hpp
index 3172bd5..ad17870 100644
--- a/monitor/power_off_rule.hpp
+++ b/monitor/power_off_rule.hpp
@@ -84,7 +84,7 @@
         {
             // Start the action
             getLogger().log(
-                fmt::format("Starting shutdown action '{}' due to cause '{}'",
+                std::format("Starting shutdown action '{}' due to cause '{}'",
                             _action->name(), _cause->name()));
 
             _active = true;
@@ -95,13 +95,13 @@
             // Attempt to cancel the action, but don't force it
             if (_action->cancel(false))
             {
-                getLogger().log(fmt::format("Stopped shutdown action '{}'",
+                getLogger().log(std::format("Stopped shutdown action '{}'",
                                             _action->name()));
                 _active = false;
             }
             else
             {
-                getLogger().log(fmt::format(
+                getLogger().log(std::format(
                     "Could not stop shutdown action '{}'", _action->name()));
             }
         }
diff --git a/monitor/system.cpp b/monitor/system.cpp
index 4a33bb5..bb2e95e 100644
--- a/monitor/system.cpp
+++ b/monitor/system.cpp
@@ -167,7 +167,7 @@
                 if (serviceObjects.end() == itServ || itServ->second.empty())
                 {
                     getLogger().log(
-                        fmt::format("Fan sensor entry {} not found in D-Bus",
+                        std::format("Fan sensor entry {} not found in D-Bus",
                                     sensor->name()),
                         Logger::error);
                     continue;
@@ -304,7 +304,7 @@
     bool hasOwner = !newOwner.empty() && oldOwner.empty();
 
     std::string stateStr(hasOwner ? "online" : "offline");
-    getLogger().log(fmt::format("Changing sensors for service {} to {}",
+    getLogger().log(std::format("Changing sensors for service {} to {}",
                                 serviceName, stateStr),
                     Logger::info);
 
@@ -429,7 +429,7 @@
     std::string fanPath{util::INVENTORY_PATH + fan.getName()};
 
     getLogger().log(
-        fmt::format("Creating event log for faulted fan {} sensor {}", fanPath,
+        std::format("Creating event log for faulted fan {} sensor {}", fanPath,
                     sensor.name()),
         Logger::error);
 
@@ -473,7 +473,7 @@
     std::string fanPath{util::INVENTORY_PATH + fan.getName()};
 
     getLogger().log(
-        fmt::format("Creating event log for missing fan {}", fanPath),
+        std::format("Creating event log for missing fan {}", fanPath),
         Logger::error);
 
     auto error = std::make_unique<FanError>(
@@ -568,7 +568,7 @@
     catch (const std::exception& e)
     {
         getLogger().log(
-            fmt::format("Caught exception while creating BMC dump: {}",
+            std::format("Caught exception while creating BMC dump: {}",
                         e.what()),
             Logger::error);
     }
diff --git a/monitor/tach_sensor.cpp b/monitor/tach_sensor.cpp
index 3030d5c..1d92231 100644
--- a/monitor/tach_sensor.cpp
+++ b/monitor/tach_sensor.cpp
@@ -19,12 +19,11 @@
 #include "sdbusplus.hpp"
 #include "utility.hpp"
 
-#include <fmt/format.h>
-
 #include <phosphor-logging/elog.hpp>
 #include <phosphor-logging/log.hpp>
 
 #include <filesystem>
+#include <format>
 #include <functional>
 #include <optional>
 #include <utility>
@@ -321,7 +320,7 @@
     if (!timerRunning() || mode != _timerMode)
     {
         log<level::DEBUG>(
-            fmt::format("Start timer({}) on tach sensor {}. [delay = {}s]",
+            std::format("Start timer({}) on tach sensor {}. [delay = {}s]",
                         static_cast<int>(mode), _name,
                         duration_cast<seconds>(getDelay(mode)).count())
                 .c_str());
@@ -357,7 +356,7 @@
         {
             ++_counter;
             log<level::DEBUG>(
-                fmt::format(
+                std::format(
                     "Incremented error counter on {} to {} (threshold {})",
                     _name, _counter, _threshold)
                     .c_str());
@@ -369,7 +368,7 @@
         {
             --_counter;
             log<level::DEBUG>(
-                fmt::format(
+                std::format(
                     "Decremented error counter on {} to {} (threshold {})",
                     _name, _counter, _threshold)
                     .c_str());
@@ -382,7 +381,7 @@
     if (_countTimer)
     {
         log<level::DEBUG>(
-            fmt::format("Starting count timer on sensor {}", _name).c_str());
+            std::format("Starting count timer on sensor {}", _name).c_str());
         _countTimer->restart(std::chrono::seconds(_countInterval));
     }
 }
@@ -392,7 +391,7 @@
     if (_countTimer && _countTimer->isEnabled())
     {
         log<level::DEBUG>(
-            fmt::format("Stopping count timer on tach sensor {}.", _name)
+            std::format("Stopping count timer on tach sensor {}.", _name)
                 .c_str());
         _countTimer->setEnabled(false);
     }
diff --git a/monitor/tach_sensor.hpp b/monitor/tach_sensor.hpp
index b4dc5b5..1468ab1 100644
--- a/monitor/tach_sensor.hpp
+++ b/monitor/tach_sensor.hpp
@@ -1,7 +1,5 @@
 #pragma once
 
-#include <fmt/format.h>
-
 #include <phosphor-logging/log.hpp>
 #include <sdbusplus/bus.hpp>
 #include <sdbusplus/bus/match.hpp>
@@ -11,6 +9,7 @@
 
 #include <chrono>
 #include <deque>
+#include <format>
 #include <optional>
 #include <utility>
 
@@ -287,7 +286,7 @@
     inline void stopTimer()
     {
         phosphor::logging::log<phosphor::logging::level::DEBUG>(
-            fmt::format("Stop running timer on tach sensor {}.", _name)
+            std::format("Stop running timer on tach sensor {}.", _name)
                 .c_str());
         _timer.setEnabled(false);
     }