diff --git a/phosphor-regulators/src/device.cpp b/phosphor-regulators/src/device.cpp
index 3e7d5a4..dd662c9 100644
--- a/phosphor-regulators/src/device.cpp
+++ b/phosphor-regulators/src/device.cpp
@@ -16,6 +16,9 @@
 
 #include "device.hpp"
 
+#include "chassis.hpp"
+#include "system.hpp"
+
 namespace phosphor::power::regulators
 {
 
@@ -31,4 +34,19 @@
     }
 }
 
+void Device::configure(System& system, Chassis& chassis)
+{
+    // If configuration changes are defined for this device, apply them
+    if (configuration)
+    {
+        configuration->execute(system, chassis, *this);
+    }
+
+    // Configure rails
+    for (std::unique_ptr<Rail>& rail : rails)
+    {
+        rail->configure(system, chassis, *this);
+    }
+}
+
 } // namespace phosphor::power::regulators
diff --git a/phosphor-regulators/src/device.hpp b/phosphor-regulators/src/device.hpp
index 919899a..e9369fc 100644
--- a/phosphor-regulators/src/device.hpp
+++ b/phosphor-regulators/src/device.hpp
@@ -29,6 +29,10 @@
 namespace phosphor::power::regulators
 {
 
+// Forward declarations to avoid circular dependencies
+class Chassis;
+class System;
+
 /**
  * @class Device
  *
@@ -82,6 +86,22 @@
     void addToIDMap(IDMap& idMap);
 
     /**
+     * Configure this device.
+     *
+     * Applies the configuration changes that are defined for this device, if
+     * any.
+     *
+     * Also configures the voltage rails produced by this device, if any.
+     *
+     * This method should be called during the boot before regulators are
+     * enabled.
+     *
+     * @param system system that contains the chassis
+     * @param chassis chassis that contains this device
+     */
+    void configure(System& system, Chassis& chassis);
+
+    /**
      * Returns the configuration changes to apply to this device, if any.
      *
      * @return Pointer to Configuration object.  Will equal nullptr if no
diff --git a/phosphor-regulators/test/device_tests.cpp b/phosphor-regulators/test/device_tests.cpp
index c4875bf..1ce065c 100644
--- a/phosphor-regulators/test/device_tests.cpp
+++ b/phosphor-regulators/test/device_tests.cpp
@@ -14,13 +14,19 @@
  * limitations under the License.
  */
 #include "action.hpp"
+#include "chassis.hpp"
 #include "configuration.hpp"
 #include "device.hpp"
 #include "i2c_interface.hpp"
 #include "id_map.hpp"
+#include "journal.hpp"
 #include "mock_action.hpp"
+#include "mock_journal.hpp"
 #include "presence_detection.hpp"
 #include "rail.hpp"
+#include "rule.hpp"
+#include "sensor_monitoring.hpp"
+#include "system.hpp"
 #include "test_utils.hpp"
 
 #include <memory>
@@ -28,11 +34,14 @@
 #include <utility>
 #include <vector>
 
+#include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
 using namespace phosphor::power::regulators;
 using namespace phosphor::power::regulators::test_utils;
 
+using ::testing::Return;
+
 TEST(DeviceTests, Constructor)
 {
     // Test where only required parameters are specified
@@ -129,6 +138,120 @@
     EXPECT_THROW(idMap.getRail("vdd2"), std::invalid_argument);
 }
 
+TEST(DeviceTests, Configure)
+{
+    // Test where Configuration and Rails were not specified in constructor
+    {
+        // Create Device
+        std::unique_ptr<i2c::I2CInterface> i2cInterface = createI2CInterface();
+        std::unique_ptr<Device> device = std::make_unique<Device>(
+            "reg1", true, "/system/chassis/motherboard/reg1",
+            std::move(i2cInterface));
+        Device* devicePtr = device.get();
+
+        // Create Chassis that contains Device
+        std::vector<std::unique_ptr<Device>> devices{};
+        devices.emplace_back(std::move(device));
+        std::unique_ptr<Chassis> chassis =
+            std::make_unique<Chassis>(1, std::move(devices));
+        Chassis* chassisPtr = chassis.get();
+
+        // Create System that contains Chassis
+        std::vector<std::unique_ptr<Rule>> rules{};
+        std::vector<std::unique_ptr<Chassis>> chassisVec{};
+        chassisVec.emplace_back(std::move(chassis));
+        System system{std::move(rules), std::move(chassisVec)};
+
+        // Call configure().  Should do nothing.
+        journal::clear();
+        devicePtr->configure(system, *chassisPtr);
+        EXPECT_EQ(journal::getDebugMessages().size(), 0);
+        EXPECT_EQ(journal::getErrMessages().size(), 0);
+    }
+
+    // Test where Configuration and Rails were specified in constructor
+    {
+        std::vector<std::unique_ptr<Rail>> rails{};
+
+        // Create Rail vdd0
+        {
+            // Create Configuration for Rail
+            std::optional<double> volts{1.3};
+            std::unique_ptr<MockAction> action = std::make_unique<MockAction>();
+            EXPECT_CALL(*action, execute).Times(1).WillOnce(Return(true));
+            std::vector<std::unique_ptr<Action>> actions{};
+            actions.emplace_back(std::move(action));
+            std::unique_ptr<Configuration> configuration =
+                std::make_unique<Configuration>(volts, std::move(actions));
+
+            // Create Rail
+            std::unique_ptr<Rail> rail =
+                std::make_unique<Rail>("vdd0", std::move(configuration));
+            rails.emplace_back(std::move(rail));
+        }
+
+        // Create Rail vio0
+        {
+            // Create Configuration for Rail
+            std::optional<double> volts{3.2};
+            std::unique_ptr<MockAction> action = std::make_unique<MockAction>();
+            EXPECT_CALL(*action, execute).Times(1).WillOnce(Return(true));
+            std::vector<std::unique_ptr<Action>> actions{};
+            actions.emplace_back(std::move(action));
+            std::unique_ptr<Configuration> configuration =
+                std::make_unique<Configuration>(volts, std::move(actions));
+
+            // Create Rail
+            std::unique_ptr<Rail> rail =
+                std::make_unique<Rail>("vio0", std::move(configuration));
+            rails.emplace_back(std::move(rail));
+        }
+
+        // Create Configuration for Device
+        std::optional<double> volts{};
+        std::unique_ptr<MockAction> action = std::make_unique<MockAction>();
+        EXPECT_CALL(*action, execute).Times(1).WillOnce(Return(true));
+        std::vector<std::unique_ptr<Action>> actions{};
+        actions.emplace_back(std::move(action));
+        std::unique_ptr<Configuration> configuration =
+            std::make_unique<Configuration>(volts, std::move(actions));
+
+        // Create Device
+        std::unique_ptr<i2c::I2CInterface> i2cInterface = createI2CInterface();
+        std::unique_ptr<PresenceDetection> presenceDetection{};
+        std::unique_ptr<Device> device = std::make_unique<Device>(
+            "reg1", true, "/system/chassis/motherboard/reg1",
+            std::move(i2cInterface), std::move(presenceDetection),
+            std::move(configuration), std::move(rails));
+        Device* devicePtr = device.get();
+
+        // Create Chassis that contains Device
+        std::vector<std::unique_ptr<Device>> devices{};
+        devices.emplace_back(std::move(device));
+        std::unique_ptr<Chassis> chassis =
+            std::make_unique<Chassis>(1, std::move(devices));
+        Chassis* chassisPtr = chassis.get();
+
+        // Create System that contains Chassis
+        std::vector<std::unique_ptr<Rule>> rules{};
+        std::vector<std::unique_ptr<Chassis>> chassisVec{};
+        chassisVec.emplace_back(std::move(chassis));
+        System system{std::move(rules), std::move(chassisVec)};
+
+        // Call configure().  For the Device and both Rails, should execute the
+        // Configuration and log a debug message.
+        journal::clear();
+        devicePtr->configure(system, *chassisPtr);
+        std::vector<std::string> expectedDebugMessages{
+            "Configuring reg1",
+            "Configuring vdd0: volts=1.300000",
+            "Configuring vio0: volts=3.200000",
+        };
+        EXPECT_EQ(journal::getDebugMessages(), expectedDebugMessages);
+        EXPECT_EQ(journal::getErrMessages().size(), 0);
+    }
+}
+
 TEST(DeviceTests, GetConfiguration)
 {
     // Test where Configuration was not specified in constructor
diff --git a/phosphor-regulators/test/rail_tests.cpp b/phosphor-regulators/test/rail_tests.cpp
index 5781973..b0a3466 100644
--- a/phosphor-regulators/test/rail_tests.cpp
+++ b/phosphor-regulators/test/rail_tests.cpp
@@ -33,6 +33,7 @@
 #include <utility>
 #include <vector>
 
+#include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
 using namespace phosphor::power::regulators;