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diff --git a/Source/Particles/ParticleCreation/DefaultInitialization.H b/Source/Particles/ParticleCreation/DefaultInitialization.H
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+#ifndef DEFAULTINITIALIZATION_H_
+#define DEFAULTINITIALIZATION_H_
+
+#include "AMReX_REAL.H"
+#include "AMReX_GpuContainers.H"
+
+#include <map>
+#include <string>
+
+/**
+ * \brief This set of initialization policies describes what happens
+ * when we need to create a new particle due to an elementary process.
+ * For example, when an ionization event creates an electron, these
+ * policies control the initial values of the electron's components.
+ * These can always be over-written later.
+ *
+ * The specific meanings are as follows:
+ *     Zero         - set the component to zero
+ *     One          - set the component to one
+ *     SignalingNan - set the component to a signalling nan. If you run
+ *                    with amrex.fpe_trap_invalid=1 AND built the code
+ *                    with gcc, this will throw an exception the first time
+ *                    it is used.
+ *     RandomTau    - a special flag for the "tau" component used by certain
+ *                    QED processes, which gets a random initial value.
+ *
+ */
+enum struct InitializationPolicy {Zero=0, One, SignalingNan, RandomTau};
+
+/**
+ * \brief This is a functor that implements the above InitializationPolicies
+ * in a switch statement. It is designed to be used in device code when
+ * running on GPUs.
+ */
+struct DefaultInitializer
+{
+    const InitializationPolicy* m_policies;
+
+    AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
+    amrex::Real operator() (int j) const noexcept
+    {
+        switch (m_policies[j]) {
+            case InitializationPolicy::Zero : return 0.0;
+            case InitializationPolicy::One  : return 1.0;
+            case InitializationPolicy::SignalingNan : {
+                return 1.0;
+            }
+            case InitializationPolicy::RandomTau : {
+                return 1.0;
+            }
+            default : {
+                amrex::Abort("Initialization Policy not recognized");
+                return 1.0;
+            }
+        }
+    }
+};
+
+/**
+ * \brief This map sets the initialization policy for each particle component
+ * used in WarpX.
+ */
+static std::map<std::string, InitializationPolicy> initialization_policies = {
+    {"w",     InitializationPolicy::Zero },
+    {"ux",    InitializationPolicy::Zero },
+    {"uy",    InitializationPolicy::Zero },
+    {"uz",    InitializationPolicy::Zero },
+    {"Ex",    InitializationPolicy::Zero },
+    {"Ey",    InitializationPolicy::Zero },
+    {"Ez",    InitializationPolicy::Zero },
+    {"Bx",    InitializationPolicy::Zero },
+    {"By",    InitializationPolicy::Zero },
+    {"Bz",    InitializationPolicy::Zero },
+    #ifdef WARPX_DIM_RZ
+    {"theta", InitializationPolicy::Zero},
+    #endif
+    {"tau", InitializationPolicy::RandomTau}
+};
+
+/**
+ * \brief This is a factory class that creates instances of "DefaultInitializer".
+ * Each particle type in WarpX has one of these associated with it. While
+ * "DefaultInitializer" is a lightweight class intended to be used on the device,
+ * this class is meant to be used on the host.
+ */
+class DefaultInitializerFactory
+{
+    amrex::Gpu::DeviceVector<InitializationPolicy> m_policies;
+    bool m_defined;
+
+public:
+
+    DefaultInitializerFactory () noexcept : m_defined(false) {};
+
+    void define (const std::map<std::string, int>& comps) noexcept
+    {
+        m_policies.resize(comps.size());
+        for (const auto& kv : comps)
+        {
+            m_policies[kv.second] = initialization_policies[kv.first];
+            m_defined = true;
+        }
+    }
+
+    DefaultInitializer getDefaultInitializer () const noexcept
+    {
+        AMREX_ASSERT(m_defined);
+        return DefaultInitializer{m_policies.dataPtr()};
+    }
+
+    bool isDefined () const noexcept { return m_defined; }
+};
+
+#endif