diff --git a/ompi/mca/mtl/ofi/Makefile.am b/ompi/mca/mtl/ofi/Makefile.am
index 5842abd3018..7baad1b211f 100644
--- a/ompi/mca/mtl/ofi/Makefile.am
+++ b/ompi/mca/mtl/ofi/Makefile.am
@@ -9,7 +9,7 @@
 #                         and Technology (RIST).  All rights reserved.
 # Copyright (c) 2020      Triad National Security, LLC. All rights
 #                         reserved.
-# Copyright (c) 2022      Amazon.com, Inc. or its affiliates.  All Rights reserved.
+# Copyright (c) 2022-2025 Amazon.com, Inc. or its affiliates.  All Rights reserved.
 # Copyright (c) 2025      Jeffrey M. Squyres.  All rights reserved.
 # $COPYRIGHT$
 #
@@ -48,6 +48,7 @@ mtl_ofi_sources = \
     mtl_ofi_component.c \
     mtl_ofi_endpoint.h \
     mtl_ofi_endpoint.c \
+    mtl_ofi_mr.c \
     mtl_ofi_request.h \
     mtl_ofi_types.h \
     mtl_ofi_opt.h \
diff --git a/ompi/mca/mtl/ofi/mtl_ofi.h b/ompi/mca/mtl/ofi/mtl_ofi.h
index aae756b0518..323477d74f4 100644
--- a/ompi/mca/mtl/ofi/mtl_ofi.h
+++ b/ompi/mca/mtl/ofi/mtl_ofi.h
@@ -4,8 +4,7 @@
  *                         reserved.
  * Copyright (c) 2019-2024 Triad National Security, LLC. All rights
  *                         reserved.
- * Copyright (c) 2018-2023 Amazon.com, Inc. or its affiliates.  All Rights reserved.
- *                         reserved.
+ * Copyright (c) 2018-2025 Amazon.com, Inc. or its affiliates.  All Rights reserved.
  * Copyright (c) 2021      Cisco Systems, Inc.  All rights reserved
  * Copyright (c) 2021      The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
@@ -73,6 +72,8 @@ extern int ompi_mtl_ofi_del_comm(struct mca_mtl_base_module_t *mtl,
 
 int ompi_mtl_ofi_progress_no_inline(void);
 
+int ompi_mtl_ofi_rcache_init(void);
+
 #if OPAL_HAVE_THREAD_LOCAL
 extern opal_thread_local int ompi_mtl_ofi_per_thread_ctx;
 #endif
@@ -291,78 +292,37 @@ ompi_mtl_ofi_set_mr_null(ompi_mtl_ofi_request_t *ofi_req) {
 static
 int ompi_mtl_ofi_register_buffer(struct opal_convertor_t *convertor,
                                  ompi_mtl_ofi_request_t *ofi_req,
-                                 void* buffer) {
+                                 void* buffer)
+{
+    int ret;
+    uint32_t cache_flags = 0;
+
     ofi_req->mr = NULL;
     if (ofi_req->length <= 0 || NULL == buffer) {
         return OMPI_SUCCESS;
     }
 
-#if OPAL_OFI_HAVE_FI_MR_IFACE
-
-    if ((convertor->flags & CONVERTOR_ACCELERATOR) && ompi_mtl_ofi.hmem_needs_reg) {
-        /* Register buffer */
-        int ret;
-        struct fi_mr_attr attr = {0};
-        struct iovec iov = {0};
-
-        iov.iov_base = buffer;
-        iov.iov_len = ofi_req->length;
-        attr.mr_iov = &iov;
-        attr.iov_count = 1;
-        attr.access = FI_SEND | FI_RECV;
-        attr.offset = 0;
-        attr.context = NULL;
-        if (false == ompi_mtl_base_selected_component->accelerator_support) {
-            goto reg;
-        } else if (0 == strcmp(opal_accelerator_base_selected_component.base_version.mca_component_name, "cuda")) {
-            attr.iface = FI_HMEM_CUDA;
-            opal_accelerator.get_device(&attr.device.cuda);
-#if OPAL_OFI_HAVE_FI_HMEM_ROCR
-        } else if (0 == strcmp(opal_accelerator_base_selected_component.base_version.mca_component_name, "rocm")) {
-            attr.iface = FI_HMEM_ROCR;
-            opal_accelerator.get_device(&attr.device.cuda);
-#endif
-#if OPAL_OFI_HAVE_FI_HMEM_ZE
-        } else if (0 == strcmp(opal_accelerator_base_selected_component.base_version.mca_component_name, "ze")) {
-            attr.iface = FI_HMEM_ZE;
-            opal_accelerator.get_device(&attr.device.ze);
-#endif
-        } else {
-            return OPAL_ERROR;
-        }
-reg:
-        ret = fi_mr_regattr(ompi_mtl_ofi.domain, &attr, 0, &ofi_req->mr);
-
-        if (ret) {
-            opal_show_help("help-mtl-ofi.txt", "Buffer Memory Registration Failed", true,
-                           opal_accelerator_base_selected_component.base_version.mca_component_name,
-                           buffer, ofi_req->length,
-                           fi_strerror(-ret), ret);
-            ofi_req->mr = NULL;
-            return OMPI_ERROR;
-        }
+    if (! ((convertor->flags & CONVERTOR_ACCELERATOR) && ompi_mtl_ofi.hmem_needs_reg)) {
+        return OMPI_SUCCESS;
     }
 
-#endif
-
-    return OMPI_SUCCESS;
+    /* note - the cache access flags are a little broken, because rcache doesn't
+     * understand send/recv requirements.  Since this rcache is only used in the
+     * MTL, that isn't a problem and we fix it in the underlying register call.
+     */
+    ret = ompi_mtl_ofi.rcache->rcache_register(ompi_mtl_ofi.rcache, buffer, ofi_req->length,
+                                               cache_flags, MCA_RCACHE_ACCESS_ANY,
+                                               (mca_rcache_base_registration_t **) &ofi_req->mr);
+    return ret;
 }
 
 /** Deregister buffer */
 __opal_attribute_always_inline__ static inline int
 ompi_mtl_ofi_deregister_buffer(ompi_mtl_ofi_request_t *ofi_req) {
     if (ofi_req->mr) {
-        int ret;
-        ret = fi_close(&ofi_req->mr->fid);
-        if (ret) {
-            opal_show_help("help-mtl-ofi.txt", "OFI call fail", true,
-                           "fi_close",
-                           ompi_process_info.nodename, __FILE__, __LINE__,
-                           fi_strerror(-ret), ofi_req->mr->fid);
-            return OMPI_ERROR;
-        }
-        ofi_req->mr = NULL;
+        (void)ompi_mtl_ofi.rcache->rcache_deregister(ompi_mtl_ofi.rcache, &ofi_req->mr->base);
     }
+
     return OMPI_SUCCESS;
 }
 
diff --git a/ompi/mca/mtl/ofi/mtl_ofi_component.c b/ompi/mca/mtl/ofi/mtl_ofi_component.c
index 256dd483fc0..049ff4cf8c8 100644
--- a/ompi/mca/mtl/ofi/mtl_ofi_component.c
+++ b/ompi/mca/mtl/ofi/mtl_ofi_component.c
@@ -5,7 +5,7 @@
  * Copyright (c) 2014-2021 Cisco Systems, Inc.  All rights reserved
  * Copyright (c) 2015-2016 Los Alamos National Security, LLC.  All rights
  *                         reserved.
- * Copyright (c) 2018-2022 Amazon.com, Inc. or its affiliates.  All Rights reserved.
+ * Copyright (c) 2018-2025 Amazon.com, Inc. or its affiliates.  All Rights reserved.
  * Copyright (c) 2020-2023 Triad National Security, LLC. All rights
  *                         reserved.
  * $COPYRIGHT$
@@ -823,20 +823,17 @@ ompi_mtl_ofi_component_init(bool enable_progress_threads,
         }
     } else {
         *accelerator_support = true;
-        ompi_mtl_ofi.hmem_needs_reg = true;
-        /*
-         * Workaround for the fact that the CXI provider actually doesn't need for accelerator memory to be registered
-         * for local buffers, but if one does do so using fi_mr_regattr, one actually needs to manage the
-         * requested_key field in the fi_mr_attr attr argument, and the OFI MTL doesn't track which requested_keys
-         * have already been registered. So just set a flag to disable local registration.  Note the OFI BTL doesn't
-         * have a problem here since it uses fi_mr_regattr only within the context of an rcache, and manages the
-         * requested_key field in this way.
-         */
-         if ((NULL != strstr(prov->fabric_attr->prov_name, "cxi")) ||
-             (NULL != strstr(prov->fabric_attr->prov_name, "CXI")) ) {
-             ompi_mtl_ofi.hmem_needs_reg = false;
-         }
 
+        /* Only explicitly register domain buffers if the provider requires it.
+           For example, CXI does not require it but EFA does require it. */
+        if ((prov->domain_attr->mr_mode & FI_MR_HMEM) != 0) {
+            ompi_mtl_ofi.hmem_needs_reg = true;
+            opal_output_verbose(50, opal_common_ofi.output,
+                                "Support for device buffers enabled with explicit registration");
+        } else {
+            opal_output_verbose(50, opal_common_ofi.output,
+                                "Support for device buffers enabled with implicit registration");
+        }
     }
 #else
     opal_output_verbose(50, opal_common_ofi.output,
@@ -844,6 +841,10 @@ ompi_mtl_ofi_component_init(bool enable_progress_threads,
                         __FILE__, __LINE__);
 #endif
 
+    if (ompi_mtl_ofi.hmem_needs_reg) {
+        ompi_mtl_ofi_rcache_init();
+    }
+
     /**
      * Select the format of the OFI tag
      */
@@ -1177,6 +1178,11 @@ ompi_mtl_ofi_finalize(struct mca_mtl_base_module_t *mtl)
 {
     ssize_t ret;
 
+    if (NULL != ompi_mtl_ofi.rcache) {
+        mca_rcache_base_module_destroy(ompi_mtl_ofi.rcache);
+        ompi_mtl_ofi.rcache = NULL;
+    }
+
     opal_progress_unregister(ompi_mtl_ofi_progress_no_inline);
 
     /* Close all the OFI objects */
diff --git a/ompi/mca/mtl/ofi/mtl_ofi_mr.c b/ompi/mca/mtl/ofi/mtl_ofi_mr.c
new file mode 100644
index 00000000000..2f39a98ba23
--- /dev/null
+++ b/ompi/mca/mtl/ofi/mtl_ofi_mr.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2025      Amazon.com, Inc. or its affiliates.  All Rights reserved.
+ *
+ * $COPYRIGHT$
+ *
+ * Additional copyrights may follow
+ *
+ * $HEADER$
+ */
+
+#include "opal_config.h"
+
+#include "mtl_ofi.h"
+
+static int
+ompi_mtl_ofi_reg_mem(void *reg_data, void *base, size_t size,
+                     mca_rcache_base_registration_t *reg)
+{
+    int ret;
+    struct fi_mr_attr attr = {0};
+    struct iovec iov = {0};
+    ompi_mtl_ofi_reg_t *mtl_reg = (ompi_mtl_ofi_reg_t *)reg;
+    int dev_id;
+    uint64_t flags;
+
+    iov.iov_base = base;
+    iov.iov_len = size;
+    attr.mr_iov = &iov;
+    attr.iov_count = 1;
+    attr.access = FI_SEND | FI_RECV;
+    attr.offset = 0;
+    attr.context = NULL;
+
+#if  OPAL_OFI_HAVE_FI_MR_IFACE
+    if (OPAL_LIKELY(NULL != base)) {
+        ret = opal_accelerator.check_addr(base, &dev_id, &flags);
+        if (ret < 0) {
+            return ret;
+        } else if (ret > 0 ) {
+            if (0 == strcmp(opal_accelerator_base_selected_component.base_version.mca_component_name, "cuda")) {
+                attr.iface = FI_HMEM_CUDA;
+                opal_accelerator.get_device(&attr.device.cuda);
+#if OPAL_OFI_HAVE_FI_HMEM_ROCR
+	    } else if (0 == strcmp(opal_accelerator_base_selected_component.base_version.mca_component_name, "rocm")) {
+                attr.iface = FI_HMEM_ROCR;
+                opal_accelerator.get_device(&attr.device.cuda);
+#endif
+#if OPAL_OFI_HAVE_FI_HMEM_ZE
+            } else if (0 == strcmp(opal_accelerator_base_selected_component.base_version.mca_component_name, "ze")) {
+                attr.iface = FI_HMEM_ZE;
+                opal_accelerator.get_device(&attr.device.ze);
+#endif
+            } else {
+                return OPAL_ERROR;
+            }
+        }
+    }
+#endif
+
+    ret = fi_mr_regattr(ompi_mtl_ofi.domain, &attr, 0, &mtl_reg->ofi_mr);
+    if (0 != ret) {
+        opal_show_help("help-mtl-ofi.txt", "Buffer Memory Registration Failed", true,
+                       opal_accelerator_base_selected_component.base_version.mca_component_name,
+                       base, size, fi_strerror(-ret), ret);
+        mtl_reg->ofi_mr = NULL;
+        return OPAL_ERR_OUT_OF_RESOURCE;
+    }
+
+    mtl_reg->mem_desc = fi_mr_desc(mtl_reg->ofi_mr);
+
+    return OPAL_SUCCESS;
+}
+
+
+static int
+ompi_mtl_ofi_dereg_mem(void *reg_data, mca_rcache_base_registration_t *reg)
+{
+    ompi_mtl_ofi_reg_t *mtl_reg = (ompi_mtl_ofi_reg_t *)reg;
+    int ret;
+
+    if (mtl_reg->ofi_mr != NULL) {
+        ret = fi_close(&mtl_reg->ofi_mr->fid);
+        if (0 != ret) {
+            opal_output_verbose(1, opal_common_ofi.output,
+                                "%s: error unpinning memory mr=%p: %s",
+                                __func__, (void *)mtl_reg->ofi_mr,
+                                fi_strerror(-ret));
+            return OPAL_ERROR;
+        }
+    }
+
+    return OPAL_SUCCESS;
+}
+
+
+int
+ompi_mtl_ofi_rcache_init(void)
+{
+    mca_rcache_base_resources_t rcache_resources;
+    char *tmp;
+
+    if (NULL != ompi_mtl_ofi.rcache) {
+        return OMPI_SUCCESS;
+    }
+
+    tmp = strdup("mtl-ofi");
+    rcache_resources.cache_name = tmp;
+    rcache_resources.reg_data = NULL;
+    rcache_resources.sizeof_reg = sizeof(ompi_mtl_ofi_reg_t);
+    rcache_resources.register_mem = ompi_mtl_ofi_reg_mem;
+    rcache_resources.deregister_mem = ompi_mtl_ofi_dereg_mem;
+
+    ompi_mtl_ofi.rcache = mca_rcache_base_module_create("grdma", &ompi_mtl_ofi, &rcache_resources);
+    free(tmp);
+
+    if (NULL == ompi_mtl_ofi.rcache) {
+        /* something when horribly wrong */
+        opal_output_verbose(1, opal_common_ofi.output,
+                            "creating rcache failed");
+        return OMPI_ERROR;
+    }
+
+    return OMPI_SUCCESS;
+}
diff --git a/ompi/mca/mtl/ofi/mtl_ofi_request.h b/ompi/mca/mtl/ofi/mtl_ofi_request.h
index cb746f341db..74355f7bca0 100644
--- a/ompi/mca/mtl/ofi/mtl_ofi_request.h
+++ b/ompi/mca/mtl/ofi/mtl_ofi_request.h
@@ -2,6 +2,7 @@
  * Copyright (c) 2013-2016 Intel, Inc. All rights reserved
  * Copyright (c) 2017      Los Alamos National Security, LLC. All rights
  *                         reserved.
+ * Copyright (c) 2025      Amazon.com, Inc. or its affiliates.  All Rights reserved.
  *
  * $COPYRIGHT$
  *
@@ -25,6 +26,7 @@ typedef enum {
     OMPI_MTL_OFI_PROBE
 } ompi_mtl_ofi_request_type_t;
 
+struct ompi_mtl_ofi_reg_t;
 struct ompi_mtl_ofi_request_t;
 
 struct ompi_mtl_ofi_request_t {
@@ -89,8 +91,9 @@ struct ompi_mtl_ofi_request_t {
     struct mca_mtl_request_t *mrecv_req;
 
     /** Stores reference to memory region from registration */
-    /*  Set to NULL if memory not registered or if non accelerator buffer */
-    struct fid_mr *mr;
+
+    /*  Set to NULL if memory not registered */
+    struct ompi_mtl_ofi_reg_t *mr;
 };
 typedef struct ompi_mtl_ofi_request_t ompi_mtl_ofi_request_t;
 
diff --git a/ompi/mca/mtl/ofi/mtl_ofi_types.h b/ompi/mca/mtl/ofi/mtl_ofi_types.h
index a925f0ec28e..b89cc2c274e 100644
--- a/ompi/mca/mtl/ofi/mtl_ofi_types.h
+++ b/ompi/mca/mtl/ofi/mtl_ofi_types.h
@@ -4,6 +4,7 @@
  * Copyright (c) 2015 Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2022-2023 Triad National Security, LLC. All rights
  *                         reserved.
+ * Copyright (c) 2025      Amazon.com, Inc. or its affiliates.  All Rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -16,6 +17,9 @@
 
 #include "mtl_ofi.h"
 
+#include "opal/mca/rcache/base/base.h"
+
+
 BEGIN_C_DECLS
 
 /**
@@ -102,6 +106,8 @@ typedef struct mca_mtl_ofi_module_t {
     bool has_posted_initial_buffer;
     bool hmem_needs_reg;
 
+    /** registration cache */
+    mca_rcache_base_module_t *rcache;
 } mca_mtl_ofi_module_t;
 
 extern mca_mtl_ofi_module_t ompi_mtl_ofi;
@@ -116,6 +122,14 @@ typedef enum {
     OFI_SCALABLE_EP,
 } mca_mtl_ofi_ep_type;
 
+struct ompi_mtl_ofi_reg_t {
+    mca_rcache_base_registration_t base;
+    struct fid_mr *ofi_mr;
+    void *mem_desc;
+};
+typedef struct ompi_mtl_ofi_reg_t ompi_mtl_ofi_reg_t;
+
+
 /*
  * Define upper limit for number of events read from a CQ.
  * Setting this to 100 as this was deemed optimal from empirical data.
diff --git a/opal/mca/btl/ofi/btl_ofi.h b/opal/mca/btl/ofi/btl_ofi.h
index 0019065ecfe..e12d490b390 100644
--- a/opal/mca/btl/ofi/btl_ofi.h
+++ b/opal/mca/btl/ofi/btl_ofi.h
@@ -13,8 +13,7 @@
  * Copyright (c) 2015-2018 Los Alamos National Security, LLC. All rights
  *                         reserved.
  * Copyright (c) 2018-2019 Intel, Inc.  All rights reserved.
- * Copyright (c) 2020      Amazon.com, Inc. or its affiliates.
- *                         All Rights reserved.
+ * Copyright (c) 2020-2025 Amazon.com, Inc. or its affiliates.  All Rights reserved.
  * Copyright (c) 2022      Triad National Security, LLC. All rights
  *                         reserved.
  * $COPYRIGHT$
@@ -140,9 +139,6 @@ struct mca_btl_ofi_module_t {
 
     /** registration cache */
     mca_rcache_base_module_t *rcache;
-    /* If the underlying OFI provider has its own cache, we want to bypass
-     * rcache registration */
-    bool bypass_cache;
 };
 typedef struct mca_btl_ofi_module_t mca_btl_ofi_module_t;
 
diff --git a/opal/mca/btl/ofi/btl_ofi_component.c b/opal/mca/btl/ofi/btl_ofi_component.c
index 6785dcc74a0..bafa29f6c9d 100644
--- a/opal/mca/btl/ofi/btl_ofi_component.c
+++ b/opal/mca/btl/ofi/btl_ofi_component.c
@@ -14,7 +14,7 @@
  *                         reserved.
  * Copyright (c) 2018-2019 Intel, Inc.  All rights reserved.
  *
- * Copyright (c) 2018-2021 Amazon.com, Inc. or its affiliates.  All Rights reserved.
+ * Copyright (c) 2018-2025 Amazon.com, Inc. or its affiliates.  All Rights reserved.
  * Copyright (c) 2020-2023 Triad National Security, LLC. All rights
  *                         reserved.
  * $COPYRIGHT$
@@ -657,7 +657,6 @@ static int mca_btl_ofi_init_device(struct fi_info *info)
     module->outstanding_rdma = 0;
     module->use_virt_addr = false;
     module->use_fi_mr_bind = false;
-    module->bypass_cache = false;
 
 #if defined(FI_HMEM)
     if (ofi_info->caps & FI_HMEM) {
@@ -674,13 +673,6 @@ static int mca_btl_ofi_init_device(struct fi_info *info)
         module->use_fi_mr_bind = true;
     }
 
-    /* Currently there is no API to query whether the libfabric provider
-     * uses an underlying registration cache. For now, just check for known
-     * providers that use registration caching. */
-    if (!strncasecmp(info->fabric_attr->prov_name, "efa", 3)) {
-        module->bypass_cache = true;
-    }
-
     /* create endpoint list */
     OBJ_CONSTRUCT(&module->endpoints, opal_list_t);
     OBJ_CONSTRUCT(&module->module_lock, opal_mutex_t);
diff --git a/opal/mca/btl/ofi/btl_ofi_module.c b/opal/mca/btl/ofi/btl_ofi_module.c
index e213d5b1865..58844bee018 100644
--- a/opal/mca/btl/ofi/btl_ofi_module.c
+++ b/opal/mca/btl/ofi/btl_ofi_module.c
@@ -14,7 +14,7 @@
  *                         reserved.
  * Copyright (c) 2018      Intel, Inc, All rights reserved
  *
- * Copyright (c) 2018      Amazon.com, Inc. or its affiliates.  All Rights reserved.
+ * Copyright (c) 2018-2025 Amazon.com, Inc. or its affiliates.  All Rights reserved.
  * Copyright (c) 2020      Google, LLC. All rights reserved.
  * Copyright (c) 2022-2024 Triad National Security, LLC. All rights
  *                         reserved.
@@ -148,6 +148,20 @@ void mca_btl_ofi_rcache_init(mca_btl_ofi_module_t *module)
     if (!module->initialized) {
         mca_rcache_base_resources_t rcache_resources;
         char *tmp;
+        int ret;
+
+        /* this must be called during single threaded part of the code and
+         * before Libfabric configures its memory monitors.  Easiest to do
+         * that before domain open.  Silently ignore not-supported errors,
+         * as they are not critical to program correctness, but only
+         * indicate that LIbfabric will have to pick a different, possibly
+         * less optimal, monitor. */
+        ret = opal_common_ofi_export_memory_monitor();
+        if (0 != ret && -FI_ENOSYS != ret) {
+            opal_output_verbose(1, opal_common_ofi.output,
+                                "Failed to inject Libfabric memory monitor: %s",
+                                fi_strerror(-ret));
+        }
 
         (void) opal_asprintf(&tmp, "ofi.%s", module->linux_device_name);
 
@@ -198,9 +212,6 @@ mca_btl_ofi_register_mem(struct mca_btl_base_module_t *btl,
     int access_flags = flags & MCA_BTL_REG_FLAG_ACCESS_ANY;
     int rc;
     uint32_t cache_flags = 0;
-    if (ofi_module->bypass_cache) {
-	   cache_flags |= MCA_RCACHE_FLAGS_CACHE_BYPASS;
-    }
 
     rc = ofi_module->rcache->rcache_register(ofi_module->rcache, base, size, cache_flags, access_flags,
                                              (mca_rcache_base_registration_t **) &reg);