diff --git a/sagemaker-core/src/sagemaker/algorithm.py b/sagemaker-core/src/sagemaker/algorithm.py
new file mode 100644
index 0000000000..a75a8dfa8f
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/algorithm.py
@@ -0,0 +1,26 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.algorithm`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.algorithm",
+    replacement="`ModelTrainer` in the sagemaker-train package",
+    v3_import="from sagemaker.train import ModelTrainer",
+)
diff --git a/sagemaker-core/src/sagemaker/automl.py b/sagemaker-core/src/sagemaker/automl.py
new file mode 100644
index 0000000000..8c2a91b7a3
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/automl.py
@@ -0,0 +1,25 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.automl`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.automl",
+    replacement="the AutoML resources under sagemaker.core",
+)
diff --git a/sagemaker-core/src/sagemaker/base_predictor.py b/sagemaker-core/src/sagemaker/base_predictor.py
new file mode 100644
index 0000000000..20d2455175
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/base_predictor.py
@@ -0,0 +1,25 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.base_predictor`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.base_predictor",
+    replacement="the Endpoint resource in the sagemaker-core package",
+)
diff --git a/sagemaker-core/src/sagemaker/core/__init__.py b/sagemaker-core/src/sagemaker/core/__init__.py
index 498c85390a..ad6225aa63 100644
--- a/sagemaker-core/src/sagemaker/core/__init__.py
+++ b/sagemaker-core/src/sagemaker/core/__init__.py
@@ -1,9 +1,17 @@
 """SageMaker Core package for low-level resource management and SDK foundations."""
+
 from sagemaker.core.utils.utils import enable_textual_rich_console_and_traceback
+from sagemaker.core.deprecations import register_removed_module_finder
 
 
 enable_textual_rich_console_and_traceback()
 
+# Install the fallback finder that gives actionable migration guidance for v2
+# modules removed in v3 but not individually tombstoned. sagemaker-core is the
+# universal dependency of every v3 package, so registering here guarantees the
+# finder is active whenever the SDK is used.
+register_removed_module_finder()
+
 # Job management
 from sagemaker.core.job import _Job  # noqa: F401
 from sagemaker.core.processing import (  # noqa: F401
diff --git a/sagemaker-core/src/sagemaker/core/deprecations.py b/sagemaker-core/src/sagemaker/core/deprecations.py
index a8ba298082..cd9cccdf6d 100644
--- a/sagemaker-core/src/sagemaker/core/deprecations.py
+++ b/sagemaker-core/src/sagemaker/core/deprecations.py
@@ -13,13 +13,127 @@
 """Module for deprecation abstractions."""
 from __future__ import absolute_import
 
+import importlib.abc
 import logging
+import sys
 import warnings
 
 logger = logging.getLogger(__name__)
 
 V2_URL = "https://sagemaker.readthedocs.io/en/stable/v2.html"
 
+# Migration guide for users moving from the v2 SDK to v3.
+V3_MIGRATION_URL = "https://github.com/aws/sagemaker-python-sdk/blob/master/migration.md"
+
+# Real top-level ``sagemaker.*`` names that ship in v3. The fallback finder must
+# never intercept these -- even when a package (e.g. sagemaker-train) is simply
+# not installed, its absence should surface the normal error, not a bogus
+# "removed in v3" message.
+_KNOWN_V3_TOPLEVEL = frozenset({"core", "train", "serve", "mlops", "lineage", "ai_registry"})
+
+
+def _emit_removed_telemetry(module):
+    """Best-effort telemetry that a removed v2 module was imported.
+
+    Imported lazily and fully guarded so that telemetry can never delay or break
+    the import/error path. See
+    ``sagemaker.core.telemetry.telemetry_logging.emit_removed_interface_telemetry``
+    for the time-bounded, opt-out-able implementation.
+    """
+    try:
+        from sagemaker.core.telemetry.telemetry_logging import (
+            emit_removed_interface_telemetry,
+        )
+
+        emit_removed_interface_telemetry(module)
+    except Exception:  # pylint: disable=W0703
+        logger.debug("Removed-interface telemetry hook failed; continuing.")
+
+
+def raise_removed_in_v3(module, replacement=None, v3_import=None):
+    """Warn and then raise an actionable error for a v2 module removed in v3.
+
+    The v2 SDK exposed top-level modules (e.g. ``sagemaker.estimator``) that no
+    longer exist in v3. Importing one would otherwise fail with a bare
+    ``ModuleNotFoundError: No module named 'sagemaker.estimator'`` that gives the
+    caller no path forward. This helper is called from lightweight "tombstone"
+    modules that stand in for those removed names: it emits a
+    ``DeprecationWarning`` and then raises a ``ModuleNotFoundError`` whose message
+    names the v3 replacement and links the migration guide.
+
+    Args:
+        module (str): The removed v2 module path, e.g. ``"sagemaker.estimator"``.
+        replacement (str): Human readable v3 replacement, e.g.
+            ``"ModelTrainer in the sagemaker-train package"``. Optional.
+        v3_import (str): The exact v3 import statement, e.g.
+            ``"from sagemaker.train import ModelTrainer"``. Quoted verbatim so the
+            caller can copy-paste it. Optional.
+
+    Raises:
+        ModuleNotFoundError: always, after emitting the deprecation warning.
+    """
+    msg = f"`{module}` was removed in the SageMaker Python SDK v3."
+    if replacement:
+        msg += f" Use {replacement}."
+    if v3_import:
+        msg += f" ({v3_import})"
+    msg += f"\nSee {V3_MIGRATION_URL} for the migration guide."
+
+    _emit_removed_telemetry(module)
+    warnings.warn(msg, DeprecationWarning, stacklevel=2)
+    logger.warning(msg)
+    raise ModuleNotFoundError(msg, name=module)
+
+
+class _RemovedV2ModuleFinder(importlib.abc.MetaPathFinder):
+    """Fallback finder that gives actionable guidance for removed v2 modules.
+
+    Curated removals ship as explicit "tombstone" modules (e.g.
+    ``sagemaker/estimator.py``) that raise a precise, per-module message. This
+    finder is the *catch-all* for every other ``sagemaker.<name>`` that existed
+    in v2 but was not individually tombstoned: instead of a bare
+    ``ModuleNotFoundError: No module named 'sagemaker.foo'``, the caller gets a
+    message that says the module is not available in v3 and points to the
+    migration guide.
+
+    It is registered by appending to ``sys.meta_path``, so it only runs *after*
+    the normal import machinery has failed to locate the module. That ordering
+    guarantees it never shadows:
+      - real v3 packages (``sagemaker.core``, ``sagemaker.train``, ...), and
+      - the curated tombstone modules, which resolve as ordinary files first.
+    """
+
+    def find_spec(self, fullname, path=None, target=None):
+        """Intercept only genuinely-missing top-level ``sagemaker.<name>`` imports."""
+        if not fullname.startswith("sagemaker."):
+            return None
+        leaf = fullname[len("sagemaker.") :]
+        # Only guard top-level names; never touch real v3 subpackages.
+        if "." in leaf or leaf in _KNOWN_V3_TOPLEVEL:
+            return None
+
+        msg = (
+            f"`{fullname}` is not available in the SageMaker Python SDK v3. "
+            "It may have been removed or moved to a new location."
+            f"\nSee {V3_MIGRATION_URL} for the migration guide."
+        )
+        _emit_removed_telemetry(fullname)
+        warnings.warn(msg, DeprecationWarning, stacklevel=2)
+        logger.warning(msg)
+        raise ModuleNotFoundError(msg, name=fullname)
+
+
+def register_removed_module_finder():
+    """Install the fallback finder for removed v2 modules (idempotent).
+
+    Appends a single ``_RemovedV2ModuleFinder`` to ``sys.meta_path`` so it acts
+    as a last resort. Safe to call multiple times -- it installs at most one
+    instance per process.
+    """
+    if any(isinstance(f, _RemovedV2ModuleFinder) for f in sys.meta_path):
+        return
+    sys.meta_path.append(_RemovedV2ModuleFinder())
+
 
 def _warn(msg, sdk_version=None):
     """Generic warning raiser referencing V2
diff --git a/sagemaker-core/src/sagemaker/core/telemetry/constants.py b/sagemaker-core/src/sagemaker/core/telemetry/constants.py
index 04231ef8a0..360e49d2a7 100644
--- a/sagemaker-core/src/sagemaker/core/telemetry/constants.py
+++ b/sagemaker-core/src/sagemaker/core/telemetry/constants.py
@@ -32,6 +32,7 @@ class Feature(Enum):
     PROCESSING = 18
     MODEL_CUSTOMIZATION_NOVA = 19
     MODEL_CUSTOMIZATION_OSS = 20
+    DEPRECATED_V2_INTERFACE = 21
 
     def __str__(self):  # pylint: disable=E0307
         """Return the feature name."""
diff --git a/sagemaker-core/src/sagemaker/core/telemetry/telemetry_logging.py b/sagemaker-core/src/sagemaker/core/telemetry/telemetry_logging.py
index 1fb0f80f00..87ffab92b8 100644
--- a/sagemaker-core/src/sagemaker/core/telemetry/telemetry_logging.py
+++ b/sagemaker-core/src/sagemaker/core/telemetry/telemetry_logging.py
@@ -16,6 +16,7 @@
 import os
 import platform
 import sys
+import threading
 from time import perf_counter
 from typing import List
 import functools
@@ -23,6 +24,7 @@
 from urllib.parse import quote
 
 import boto3
+from botocore.config import Config
 from sagemaker.core.helper.session_helper import Session
 from sagemaker.core.telemetry.attribution import _CREATED_BY_ENV_VAR
 from sagemaker.core.telemetry.resource_creation import get_resource_arn
@@ -64,6 +66,7 @@
     str(Feature.PROCESSING): 18,
     str(Feature.MODEL_CUSTOMIZATION_NOVA): 19,
     str(Feature.MODEL_CUSTOMIZATION_OSS): 20,
+    str(Feature.DEPRECATED_V2_INTERFACE): 21,
 }
 
 STATUS_TO_CODE = {
@@ -139,9 +142,7 @@ def wrapper(*args, **kwargs):
                                     FEATURE_TO_CODE[str(Feature.MODEL_CUSTOMIZATION_OSS)]
                                 )
                     except Exception:  # pylint: disable=W0703
-                        logger.debug(
-                            "Unable to determine NOVA/OSS model type for telemetry."
-                        )
+                        logger.debug("Unable to determine NOVA/OSS model type for telemetry.")
 
                 if (
                     hasattr(sagemaker_session, "sagemaker_config")
@@ -329,3 +330,145 @@ def _get_default_sagemaker_session():
     sagemaker_session = Session(boto_session=boto_session)
 
     return sagemaker_session
+
+
+# --- Session-less telemetry for removed v2 interfaces (import-time) ---
+#
+# This path resolves an AWS account id and emits a telemetry ping when a caller
+# imports a v2 interface that was removed in v3. It sends the same account-id
+# field to the same endpoint as the session-based emitter above (no new data
+# category), and honors the same TelemetryOptOut config. Because it runs at
+# IMPORT time (no sagemaker_session exists), it must be strictly best-effort and
+# must never block the import or change the error raised.
+
+# Additional env-var opt-out for the removed-interface telemetry. This is a
+# convenience fallback on top of the standard TelemetryOptOut SDK-defaults config
+# (which is honored session-lessly; see _deprecation_telemetry_opted_out).
+DEPRECATION_TELEMETRY_OPT_OUT_ENV_VAR = "SAGEMAKER_DEPRECATION_TELEMETRY_OPT_OUT"
+
+# Hard ceiling (seconds) on the entire emit so a slow credential/STS/S3 path can
+# never delay the ModuleNotFoundError the caller is about to receive.
+_DEPRECATION_TELEMETRY_BUDGET_SECONDS = 1.5
+
+# Emit at most once per removed module per process.
+_deprecation_telemetry_sent = set()
+
+
+def _deprecation_telemetry_opted_out():
+    """Return True if removed-interface telemetry is disabled.
+
+    Honors the same ``TelemetryOptOut`` SDK-defaults config the session-based
+    emitter uses, so a user who opted out of telemetry is opted out here too.
+    Because there is no ``sagemaker_session`` at import time, the config is
+    loaded session-lessly via ``load_sagemaker_config()`` and passed to
+    ``resolve_value_from_config`` through its ``sagemaker_config`` parameter.
+    The ``SAGEMAKER_DEPRECATION_TELEMETRY_OPT_OUT`` environment variable is
+    honored as an additional fallback (and short-circuit for environments where
+    loading the config is undesirable).
+    """
+    # Env var fallback first: cheap, and lets users opt out without any config
+    # file lookup on the import path.
+    if os.environ.get(DEPRECATION_TELEMETRY_OPT_OUT_ENV_VAR):
+        return True
+
+    try:
+        from sagemaker.core.config.config import load_sagemaker_config
+
+        sagemaker_config = load_sagemaker_config()
+        return bool(
+            resolve_value_from_config(
+                direct_input=None,
+                config_path=TELEMETRY_OPT_OUT_PATH,
+                default_value=False,
+                sagemaker_config=sagemaker_config,
+            )
+        )
+    except Exception:  # pylint: disable=W0703
+        # If the config cannot be loaded/resolved, do not block telemetry on it;
+        # fall back to "not opted out" (env var already checked above).
+        logger.debug("Removed-interface telemetry: could not resolve TelemetryOptOut config.")
+        return False
+
+
+def _resolve_account_and_region_sessionless():
+    """Best-effort account id + region without an existing session.
+
+    Builds a short-timeout boto3 session and calls STS. Any failure (no creds,
+    offline, IMDS timeout, STS error) yields ("NotAvailable", default region).
+    Kept small and defensive because it runs on a failing-import path.
+    """
+    account_id = "NotAvailable"
+    region = DEFAULT_AWS_REGION
+    try:
+        # Tight timeouts + no retries so a blocked IMDS/STS cannot stall us.
+        cfg = Config(connect_timeout=1, read_timeout=1, retries={"max_attempts": 0})
+        boto_session = boto3.Session()
+        region = boto_session.region_name or DEFAULT_AWS_REGION
+        sts = boto_session.client("sts", config=cfg)
+        account_id = sts.get_caller_identity().get("Account", "NotAvailable")
+    except Exception:  # pylint: disable=W0703
+        # No creds / offline / timeout / any error -> stay anonymous.
+        logger.debug("Removed-interface telemetry: account id unavailable.")
+    return account_id, region
+
+
+def _emit_removed_interface_telemetry_blocking(module):
+    """Resolve identity and send the telemetry request (runs in a worker)."""
+    account_id, region = _resolve_account_and_region_sessionless()
+    try:
+        Region(region)
+    except ValueError:
+        logger.debug("Removed-interface telemetry: unsupported region, skipping.")
+        return
+    extra = (
+        f"{module}"
+        f"&x-sdkVersion={SDK_VERSION}"
+        f"&x-env={PYTHON_VERSION}"
+        f"&x-sys={OS_NAME_VERSION}"
+    )
+    url = _construct_url(
+        accountId=account_id,
+        region=region,
+        status=str(STATUS_TO_CODE[str(Status.FAILURE)]),
+        feature=str(FEATURE_TO_CODE[str(Feature.DEPRECATED_V2_INTERFACE)]),
+        failure_reason=None,
+        failure_type=None,
+        extra_info=extra,
+    )
+    _requests_helper(url, 2)
+
+
+def emit_removed_interface_telemetry(module):
+    """Best-effort, time-bounded telemetry for importing a removed v2 module.
+
+    Emits at most once per module per process, honors
+    ``SAGEMAKER_DEPRECATION_TELEMETRY_OPT_OUT``, and is hard-capped by
+    ``_DEPRECATION_TELEMETRY_BUDGET_SECONDS`` via a worker thread so it can never
+    block or delay the caller's import. Never raises.
+
+    Args:
+        module (str): The removed v2 module path, e.g. ``"sagemaker.estimator"``.
+    """
+    try:
+        if _deprecation_telemetry_opted_out():
+            return
+        if module in _deprecation_telemetry_sent:
+            return
+        _deprecation_telemetry_sent.add(module)
+
+        def _guarded_worker():
+            # Never let a worker-thread exception surface (pytest and some
+            # runtimes report unhandled thread exceptions loudly).
+            try:
+                _emit_removed_interface_telemetry_blocking(module)
+            except Exception:  # pylint: disable=W0703
+                logger.debug("Removed-interface telemetry worker failed.")
+
+        worker = threading.Thread(target=_guarded_worker, daemon=True)
+        worker.start()
+        # Bound the wait; if the network/STS path is slow we return anyway and
+        # the daemon thread is abandoned (it dies with the process).
+        worker.join(timeout=_DEPRECATION_TELEMETRY_BUDGET_SECONDS)
+    except Exception:  # pylint: disable=W0703
+        # Telemetry must never interfere with the import/error path.
+        logger.debug("Removed-interface telemetry not emitted.")
diff --git a/sagemaker-core/src/sagemaker/estimator.py b/sagemaker-core/src/sagemaker/estimator.py
new file mode 100644
index 0000000000..f0f2c16d66
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/estimator.py
@@ -0,0 +1,26 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.estimator`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.estimator",
+    replacement="`ModelTrainer` in the sagemaker-train package",
+    v3_import="from sagemaker.train import ModelTrainer",
+)
diff --git a/sagemaker-core/src/sagemaker/model.py b/sagemaker-core/src/sagemaker/model.py
new file mode 100644
index 0000000000..1090687bcf
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/model.py
@@ -0,0 +1,26 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.model`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.model",
+    replacement="`ModelBuilder` in the sagemaker-serve package",
+    v3_import="from sagemaker.serve import ModelBuilder",
+)
diff --git a/sagemaker-core/src/sagemaker/multidatamodel.py b/sagemaker-core/src/sagemaker/multidatamodel.py
new file mode 100644
index 0000000000..6f777c5dde
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/multidatamodel.py
@@ -0,0 +1,26 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.multidatamodel`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.multidatamodel",
+    replacement="`ModelBuilder` in the sagemaker-serve package",
+    v3_import="from sagemaker.serve import ModelBuilder",
+)
diff --git a/sagemaker-core/src/sagemaker/pipeline.py b/sagemaker-core/src/sagemaker/pipeline.py
new file mode 100644
index 0000000000..04892162f7
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/pipeline.py
@@ -0,0 +1,26 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.pipeline`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.pipeline",
+    replacement="`Pipeline` in the sagemaker-mlops package",
+    v3_import="from sagemaker.mlops.pipeline import Pipeline",
+)
diff --git a/sagemaker-core/src/sagemaker/predictor.py b/sagemaker-core/src/sagemaker/predictor.py
new file mode 100644
index 0000000000..547be2b91a
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/predictor.py
@@ -0,0 +1,25 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.predictor`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.predictor",
+    replacement="the Endpoint resource in the sagemaker-core package",
+)
diff --git a/sagemaker-core/src/sagemaker/predictor_async.py b/sagemaker-core/src/sagemaker/predictor_async.py
new file mode 100644
index 0000000000..1b3b41cebc
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/predictor_async.py
@@ -0,0 +1,26 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.predictor_async`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.predictor_async",
+    replacement="`ModelBuilder.deploy` in the sagemaker-serve package",
+    v3_import="from sagemaker.serve import ModelBuilder",
+)
diff --git a/sagemaker-core/src/sagemaker/processing.py b/sagemaker-core/src/sagemaker/processing.py
new file mode 100644
index 0000000000..c9900985aa
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/processing.py
@@ -0,0 +1,26 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.processing`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.processing",
+    replacement="`DataProcessor` in the sagemaker-mlops package",
+    v3_import="from sagemaker.mlops.processing import DataProcessor",
+)
diff --git a/sagemaker-core/src/sagemaker/transformer.py b/sagemaker-core/src/sagemaker/transformer.py
new file mode 100644
index 0000000000..0fdec3e888
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/transformer.py
@@ -0,0 +1,25 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.transformer`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.transformer",
+    replacement="the TransformJob resource in the sagemaker-core package",
+)
diff --git a/sagemaker-core/src/sagemaker/tuner.py b/sagemaker-core/src/sagemaker/tuner.py
new file mode 100644
index 0000000000..50c42185ec
--- /dev/null
+++ b/sagemaker-core/src/sagemaker/tuner.py
@@ -0,0 +1,25 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Removed in v3. This module stood in the v2 SageMaker Python SDK.
+
+Importing ``sagemaker.tuner`` raises an actionable ``ModuleNotFoundError`` that
+points to the v3 replacement. See the migration guide for details.
+"""
+from __future__ import absolute_import
+
+from sagemaker.core.deprecations import raise_removed_in_v3
+
+raise_removed_in_v3(
+    module="sagemaker.tuner",
+    replacement="the hyperparameter tuning resources in the sagemaker-core package",
+)
diff --git a/sagemaker-core/tests/unit/test_removed_v2_modules.py b/sagemaker-core/tests/unit/test_removed_v2_modules.py
new file mode 100644
index 0000000000..4f1d6aa620
--- /dev/null
+++ b/sagemaker-core/tests/unit/test_removed_v2_modules.py
@@ -0,0 +1,306 @@
+# Copyright Amazon.com, Inc. or its affiliates. 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. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file 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.
+"""Tests that removed v2 modules raise actionable guidance in v3."""
+from __future__ import absolute_import
+
+import importlib
+import warnings
+
+import pytest
+
+from sagemaker.core.deprecations import (
+    raise_removed_in_v3,
+    register_removed_module_finder,
+    _RemovedV2ModuleFinder,
+    V3_MIGRATION_URL,
+)
+
+# Removed v2 module -> a substring we expect in the guidance message.
+REMOVED_MODULES = {
+    "sagemaker.estimator": "ModelTrainer",
+    "sagemaker.model": "ModelBuilder",
+    "sagemaker.predictor": "Endpoint",
+    "sagemaker.base_predictor": "Endpoint",
+    "sagemaker.predictor_async": "ModelBuilder",
+    "sagemaker.transformer": "TransformJob",
+    "sagemaker.tuner": "hyperparameter tuning",
+    "sagemaker.processing": "DataProcessor",
+    "sagemaker.pipeline": "Pipeline",
+    "sagemaker.multidatamodel": "ModelBuilder",
+    "sagemaker.automl": "AutoML",
+    "sagemaker.algorithm": "ModelTrainer",
+}
+
+
+def _fresh_import(module):
+    """Import a module fresh, bypassing any cached (failed) import state."""
+    import sys
+
+    sys.modules.pop(module, None)
+    return importlib.import_module(module)
+
+
+@pytest.mark.parametrize("module,expected", sorted(REMOVED_MODULES.items()))
+def test_removed_module_raises_actionable_error(module, expected):
+    with warnings.catch_warnings():
+        warnings.simplefilter("ignore")
+        with pytest.raises(ModuleNotFoundError) as exc:
+            _fresh_import(module)
+    message = str(exc.value)
+    assert module in message
+    assert "removed in the SageMaker Python SDK v3" in message
+    assert expected in message
+    assert V3_MIGRATION_URL in message
+
+
+@pytest.mark.parametrize("module", sorted(REMOVED_MODULES))
+def test_removed_module_emits_deprecation_warning(module):
+    with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
+        with pytest.raises(ModuleNotFoundError):
+            _fresh_import(module)
+    assert any(issubclass(x.category, DeprecationWarning) for x in w)
+
+
+def test_helper_includes_import_when_provided():
+    with warnings.catch_warnings():
+        warnings.simplefilter("ignore")
+        with pytest.raises(ModuleNotFoundError) as exc:
+            raise_removed_in_v3(
+                module="sagemaker.estimator",
+                replacement="`ModelTrainer` in the sagemaker-train package",
+                v3_import="from sagemaker.train import ModelTrainer",
+            )
+    message = str(exc.value)
+    assert "from sagemaker.train import ModelTrainer" in message
+    # ModuleNotFoundError carries the module name for tooling.
+    assert exc.value.name == "sagemaker.estimator"
+
+
+def test_helper_without_replacement_still_actionable():
+    with warnings.catch_warnings():
+        warnings.simplefilter("ignore")
+        with pytest.raises(ModuleNotFoundError) as exc:
+            raise_removed_in_v3(module="sagemaker.something")
+    message = str(exc.value)
+    assert "sagemaker.something" in message
+    assert V3_MIGRATION_URL in message
+
+
+# --- Fallback finder (catch-all for non-tombstoned removed modules) ---
+
+
+def test_finder_is_registered_on_meta_path():
+    import sys
+    import sagemaker.core  # noqa: F401  -- import registers the finder
+
+    assert any(isinstance(f, _RemovedV2ModuleFinder) for f in sys.meta_path)
+
+
+def test_register_is_idempotent():
+    import sys
+
+    register_removed_module_finder()
+    register_removed_module_finder()
+    finders = [f for f in sys.meta_path if isinstance(f, _RemovedV2ModuleFinder)]
+    assert len(finders) == 1
+
+
+def test_finder_is_appended_not_prepended():
+    # As a last resort it must sit at the end so real/tombstone modules resolve
+    # first. Being in the second half of meta_path is a sufficient proxy.
+    import sys
+
+    register_removed_module_finder()
+    idx = next(i for i, f in enumerate(sys.meta_path) if isinstance(f, _RemovedV2ModuleFinder))
+    assert idx >= len(sys.meta_path) // 2
+
+
+@pytest.mark.parametrize("module", ["sagemaker.clarify", "sagemaker.session", "sagemaker.network"])
+def test_uncovered_module_falls_back_to_guidance(module):
+    import sagemaker.core  # noqa: F401  -- ensure finder registered
+
+    with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
+        with pytest.raises(ModuleNotFoundError) as exc:
+            _fresh_import(module)
+    message = str(exc.value)
+    assert module in message
+    assert "not available in the SageMaker Python SDK v3" in message
+    assert V3_MIGRATION_URL in message
+    assert any(issubclass(x.category, DeprecationWarning) for x in w)
+
+
+@pytest.mark.parametrize("module", ["sagemaker.core", "sagemaker.train", "sagemaker.serve"])
+def test_finder_does_not_shadow_real_v3_packages(module):
+    import sagemaker.core  # noqa: F401  -- ensure finder registered
+
+    # Real v3 packages must import cleanly, untouched by the fallback finder.
+    _fresh_import(module)
+
+
+def test_finder_ignores_non_sagemaker_and_nested():
+    import sagemaker.core  # noqa: F401
+
+    finder = _RemovedV2ModuleFinder()
+    # Not a sagemaker module -> pass through (None).
+    assert finder.find_spec("numpy") is None
+    # Nested path under a (removed) top-level -> only the top-level is guarded.
+    assert finder.find_spec("sagemaker.workflow.steps") is None
+    # Real v3 top-level -> never guarded.
+    assert finder.find_spec("sagemaker.train") is None
+
+
+# --- Removed-interface telemetry (session-less, import-time) ---
+
+
+@pytest.fixture(autouse=True)
+def _reset_telemetry_state(monkeypatch):
+    """Isolate telemetry dedup + opt-out env var per test.
+
+    Also neutralize the actual network/STS emit by default so the suite is
+    hermetic and fast; tests that assert telemetry behavior re-patch as needed.
+    """
+    import sagemaker.core.telemetry.telemetry_logging as tl
+
+    monkeypatch.delenv(tl.DEPRECATION_TELEMETRY_OPT_OUT_ENV_VAR, raising=False)
+    tl._deprecation_telemetry_sent.clear()
+    monkeypatch.setattr(tl, "_emit_removed_interface_telemetry_blocking", lambda module: None)
+    yield
+    tl._deprecation_telemetry_sent.clear()
+
+
+def test_telemetry_emitted_once_per_module(monkeypatch):
+    import sagemaker.core.telemetry.telemetry_logging as tl
+
+    calls = []
+    # Stop before any network/STS: record invocations of the blocking worker.
+    monkeypatch.setattr(
+        tl, "_emit_removed_interface_telemetry_blocking", lambda module: calls.append(module)
+    )
+    tl.emit_removed_interface_telemetry("sagemaker.estimator")
+    tl.emit_removed_interface_telemetry("sagemaker.estimator")
+    tl.emit_removed_interface_telemetry("sagemaker.transformer")
+    assert calls == ["sagemaker.estimator", "sagemaker.transformer"]
+
+
+def test_telemetry_opt_out_env_var(monkeypatch):
+    import sagemaker.core.telemetry.telemetry_logging as tl
+
+    calls = []
+    monkeypatch.setattr(
+        tl, "_emit_removed_interface_telemetry_blocking", lambda module: calls.append(module)
+    )
+    monkeypatch.setenv(tl.DEPRECATION_TELEMETRY_OPT_OUT_ENV_VAR, "1")
+    tl.emit_removed_interface_telemetry("sagemaker.estimator")
+    assert calls == []
+
+
+def test_telemetry_honors_config_opt_out(monkeypatch):
+    """A user who set TelemetryOptOut in SDK config is opted out here too."""
+    import sagemaker.core.telemetry.telemetry_logging as tl
+    from sagemaker.core.config import config as core_config
+
+    calls = []
+    monkeypatch.setattr(
+        tl, "_emit_removed_interface_telemetry_blocking", lambda module: calls.append(module)
+    )
+    # No env var set; opt-out comes purely from config.
+    monkeypatch.delenv(tl.DEPRECATION_TELEMETRY_OPT_OUT_ENV_VAR, raising=False)
+    monkeypatch.setattr(
+        core_config,
+        "load_sagemaker_config",
+        lambda *a, **k: {
+            "SchemaVersion": "1.0",
+            "SageMaker": {"PythonSDK": {"Modules": {"TelemetryOptOut": True}}},
+        },
+    )
+    tl.emit_removed_interface_telemetry("sagemaker.estimator")
+    assert calls == []
+
+
+def test_telemetry_config_load_failure_does_not_block(monkeypatch):
+    """If config loading fails, telemetry still proceeds (not opted out)."""
+    import sagemaker.core.telemetry.telemetry_logging as tl
+    from sagemaker.core.config import config as core_config
+
+    calls = []
+    monkeypatch.setattr(
+        tl, "_emit_removed_interface_telemetry_blocking", lambda module: calls.append(module)
+    )
+    monkeypatch.delenv(tl.DEPRECATION_TELEMETRY_OPT_OUT_ENV_VAR, raising=False)
+
+    def _boom(*a, **k):
+        raise RuntimeError("bad config")
+
+    monkeypatch.setattr(core_config, "load_sagemaker_config", _boom)
+    tl.emit_removed_interface_telemetry("sagemaker.estimator")
+    assert calls == ["sagemaker.estimator"]
+
+
+def test_telemetry_never_raises(monkeypatch):
+    import sagemaker.core.telemetry.telemetry_logging as tl
+
+    def boom(module):
+        raise RuntimeError("network exploded")
+
+    monkeypatch.setattr(tl, "_emit_removed_interface_telemetry_blocking", boom)
+    # Must swallow the worker error; the caller must never see it.
+    tl.emit_removed_interface_telemetry("sagemaker.estimator")
+
+
+def test_telemetry_is_time_bounded(monkeypatch):
+    import time
+    import sagemaker.core.telemetry.telemetry_logging as tl
+
+    monkeypatch.setattr(tl, "_DEPRECATION_TELEMETRY_BUDGET_SECONDS", 0.2)
+    monkeypatch.setattr(
+        tl, "_emit_removed_interface_telemetry_blocking", lambda module: time.sleep(5)
+    )
+    start = time.perf_counter()
+    tl.emit_removed_interface_telemetry("sagemaker.estimator")
+    elapsed = time.perf_counter() - start
+    # Bounded by the budget, not the 5s sleep.
+    assert elapsed < 1.0
+
+
+def test_account_resolution_defaults_when_unavailable(monkeypatch):
+    import sagemaker.core.telemetry.telemetry_logging as tl
+
+    class _BoomSession:
+        region_name = None
+
+        def client(self, *a, **k):
+            raise RuntimeError("no creds")
+
+    monkeypatch.setattr(tl.boto3, "Session", lambda *a, **k: _BoomSession())
+    account_id, region = tl._resolve_account_and_region_sessionless()
+    assert account_id == "NotAvailable"
+    assert region == tl.DEFAULT_AWS_REGION
+
+
+def test_removed_import_triggers_telemetry_hook(monkeypatch):
+    """End-to-end: importing a removed module invokes the telemetry hook."""
+    import importlib
+    import sys
+    import sagemaker.core  # noqa: F401  -- ensures finder + telemetry loaded
+    import sagemaker.core.deprecations as dep
+
+    seen = []
+    monkeypatch.setattr(dep, "_emit_removed_telemetry", lambda module: seen.append(module))
+    with warnings.catch_warnings():
+        warnings.simplefilter("ignore")
+        sys.modules.pop("sagemaker.estimator", None)
+        with pytest.raises(ModuleNotFoundError):
+            importlib.import_module("sagemaker.estimator")
+    assert "sagemaker.estimator" in seen