diff --git a/dataconnect/client.py b/dataconnect/client.py
index 637121e..9473a30 100644
--- a/dataconnect/client.py
+++ b/dataconnect/client.py
@@ -43,9 +43,9 @@ def connect(
 
     # Public API
 
-    def get_studies(self) -> list[Study]:
+    def get_studies(self, search_study_name: str | None = None) -> list[Study]:
         """List the studies the client is authorized to access."""
-        return self._service.get_studies()
+        return self._service.get_studies(search_study_name=search_study_name)
 
     def get_dataset_versions(self, dataset_uuid: UUID) -> list[DatasetVersion]:
         """List the dataset versions the client is authorized to access."""
diff --git a/dataconnect/service/base.py b/dataconnect/service/base.py
index 938c6a9..338d340 100644
--- a/dataconnect/service/base.py
+++ b/dataconnect/service/base.py
@@ -12,7 +12,7 @@ class DataConnectService(ABC):
     """Abstract service interface — defines all operations available to the client."""
 
     @abstractmethod
-    def get_studies(self) -> list[Study]: ...
+    def get_studies(self, search_study_name: str | None = None) -> list[Study]: ...
 
     @abstractmethod
     def get_dataset_versions(self, dataset_uuid: UUID) -> list[DatasetVersion]: ...
diff --git a/dataconnect/service/default.py b/dataconnect/service/default.py
index 204586f..5272ea8 100644
--- a/dataconnect/service/default.py
+++ b/dataconnect/service/default.py
@@ -17,6 +17,7 @@
 from dataconnect.models import DatasetVersion, Study
 from dataconnect.service.base import DataConnectService
 from dataconnect.service.mappers import resource_to_dataset_version, resource_to_study
+from dataconnect.service.validators import validate_search_study_name
 from dataconnect.transport.base import Transport
 from dataconnect.transport.errors import (
     TransportAuthenticationError,
@@ -61,9 +62,13 @@ def __init__(self, transport: Transport) -> None:
 
     # DataConnectService
 
-    def get_studies(self) -> list[Study]:
+    def get_studies(self, search_study_name: str | None = None) -> list[Study]:
+
+        validate_search_study_name(search_study_name)
 
         request = ResourceQuery(action=_ACTION_LIST_STUDIES)
+        if search_study_name and search_study_name.strip() != "":
+            request = request.append_body({"search_study_name": search_study_name})
 
         try:
             resources = self._transport.list_resources(request)
diff --git a/dataconnect/service/validators.py b/dataconnect/service/validators.py
new file mode 100644
index 0000000..5909d36
--- /dev/null
+++ b/dataconnect/service/validators.py
@@ -0,0 +1,15 @@
+"""Input validation helpers for service-layer operations."""
+
+from __future__ import annotations
+
+from dataconnect.exceptions import ValidationError
+
+
+def validate_search_study_name(search_study_name: str | None) -> None:
+    """Validate optional study-name filter used by ``get_studies``."""
+
+    if not search_study_name:
+        return
+
+    if not isinstance(search_study_name, str):
+        raise ValidationError("search_study_name must be a string")
diff --git a/tests/test_client.py b/tests/test_client.py
index 38b1563..92ad150 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -28,13 +28,6 @@ def close(self) -> None:
         self.closed += 1
 
 
-def test_get_studies_returns_service_result() -> None:
-    studies = [Study(uuid=UUID("64a98a9b-1512-44c8-92af-e4cab0183670"), name="Study A")]
-    client = DataConnectClient(_FakeService(studies=studies))
-
-    assert client.get_studies() == studies
-
-
 def test_get_dataset_versions_forwards_uuid_to_service() -> None:
     dataset_uuid = UUID("073410b6-79be-3e7d-ae37-92f6e054013e")
     versions = [
@@ -109,3 +102,45 @@ def close(self) -> None:
 def test_dummy_benchmark() -> None:
     # Dummy benchmark test to satisfy CI
     assert True
+
+
+class StubService:
+    def __init__(self) -> None:
+        self.search_study_name: str | None = None
+        self.was_closed = False
+
+    def get_studies(self, search_study_name: str | None = None) -> list[Study]:
+        self.search_study_name = search_study_name
+        return []
+
+    def close(self) -> None:
+        self.was_closed = True
+
+
+def test_get_studies_without_filter_delegates_to_service() -> None:
+    service = StubService()
+    client = DataConnectClient(service)
+
+    studies = client.get_studies()
+
+    assert studies == []
+    assert service.search_study_name is None
+
+
+def test_get_studies_with_filter_delegates_to_service() -> None:
+    service = StubService()
+    client = DataConnectClient(service)
+
+    studies = client.get_studies(search_study_name="cardio")
+
+    assert studies == []
+    assert service.search_study_name == "cardio"
+
+
+def test_close_delegates_to_service() -> None:
+    service = StubService()
+    client = DataConnectClient(service)
+
+    client.close()
+
+    assert service.was_closed
diff --git a/tests/test_service_default.py b/tests/test_service_default.py
new file mode 100644
index 0000000..d1ac135
--- /dev/null
+++ b/tests/test_service_default.py
@@ -0,0 +1,77 @@
+from __future__ import annotations
+
+import pytest
+
+from dataconnect.exceptions import ValidationError
+from dataconnect.service.default import DefaultDataConnectService
+from dataconnect.transport.models import DataRef, ResourceInfo, ResourceQuery
+
+
+class StubTransport:
+    def __init__(self, resources: list[ResourceInfo]) -> None:
+        self.resources = resources
+        self.last_request: ResourceQuery | None = None
+
+    def list_resources(self, request: ResourceQuery) -> list[ResourceInfo]:
+        self.last_request = request
+        return self.resources
+
+    def close(self) -> None:
+        return None
+
+
+def _study_resource(name: str = "Study A") -> ResourceInfo:
+    payload = (f'{{"uuid":"12345678-1234-1234-1234-123456789abc","name":"{name}","environments":[]}}').encode()
+
+    return ResourceInfo(
+        descriptor=b"",
+        endpoints=[DataRef(ticket=payload)],
+        total_records=1,
+        schema_bytes=b"",
+    )
+
+
+def test_get_studies_without_search_name_uses_empty_request_body() -> None:
+    transport = StubTransport(resources=[_study_resource()])
+    service = DefaultDataConnectService(transport)
+
+    studies = service.get_studies()
+
+    assert len(studies) == 1
+    assert studies[0].name == "Study A"
+    assert transport.last_request is not None
+    assert transport.last_request.action == "studies.list"
+    assert transport.last_request.body == ""
+
+
+def test_get_studies_with_search_name_sets_request_body() -> None:
+    transport = StubTransport(resources=[_study_resource("Cardio Study")])
+    service = DefaultDataConnectService(transport)
+
+    studies = service.get_studies(search_study_name="Cardio")
+
+    assert len(studies) == 1
+    assert studies[0].name == "Cardio Study"
+    assert transport.last_request is not None
+    assert transport.last_request.body == '{"search_study_name":"Cardio"}'
+
+
+def test_get_studies_rejects_non_string_search_name() -> None:
+    transport = StubTransport(resources=[])
+    service = DefaultDataConnectService(transport)
+
+    with pytest.raises(ValidationError, match="search_study_name must be a string"):
+        service.get_studies(search_study_name=123)  # type: ignore[arg-type]
+
+    assert transport.last_request is None
+
+
+def test_get_studies_accepts_none_search_name() -> None:
+    transport = StubTransport(resources=[_study_resource()])
+    service = DefaultDataConnectService(transport)
+
+    studies = service.get_studies(search_study_name=None)
+
+    assert len(studies) == 1
+    assert transport.last_request is not None
+    assert transport.last_request.body == ""