diff --git a/.gitignore b/.gitignore
index 7d2b20a..bfc52e9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,4 +31,6 @@ dist/
 .kiro/
 
 /examples/build/*
-/examples/*.zip
\ No newline at end of file
+/examples/*.zip
+
+.env
\ No newline at end of file
diff --git a/examples/examples-catalog.json b/examples/examples-catalog.json
index e80e3ba..fb9ab78 100644
--- a/examples/examples-catalog.json
+++ b/examples/examples-catalog.json
@@ -580,6 +580,28 @@
           "ApplicationLogLevel": "DEBUG",
           "LogFormat": "JSON"
         }
-      }
+      },
+    {
+      "name": "Map with Item Namer",
+      "description": "Map operation with custom item_namer for iteration naming",
+      "handler": "map_with_item_namer.handler",
+      "integration": true,
+      "durableConfig": {
+        "RetentionPeriodInDays": 7,
+        "ExecutionTimeout": 300
+      },
+      "path": "./src/map/map_with_item_namer.py"
+    },
+    {
+      "name": "Parallel with Named Branches",
+      "description": "Parallel operation with named branches using ParallelBranch",
+      "handler": "parallel_with_named_branches.handler",
+      "integration": true,
+      "durableConfig": {
+        "RetentionPeriodInDays": 7,
+        "ExecutionTimeout": 300
+      },
+      "path": "./src/parallel/parallel_with_named_branches.py"
+    }
   ]
 }
diff --git a/examples/src/map/map_with_item_namer.py b/examples/src/map/map_with_item_namer.py
new file mode 100644
index 0000000..331faab
--- /dev/null
+++ b/examples/src/map/map_with_item_namer.py
@@ -0,0 +1,30 @@
+"""Example demonstrating map operations with custom iteration naming."""
+
+from typing import Any
+
+from aws_durable_execution_sdk_python.config import MapConfig
+from aws_durable_execution_sdk_python.context import DurableContext
+from aws_durable_execution_sdk_python.execution import durable_execution
+
+
+@durable_execution
+def handler(_event: Any, context: DurableContext) -> list[str]:
+    """Process orders using context.map() with custom iteration names."""
+    orders = [
+        {"id": "order-101", "amount": 25},
+        {"id": "order-102", "amount": 50},
+        {"id": "order-103", "amount": 75},
+    ]
+
+    return context.map(
+        inputs=orders,
+        func=lambda ctx, order, index, _: ctx.step(
+            lambda _: f"processed-{order['id']}-${order['amount']}",
+            name=f"process_{order['id']}",
+        ),
+        name="process_orders",
+        config=MapConfig(
+            max_concurrency=2,
+            item_namer=lambda order, index: f"order-{order['id']}",
+        ),
+    ).get_results()
diff --git a/examples/src/parallel/parallel_with_named_branches.py b/examples/src/parallel/parallel_with_named_branches.py
new file mode 100644
index 0000000..78340a1
--- /dev/null
+++ b/examples/src/parallel/parallel_with_named_branches.py
@@ -0,0 +1,35 @@
+"""Example demonstrating parallel operations with named branches."""
+
+from typing import Any
+
+from aws_durable_execution_sdk_python.config import ParallelBranch, ParallelConfig
+from aws_durable_execution_sdk_python.context import DurableContext
+from aws_durable_execution_sdk_python.execution import durable_execution
+
+
+@durable_execution
+def handler(_event: Any, context: DurableContext) -> list[str]:
+    """Execute named parallel branches using ParallelBranch."""
+
+    return context.parallel(
+        functions=[
+            ParallelBranch(
+                func=lambda ctx: ctx.step(
+                    lambda _: "user-data-loaded", name="load_user"
+                ),
+                name="fetch-user-data",
+            ),
+            ParallelBranch(
+                func=lambda ctx: ctx.step(
+                    lambda _: "orders-loaded", name="load_orders"
+                ),
+                name="fetch-order-history",
+            ),
+            ParallelBranch(
+                func=lambda ctx: ctx.step(lambda _: "prefs-loaded", name="load_prefs"),
+                name="fetch-preferences",
+            ),
+        ],
+        name="load_all_data",
+        config=ParallelConfig(max_concurrency=3),
+    ).get_results()
diff --git a/examples/template.yaml b/examples/template.yaml
index 0a9dcb9..2854e72 100644
--- a/examples/template.yaml
+++ b/examples/template.yaml
@@ -941,6 +941,42 @@
           "ExecutionTimeout": 300
         }
       }
+    },
+    "MapWithItemNamer": {
+      "Type": "AWS::Serverless::Function",
+      "Properties": {
+        "CodeUri": "build/",
+        "Handler": "map_with_item_namer.handler",
+        "Description": "Map operation with custom item_namer for iteration naming",
+        "Role": {
+          "Fn::GetAtt": [
+            "DurableFunctionRole",
+            "Arn"
+          ]
+        },
+        "DurableConfig": {
+          "RetentionPeriodInDays": 7,
+          "ExecutionTimeout": 300
+        }
+      }
+    },
+    "ParallelWithNamedBranches": {
+      "Type": "AWS::Serverless::Function",
+      "Properties": {
+        "CodeUri": "build/",
+        "Handler": "parallel_with_named_branches.handler",
+        "Description": "Parallel operation with named branches using ParallelBranch",
+        "Role": {
+          "Fn::GetAtt": [
+            "DurableFunctionRole",
+            "Arn"
+          ]
+        },
+        "DurableConfig": {
+          "RetentionPeriodInDays": 7,
+          "ExecutionTimeout": 300
+        }
+      }
     }
   }
 }
\ No newline at end of file
diff --git a/examples/test/map/test_map_with_item_namer.py b/examples/test/map/test_map_with_item_namer.py
new file mode 100644
index 0000000..11997d8
--- /dev/null
+++ b/examples/test/map/test_map_with_item_namer.py
@@ -0,0 +1,39 @@
+"""Tests for map_with_item_namer example."""
+
+import pytest
+from src.map import map_with_item_namer
+from test.conftest import deserialize_operation_payload
+
+from aws_durable_execution_sdk_python.execution import InvocationStatus
+from aws_durable_execution_sdk_python.lambda_service import (
+    OperationStatus,
+)
+
+
+@pytest.mark.example
+@pytest.mark.durable_execution(
+    handler=map_with_item_namer.handler,
+    lambda_function_name="map with item namer",
+)
+def test_map_with_item_namer(durable_runner):
+    """Test map example with custom item_namer for iteration naming."""
+    with durable_runner:
+        result = durable_runner.run(input="test", timeout=10)
+
+    assert result.status is InvocationStatus.SUCCEEDED
+    assert deserialize_operation_payload(result.result) == [
+        "processed-order-101-$25",
+        "processed-order-102-$50",
+        "processed-order-103-$75",
+    ]
+
+    # Get the map operation
+    map_op = result.get_context("process_orders")
+    assert map_op is not None
+    assert map_op.status is OperationStatus.SUCCEEDED
+
+    # Verify custom iteration names from item_namer
+    assert len(map_op.child_operations) == 3
+    child_names = {op.name for op in map_op.child_operations}
+    expected_names = {"order-order-101", "order-order-102", "order-order-103"}
+    assert child_names == expected_names
diff --git a/examples/test/parallel/test_parallel_with_named_branches.py b/examples/test/parallel/test_parallel_with_named_branches.py
new file mode 100644
index 0000000..61a8ee9
--- /dev/null
+++ b/examples/test/parallel/test_parallel_with_named_branches.py
@@ -0,0 +1,45 @@
+"""Tests for parallel_with_named_branches example."""
+
+import pytest
+from src.parallel import parallel_with_named_branches
+from test.conftest import deserialize_operation_payload
+
+from aws_durable_execution_sdk_python.execution import InvocationStatus
+from aws_durable_execution_sdk_python.lambda_service import (
+    OperationStatus,
+    OperationType,
+)
+
+
+@pytest.mark.example
+@pytest.mark.durable_execution(
+    handler=parallel_with_named_branches.handler,
+    lambda_function_name="parallel with named branches",
+)
+def test_parallel_with_named_branches(durable_runner):
+    """Test parallel example with named branches using ParallelBranch."""
+    with durable_runner:
+        result = durable_runner.run(input="test", timeout=10)
+
+    assert result.status is InvocationStatus.SUCCEEDED
+    assert deserialize_operation_payload(result.result) == [
+        "user-data-loaded",
+        "orders-loaded",
+        "prefs-loaded",
+    ]
+
+    # Get the parallel operation
+    parallel_op = result.get_context("load_all_data")
+    assert parallel_op is not None
+    assert parallel_op.status is OperationStatus.SUCCEEDED
+
+    # Verify custom branch names from ParallelBranch
+    assert len(parallel_op.child_operations) == 3
+    child_names = {op.name for op in parallel_op.child_operations}
+    expected_names = {"fetch-user-data", "fetch-order-history", "fetch-preferences"}
+    assert child_names == expected_names
+
+    # Verify all children succeeded
+    for child in parallel_op.child_operations:
+        assert child.operation_type == OperationType.CONTEXT
+        assert child.status is OperationStatus.SUCCEEDED
diff --git a/src/aws_durable_execution_sdk_python/__init__.py b/src/aws_durable_execution_sdk_python/__init__.py
index 23a85cd..fc2a657 100644
--- a/src/aws_durable_execution_sdk_python/__init__.py
+++ b/src/aws_durable_execution_sdk_python/__init__.py
@@ -7,6 +7,7 @@
 # Helper decorators - commonly used for step functions
 # Concurrency
 from aws_durable_execution_sdk_python.concurrency.models import BatchResult
+from aws_durable_execution_sdk_python.config import ParallelBranch
 from aws_durable_execution_sdk_python.context import (
     DurableContext,
     durable_step,
@@ -27,11 +28,13 @@
 # Essential context types - passed to user functions
 from aws_durable_execution_sdk_python.types import StepContext
 
+
 __all__ = [
     "BatchResult",
     "DurableContext",
     "DurableExecutionsError",
     "InvocationError",
+    "ParallelBranch",
     "StepContext",
     "ValidationError",
     "__version__",
diff --git a/src/aws_durable_execution_sdk_python/concurrency/executor.py b/src/aws_durable_execution_sdk_python/concurrency/executor.py
index 24c7657..3a7ab13 100644
--- a/src/aws_durable_execution_sdk_python/concurrency/executor.py
+++ b/src/aws_durable_execution_sdk_python/concurrency/executor.py
@@ -194,6 +194,14 @@ def execute_item(
         """Execute a single executable in a child context and return the result."""
         raise NotImplementedError
 
+    def get_iteration_name(self, index: int) -> str:
+        """Get the display name for an iteration/branch at the given index.
+
+        Subclasses can override this to provide custom naming (e.g., from item_namer
+        or branch names). The default returns "{name_prefix}{index}".
+        """
+        return f"{self.name_prefix}{index}"
+
     def execute(
         self, execution_state: ExecutionState, executor_context: DurableContext
     ) -> BatchResult[ResultType]:
@@ -410,7 +418,7 @@ def _execute_item_in_child_context(
         operation_id: str = executor_context._create_step_id_for_logical_step(  # noqa: SLF001
             executable.index
         )
-        name: str = f"{self.name_prefix}{executable.index}"
+        name: str = self.get_iteration_name(executable.index)
         is_virtual: bool = self.nesting_type is NestingType.FLAT
 
         child_context: DurableContext = executor_context.create_child_context(
diff --git a/src/aws_durable_execution_sdk_python/config.py b/src/aws_durable_execution_sdk_python/config.py
index 980786d..e8c0eb4 100644
--- a/src/aws_durable_execution_sdk_python/config.py
+++ b/src/aws_durable_execution_sdk_python/config.py
@@ -9,6 +9,7 @@
 
 from aws_durable_execution_sdk_python.exceptions import ValidationError
 
+
 P = TypeVar("P")  # Payload type
 R = TypeVar("R")  # Result type
 T = TypeVar("T")
@@ -245,6 +246,41 @@ class ParallelConfig:
     nesting_type: NestingType = NestingType.NESTED
 
 
+@dataclass(frozen=True)
+class ParallelBranch(Generic[T]):
+    """A named branch for parallel execution.
+
+    Use this to provide custom names for parallel branches, improving
+    observability in execution history.
+
+    Type Parameters:
+        T: The return type of the branch function.
+
+    Args:
+        func: The callable to execute in this branch. Receives a DurableContext.
+        name: Optional custom name for this branch. When provided, replaces
+            the default "parallel-branch-{index}" naming in execution history.
+            This affects observability but not replay determinism.
+
+    Example:
+        context.parallel(
+            functions=[
+                ParallelBranch(func=lambda ctx: fetch_user(ctx), name="fetch-user-data"),
+                ParallelBranch(func=lambda ctx: fetch_orders(ctx), name="fetch-order-history"),
+            ],
+            name="load-data",
+            config=ParallelConfig(max_concurrency=2),
+        )
+    """
+
+    func: Callable
+    name: str | None = None
+
+    def __call__(self, *args, **kwargs):
+        """Delegate to the wrapped function, making ParallelBranch itself callable."""
+        return self.func(*args, **kwargs)
+
+
 class StepSemantics(Enum):
     AT_MOST_ONCE_PER_RETRY = "AT_MOST_ONCE_PER_RETRY"
     AT_LEAST_ONCE_PER_RETRY = "AT_LEAST_ONCE_PER_RETRY"
@@ -354,12 +390,15 @@ class ItemBatcher(Generic[T]):
 
 
 @dataclass(frozen=True)
-class MapConfig:
+class MapConfig(Generic[T]):
     """Configuration options for map operations over collections.
 
     This class configures how map operations process collections of items,
     including concurrency, batching, completion criteria, and serialization.
 
+    Type Parameters:
+        T: The type of items being processed in the map operation.
+
     Args:
         max_concurrency: Maximum number of items to process concurrently.
             If None, no limit is imposed and all items are processed concurrently.
@@ -402,6 +441,12 @@ class MapConfig:
             - NESTED: Each item runs in its own isolated context (default)
             - FLAT: All items share the same parent context
 
+        item_namer: Optional callable to generate custom names for each map iteration.
+            When provided, replaces the default "map-item-{index}" naming scheme.
+            Receives the item and its index, and returns a string name for that iteration.
+            This affects observability (execution history names) but not replay determinism.
+            If None, uses the default naming: "map-item-{index}".
+
     Example:
         # Process 5 items at a time, batch by count, require all to succeed
         config = MapConfig(
@@ -409,6 +454,12 @@ class MapConfig:
             item_batcher=ItemBatcher(max_items_per_batch=10),
             completion_config=CompletionConfig.all_successful()
         )
+
+        # With custom iteration names
+        config = MapConfig(
+            max_concurrency=5,
+            item_namer=lambda item, index: f"process-order-{item.id}"
+        )
     """
 
     max_concurrency: int | None = None
@@ -418,6 +469,7 @@ class MapConfig:
     item_serdes: SerDes | None = None
     summary_generator: SummaryGenerator | None = None
     nesting_type: NestingType = NestingType.NESTED
+    item_namer: Callable[[T, int], str] | None = None
 
 
 @dataclass(frozen=True)
diff --git a/src/aws_durable_execution_sdk_python/context.py b/src/aws_durable_execution_sdk_python/context.py
index bfded98..370e0d4 100644
--- a/src/aws_durable_execution_sdk_python/context.py
+++ b/src/aws_durable_execution_sdk_python/context.py
@@ -12,6 +12,7 @@
     Duration,
     InvokeConfig,
     MapConfig,
+    ParallelBranch,
     ParallelConfig,
     StepConfig,
     WaitForCallbackConfig,
@@ -55,6 +56,7 @@
     WaitForConditionCheckContext,
 )
 
+
 if TYPE_CHECKING:
     from collections.abc import Callable, Sequence
 
@@ -496,7 +498,7 @@ def map_in_child_context() -> BatchResult[R]:
 
     def parallel(
         self,
-        functions: Sequence[Callable[[DurableContext], T]],
+        functions: Sequence[Callable[[DurableContext], T] | ParallelBranch[T]],
         name: str | None = None,
         config: ParallelConfig | None = None,
     ) -> BatchResult[T]:
diff --git a/src/aws_durable_execution_sdk_python/operation/map.py b/src/aws_durable_execution_sdk_python/operation/map.py
index 8e9fb6a..f201efc 100644
--- a/src/aws_durable_execution_sdk_python/operation/map.py
+++ b/src/aws_durable_execution_sdk_python/operation/map.py
@@ -15,6 +15,7 @@
 from aws_durable_execution_sdk_python.config import MapConfig, NestingType
 from aws_durable_execution_sdk_python.lambda_service import OperationSubType
 
+
 if TYPE_CHECKING:
     from aws_durable_execution_sdk_python.context import DurableContext
     from aws_durable_execution_sdk_python.identifier import OperationIdentifier
@@ -47,6 +48,7 @@ def __init__(
         summary_generator: SummaryGenerator | None = None,
         item_serdes: SerDes | None = None,
         nesting_type: NestingType = NestingType.NESTED,
+        item_namer: Callable[[T, int], str] | None = None,
     ):
         super().__init__(
             executables=executables,
@@ -61,13 +63,14 @@ def __init__(
             nesting_type=nesting_type,
         )
         self.items = items
+        self._item_namer = item_namer
 
     @classmethod
     def from_items(
         cls,
         items: Sequence[T],
         func: Callable,
-        config: MapConfig,
+        config: MapConfig[T],
     ) -> MapExecutor[T, R]:
         """Create MapExecutor from items and a callable."""
         executables: list[Executable[Callable]] = [
@@ -86,8 +89,15 @@ def from_items(
             summary_generator=config.summary_generator,
             item_serdes=config.item_serdes,
             nesting_type=config.nesting_type,
+            item_namer=config.item_namer,
         )
 
+    def get_iteration_name(self, index: int) -> str:
+        """Return custom item name if item_namer is provided, otherwise default."""
+        if self._item_namer is not None:
+            return self._item_namer(self.items[index], index)
+        return super().get_iteration_name(index)
+
     def execute_item(self, child_context, executable: Executable[Callable]) -> R:
         logger.debug("🗺️ Processing map item: %s", executable.index)
         item = self.items[executable.index]
diff --git a/src/aws_durable_execution_sdk_python/operation/parallel.py b/src/aws_durable_execution_sdk_python/operation/parallel.py
index 4d7094a..76fc16f 100644
--- a/src/aws_durable_execution_sdk_python/operation/parallel.py
+++ b/src/aws_durable_execution_sdk_python/operation/parallel.py
@@ -9,9 +9,14 @@
 
 from aws_durable_execution_sdk_python.concurrency.executor import ConcurrentExecutor
 from aws_durable_execution_sdk_python.concurrency.models import Executable
-from aws_durable_execution_sdk_python.config import ParallelConfig, NestingType
+from aws_durable_execution_sdk_python.config import (
+    NestingType,
+    ParallelBranch,
+    ParallelConfig,
+)
 from aws_durable_execution_sdk_python.lambda_service import OperationSubType
 
+
 if TYPE_CHECKING:
     from aws_durable_execution_sdk_python.concurrency.models import BatchResult
     from aws_durable_execution_sdk_python.context import DurableContext
@@ -56,13 +61,19 @@ def __init__(
     @classmethod
     def from_callables(
         cls,
-        callables: Sequence[Callable],
+        callables: Sequence[Callable | ParallelBranch],
         config: ParallelConfig,
     ) -> ParallelExecutor:
-        """Create ParallelExecutor from a sequence of callables."""
+        """Create ParallelExecutor from a sequence of callables or ParallelBranch instances.
+
+        Since ParallelBranch is callable, it is stored directly as the func in
+        each Executable. The get_iteration_name method inspects the func to
+        extract the branch name when available.
+        """
         executables: list[Executable[Callable]] = [
             Executable(index=i, func=func) for i, func in enumerate(callables)
         ]
+
         return cls(
             executables=executables,
             max_concurrency=config.max_concurrency,
@@ -76,6 +87,13 @@ def from_callables(
             nesting_type=config.nesting_type,
         )
 
+    def get_iteration_name(self, index: int) -> str:
+        """Return custom branch name if the callable is a ParallelBranch with a name."""
+        func = self.executables[index].func
+        if isinstance(func, ParallelBranch) and func.name is not None:
+            return func.name
+        return super().get_iteration_name(index)
+
     def execute_item(self, child_context, executable: Executable[Callable]) -> R:  # noqa: PLR6301
         logger.debug("🔀 Processing parallel branch: %s", executable.index)
         result: R = executable.func(child_context)
@@ -84,7 +102,7 @@ def execute_item(self, child_context, executable: Executable[Callable]) -> R:  #
 
 
 def parallel_handler(
-    callables: Sequence[Callable],
+    callables: Sequence[Callable | ParallelBranch],
     config: ParallelConfig | None,
     execution_state: ExecutionState,
     parallel_context: DurableContext,
diff --git a/src/aws_durable_execution_sdk_python/types.py b/src/aws_durable_execution_sdk_python/types.py
index 9181be9..90080b0 100644
--- a/src/aws_durable_execution_sdk_python/types.py
+++ b/src/aws_durable_execution_sdk_python/types.py
@@ -6,6 +6,7 @@
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Any, Generic, Protocol, TypeVar
 
+
 if TYPE_CHECKING:
     from collections.abc import Callable, Mapping, Sequence
 
@@ -15,6 +16,7 @@
         ChildConfig,
         Duration,
         MapConfig,
+        ParallelBranch,
         ParallelConfig,
         StepConfig,
     )
@@ -124,7 +126,7 @@ def map(
     @abstractmethod
     def parallel(
         self,
-        functions: Sequence[Callable[[DurableContext], T]],
+        functions: Sequence[Callable[[DurableContext], T] | ParallelBranch[T]],
         name: str | None = None,
         config: ParallelConfig | None = None,
     ) -> BatchResult[T]:
diff --git a/tests/operation/map_test.py b/tests/operation/map_test.py
index b3c979d..c7a653f 100644
--- a/tests/operation/map_test.py
+++ b/tests/operation/map_test.py
@@ -1178,3 +1178,122 @@ def map_func(ctx, item, idx, items):
     assert result.total_count == 0
     assert result.success_count == 0
     assert result.failure_count == 0
+
+
+# region item_namer tests
+
+
+def test_map_executor_get_iteration_name_default():
+    """Without item_namer, iterations use default 'map-item-{index}' naming."""
+    items = ["a", "b", "c"]
+    config = MapConfig(max_concurrency=2)
+
+    executor = MapExecutor.from_items(
+        items=items,
+        func=lambda ctx, item, idx, items: item,
+        config=config,
+    )
+
+    assert executor.get_iteration_name(0) == "map-item-0"
+    assert executor.get_iteration_name(1) == "map-item-1"
+    assert executor.get_iteration_name(2) == "map-item-2"
+
+
+def test_map_executor_get_iteration_name_with_item_namer():
+    """With item_namer, iterations use custom names."""
+    items = [{"id": "order-1"}, {"id": "order-2"}, {"id": "order-3"}]
+    config = MapConfig(
+        max_concurrency=2,
+        item_namer=lambda item, index: f"process-{item['id']}",
+    )
+
+    executor = MapExecutor.from_items(
+        items=items,
+        func=lambda ctx, item, idx, items: item,
+        config=config,
+    )
+
+    assert executor.get_iteration_name(0) == "process-order-1"
+    assert executor.get_iteration_name(1) == "process-order-2"
+    assert executor.get_iteration_name(2) == "process-order-3"
+
+
+def test_map_executor_item_namer_receives_item_and_index():
+    """item_namer receives both the item and its index."""
+    items = ["alpha", "beta", "gamma"]
+    received_args: list[tuple] = []
+
+    def namer(item, index):
+        received_args.append((item, index))
+        return f"item-{index}-{item}"
+
+    config = MapConfig(item_namer=namer)
+
+    executor = MapExecutor.from_items(
+        items=items,
+        func=lambda ctx, item, idx, items: item,
+        config=config,
+    )
+
+    executor.get_iteration_name(0)
+    executor.get_iteration_name(2)
+
+    assert received_args == [("alpha", 0), ("gamma", 2)]
+
+
+def test_map_executor_item_namer_uses_index():
+    """item_namer can use the index to generate names."""
+    items = [10, 20, 30]
+    config = MapConfig(item_namer=lambda item, index: f"step-{index + 1}")
+
+    executor = MapExecutor.from_items(
+        items=items,
+        func=lambda ctx, item, idx, items: item,
+        config=config,
+    )
+
+    assert executor.get_iteration_name(0) == "step-1"
+    assert executor.get_iteration_name(1) == "step-2"
+    assert executor.get_iteration_name(2) == "step-3"
+
+
+def test_map_executor_item_namer_none_falls_back_to_default():
+    """Explicitly passing item_namer=None uses default naming."""
+    items = ["x", "y"]
+    config = MapConfig(item_namer=None)
+
+    executor = MapExecutor.from_items(
+        items=items,
+        func=lambda ctx, item, idx, items: item,
+        config=config,
+    )
+
+    assert executor.get_iteration_name(0) == "map-item-0"
+    assert executor.get_iteration_name(1) == "map-item-1"
+
+
+def test_map_executor_from_items_passes_item_namer():
+    """MapExecutor.from_items correctly passes item_namer from config."""
+    namer = lambda item, index: f"custom-{index}"  # noqa: E731
+    config = MapConfig(item_namer=namer)
+
+    executor = MapExecutor.from_items(
+        items=["a"],
+        func=lambda ctx, item, idx, items: item,
+        config=config,
+    )
+
+    assert executor._item_namer is namer
+
+
+def test_map_config_generic_with_item_namer():
+    """MapConfig can be parameterized with a type and use item_namer."""
+    config: MapConfig[dict] = MapConfig(
+        item_namer=lambda item, index: f"item-{item['name']}",
+    )
+
+    assert config.item_namer is not None
+    assert config.item_namer({"name": "test"}, 0) == "item-test"
+
+
+# endregion
diff --git a/tests/operation/parallel_test.py b/tests/operation/parallel_test.py
index 1922207..cf7c736 100644
--- a/tests/operation/parallel_test.py
+++ b/tests/operation/parallel_test.py
@@ -20,8 +20,8 @@
 )
 from aws_durable_execution_sdk_python.config import (
     CompletionConfig,
-    ParallelConfig,
     NestingType,
+    ParallelConfig,
 )
 from aws_durable_execution_sdk_python.context import DurableContext, ExecutionContext
 from aws_durable_execution_sdk_python.identifier import OperationIdentifier
@@ -1118,3 +1118,123 @@ def create_id(self, i):
         assert parent_call[1]["serdes"] is custom_serdes
         assert isinstance(parent_call[1]["value"], BatchResult)
         assert parent_call[1]["value"] is result
+
+
+# region ParallelBranch and branch naming tests
+
+
+def test_parallel_branch_is_callable():
+    """ParallelBranch instances are callable."""
+    from aws_durable_execution_sdk_python.config import ParallelBranch
+
+    branch = ParallelBranch(func=lambda x: x * 2, name="double")
+    assert callable(branch)
+
+
+def test_parallel_branch_delegates_to_func():
+    """Calling ParallelBranch delegates to the wrapped func."""
+    from aws_durable_execution_sdk_python.config import ParallelBranch
+
+    branch = ParallelBranch(func=lambda x, y: x + y, name="add")
+    assert branch(3, 4) == 7
+
+
+def test_parallel_branch_passes_kwargs():
+    """ParallelBranch passes keyword arguments to func."""
+    from aws_durable_execution_sdk_python.config import ParallelBranch
+
+    branch = ParallelBranch(func=lambda ctx, flag=False: flag, name="test")
+    assert branch("ctx", flag=True) is True
+
+
+def test_parallel_branch_frozen():
+    """ParallelBranch is immutable (frozen dataclass)."""
+    from aws_durable_execution_sdk_python.config import ParallelBranch
+
+    branch = ParallelBranch(func=lambda: None, name="test")
+    with pytest.raises(AttributeError):
+        branch.name = "changed"  # type: ignore[misc]
+
+
+def test_parallel_executor_get_iteration_name_default():
+    """Plain callables use default 'parallel-branch-{index}' naming."""
+    callables = [lambda ctx: "a", lambda ctx: "b", lambda ctx: "c"]
+    config = ParallelConfig()
+
+    executor = ParallelExecutor.from_callables(callables, config)
+
+    assert executor.get_iteration_name(0) == "parallel-branch-0"
+    assert executor.get_iteration_name(1) == "parallel-branch-1"
+    assert executor.get_iteration_name(2) == "parallel-branch-2"
+
+
+def test_parallel_executor_get_iteration_name_with_named_branches():
+    """ParallelBranch with name uses the custom name."""
+    from aws_durable_execution_sdk_python.config import ParallelBranch
+
+    branches = [
+        ParallelBranch(func=lambda ctx: "user", name="fetch-user-data"),
+        ParallelBranch(func=lambda ctx: "orders", name="fetch-order-history"),
+    ]
+    config = ParallelConfig()
+
+    executor = ParallelExecutor.from_callables(branches, config)
+
+    assert executor.get_iteration_name(0) == "fetch-user-data"
+    assert executor.get_iteration_name(1) == "fetch-order-history"
+
+
+def test_parallel_executor_get_iteration_name_mixed():
+    """Mix of ParallelBranch (with/without name) and plain callables."""
+    from aws_durable_execution_sdk_python.config import ParallelBranch
+
+    branches = [
+        ParallelBranch(func=lambda ctx: "a", name="named-branch"),
+        lambda ctx: "b",
+        ParallelBranch(func=lambda ctx: "c"),
+    ]
+    config = ParallelConfig()
+
+    executor = ParallelExecutor.from_callables(branches, config)
+
+    assert executor.get_iteration_name(0) == "named-branch"
+    assert executor.get_iteration_name(1) == "parallel-branch-1"
+    assert executor.get_iteration_name(2) == "parallel-branch-2"
+
+
+def test_parallel_executor_get_iteration_name_none_name():
+    """ParallelBranch with name=None falls back to default naming."""
+    from aws_durable_execution_sdk_python.config import ParallelBranch
+
+    branches = [
+        ParallelBranch(func=lambda ctx: "x", name=None),
+    ]
+    config = ParallelConfig()
+
+    executor = ParallelExecutor.from_callables(branches, config)
+
+    assert executor.get_iteration_name(0) == "parallel-branch-0"
+
+
+def test_parallel_branch_execute_item():
+    """ParallelBranch works correctly in execute_item."""
+    from aws_durable_execution_sdk_python.config import ParallelBranch
+
+    branch = ParallelBranch(func=lambda ctx: f"result-{ctx}", name="my-branch")
+    executable = Executable(index=0, func=branch)
+
+    executor = ParallelExecutor(
+        executables=[executable],
+        max_concurrency=None,
+        completion_config=CompletionConfig.all_successful(),
+        top_level_sub_type=OperationSubType.PARALLEL,
+        iteration_sub_type=OperationSubType.PARALLEL_BRANCH,
+        name_prefix="parallel-branch-",
+        serdes=None,
+    )
+
+    result = executor.execute_item("test-ctx", executable)
+    assert result == "result-test-ctx"
+
+
+# endregion