diff --git a/eval_protocol/pytest/evaluation_test.py b/eval_protocol/pytest/evaluation_test.py
index b58a062a..612a47a6 100644
--- a/eval_protocol/pytest/evaluation_test.py
+++ b/eval_protocol/pytest/evaluation_test.py
@@ -239,8 +239,8 @@ def _log_eval_error(status: Status, rows: list[EvaluationRow] | None, passed: bo
                         im = kwargs["input_messages"]
                         data = [EvaluationRow(messages=dataset_messages) for dataset_messages in im]
                     elif "input_rows" in kwargs and kwargs["input_rows"] is not None:
-                        # Use pre-constructed EvaluationRow objects directly
-                        data = kwargs["input_rows"]
+                        # Deep copy pre-constructed EvaluationRow objects
+                        data = [row.model_copy(deep=True) for row in kwargs["input_rows"]]
                     else:
                         raise ValueError("No input dataset, input messages, or input rows provided")
 
diff --git a/eval_protocol/pytest/parameterize.py b/eval_protocol/pytest/parameterize.py
index 51e7ee45..030a80fb 100644
--- a/eval_protocol/pytest/parameterize.py
+++ b/eval_protocol/pytest/parameterize.py
@@ -1,5 +1,5 @@
 import inspect
-from typing import TypedDict
+from typing import TypedDict, Protocol
 from collections.abc import Callable, Sequence, Iterable, Awaitable
 
 from _pytest.mark import ParameterSet
@@ -12,6 +12,54 @@
 class PytestParametrizeArgs(TypedDict):
     argnames: Sequence[str]
     argvalues: Iterable[ParameterSet | Sequence[object] | object]
+    ids: Iterable[str] | None
+
+
+class ParameterIdGenerator(Protocol):
+    """Protocol for generating pytest parameter IDs from parameter combinations."""
+
+    def generate_id(self, combo: CombinationTuple) -> str | None:
+        """Generate an ID for a parameter combination.
+
+        Args:
+            combo: The parameter combination tuple
+
+        Returns:
+            A string ID for the combination, or None to use default pytest ID
+        """
+        ...
+
+
+class DefaultParameterIdGenerator:
+    """Default ID generator that creates meaningful IDs from parameter combinations."""
+
+    def __init__(self, max_length: int = 50):
+        """Initialize the ID generator with configuration options.
+
+        Args:
+            max_length: Maximum length of generated IDs
+        """
+        self.max_length = max_length
+
+    def generate_id(self, combo: CombinationTuple) -> str | None:
+        """Generate an ID for a parameter combination."""
+        dataset, completion_params, messages, rows, evaluation_test_kwargs = combo
+
+        # Add model name if available
+        if completion_params:
+            model = completion_params.get("model")
+            if model:
+                # Extract just the model name, not the full path
+                model_name = model.split("/")[-1] if "/" in model else model
+                id_str = f"model-{model_name}"
+
+                # Truncate if too long
+                if len(id_str) > self.max_length:
+                    id_str = id_str[: self.max_length - 3] + "..."
+
+                return id_str
+
+        return None
 
 
 def pytest_parametrize(
@@ -21,6 +69,7 @@ def pytest_parametrize(
     input_messages: Sequence[list[InputMessagesParam] | None] | None,
     input_rows: Sequence[list[EvaluationRow]] | None,
     evaluation_test_kwargs: Sequence[EvaluationInputParam | None] | None,
+    id_generator: ParameterIdGenerator | None = None,
 ) -> PytestParametrizeArgs:
     """
     This function dynamically generates pytest.mark.parametrize arguments for a given
@@ -43,10 +92,18 @@ def pytest_parametrize(
     if evaluation_test_kwargs is not None:
         argnames.append("evaluation_test_kwargs")
 
+    # Use default ID generator if none provided
+    if id_generator is None:
+        id_generator = DefaultParameterIdGenerator()
+
     argvalues: list[ParameterSet | Sequence[object] | object] = []
+    ids: list[str] = []
+
     for combo in combinations:
         dataset, cp, messages, rows, etk = combo
         param_tuple: list[object] = []
+
+        # Build parameter tuple based on what's provided
         if input_dataset is not None:
             param_tuple.append(dataset)
         if completion_params is not None:
@@ -57,14 +114,22 @@ def pytest_parametrize(
             param_tuple.append(rows)
         if evaluation_test_kwargs is not None:
             param_tuple.append(etk)
-        # do validation that the length of argnames is the same as the length of param_tuple
+
+        # Validate parameter tuple length
         if len(argnames) != len(param_tuple):
             raise ValueError(
                 f"The length of argnames ({len(argnames)}) is not the same as the length of param_tuple ({len(param_tuple)})"
             )
+
         argvalues.append(tuple(param_tuple))
 
-    return PytestParametrizeArgs(argnames=argnames, argvalues=argvalues)
+        # Generate ID for this combination
+        combo_id = id_generator.generate_id(combo)
+        if combo_id is not None:
+            ids.append(combo_id)
+
+    # Return None for ids if no IDs were generated (let pytest use defaults)
+    return PytestParametrizeArgs(argnames=argnames, argvalues=argvalues, ids=ids if ids else None)
 
 
 def create_dynamically_parameterized_wrapper(
diff --git a/tests/pytest/test_parameterized_ids.py b/tests/pytest/test_parameterized_ids.py
new file mode 100644
index 00000000..ff1726d7
--- /dev/null
+++ b/tests/pytest/test_parameterized_ids.py
@@ -0,0 +1,109 @@
+from eval_protocol.models import EvaluationRow, Message
+from eval_protocol.pytest import evaluation_test
+from eval_protocol.pytest.parameterize import DefaultParameterIdGenerator, pytest_parametrize
+from eval_protocol.pytest.generate_parameter_combinations import generate_parameter_combinations
+
+
+def test_parameterized_ids():
+    """Test that evaluation_test generates proper parameter IDs."""
+    collected_ids = []
+
+    @evaluation_test(
+        input_messages=[[[Message(role="user", content="Hello, how are you?")]]],
+        completion_params=[
+            {"model": "fireworks_ai/accounts/fireworks/models/gpt-oss-120b"},
+            {"model": "gpt-4"},
+            {"temperature": 0.5},  # No model - should not generate ID
+        ],
+    )
+    def test_parameterized_ids(row: EvaluationRow) -> EvaluationRow:
+        # Collect the row to verify it was processed
+        collected_ids.append(row.input_metadata.row_id)
+        return row
+
+    # The function should exist and be callable
+    assert test_parameterized_ids is not None
+    assert callable(test_parameterized_ids)
+
+    # Test that the decorator was applied (function should have pytest marks)
+    import pytest
+
+    marks = getattr(test_parameterized_ids, "pytestmark", [])
+    assert len(marks) > 0, "Function should have pytest marks from evaluation_test decorator"
+
+    # Verify it's a parametrize mark
+    parametrize_marks = [mark for mark in marks if hasattr(mark, "name") and mark.name == "parametrize"]
+    assert len(parametrize_marks) > 0, "Should have parametrize mark"
+
+    # Check that the parametrize mark has IDs
+    parametrize_mark = parametrize_marks[0]
+    assert hasattr(parametrize_mark, "kwargs"), "Parametrize mark should have kwargs"
+    assert "ids" in parametrize_mark.kwargs, "Should have ids in kwargs"
+
+    # Extract the IDs from the parametrize mark
+    ids = parametrize_mark.kwargs.get("ids")
+    if ids is not None:
+        # Should have IDs for models but not for temperature-only params
+        expected_ids = ["model-gpt-oss-120b", "model-gpt-4"]
+        assert list(ids) == expected_ids, f"Expected {expected_ids}, got {list(ids)}"
+
+
+def test_default_id_generator():
+    """Test the DefaultParameterIdGenerator with various model names."""
+    generator = DefaultParameterIdGenerator()
+
+    # Test with full model path
+    combo1 = (None, {"model": "fireworks_ai/accounts/fireworks/models/gpt-oss-120b"}, None, None, None)
+    id1 = generator.generate_id(combo1)
+    assert id1 == "model-gpt-oss-120b"
+
+    # Test with simple model name
+    combo2 = (None, {"model": "gpt-4"}, None, None, None)
+    id2 = generator.generate_id(combo2)
+    assert id2 == "model-gpt-4"
+
+    # Test with no model
+    combo3 = (None, {"temperature": 0.5}, None, None, None)
+    id3 = generator.generate_id(combo3)
+    assert id3 is None
+
+    # Test with None completion_params
+    combo4 = (None, None, None, None, None)
+    id4 = generator.generate_id(combo4)
+    assert id4 is None
+
+
+def test_pytest_parametrize_with_custom_id_generator():
+    """Test pytest_parametrize with a custom ID generator."""
+
+    # Create test combinations
+    combinations = [
+        (None, {"model": "gpt-4"}, None, None, None),
+        (None, {"model": "claude-3"}, None, None, None),
+        (None, {"temperature": 0.5}, None, None, None),  # No model
+    ]
+
+    # Test with default generator
+    result = pytest_parametrize(
+        combinations=combinations,
+        input_dataset=None,
+        completion_params=[{"model": "gpt-4"}, {"model": "claude-3"}, {"temperature": 0.5}],
+        input_messages=None,
+        input_rows=None,
+        evaluation_test_kwargs=None,
+    )
+
+    assert result["argnames"] == ["completion_params"]
+    assert len(list(result["argvalues"])) == 3
+    assert result["ids"] == ["model-gpt-4", "model-claude-3"]  # None for no model
+
+
+def test_id_generator_max_length():
+    """Test that ID generator respects max_length parameter."""
+    generator = DefaultParameterIdGenerator(max_length=10)
+
+    # Test with long model name
+    combo = (None, {"model": "very-long-model-name-that-exceeds-max-length"}, None, None, None)
+    id_str = generator.generate_id(combo)
+    assert id_str == "model-v..."
+    assert len(id_str) <= 10
diff --git a/tests/pytest/test_pytest_input_rows_parametrized_completion_params.py b/tests/pytest/test_pytest_input_rows_parametrized_completion_params.py
new file mode 100644
index 00000000..b06476ca
--- /dev/null
+++ b/tests/pytest/test_pytest_input_rows_parametrized_completion_params.py
@@ -0,0 +1,21 @@
+from eval_protocol.models import EvaluationRow, Message
+from eval_protocol.pytest import evaluation_test
+
+
+@evaluation_test(
+    completion_params=[{"model": "gpt-4"}, {"model": "gpt-4o"}],
+    input_rows=[[EvaluationRow(messages=[Message(role="user", content="Hello, how are you?")])]],
+    evaluation_test_kwargs=[{"seen_models": set()}],
+)
+def test_pytest_input_rows_parametrized_completion_params(row: EvaluationRow, **kwargs) -> EvaluationRow:
+    """Tests that parametrized completion params are working correctly for input_rows"""
+    seen_models = kwargs["seen_models"]
+    model = row.input_metadata.completion_params["model"]
+    if len(seen_models) == 1:
+        # assert that the other model was seen
+        if model == "gpt-4":
+            assert "gpt-4o" in seen_models
+        else:
+            assert "gpt-4" in seen_models
+    seen_models.add(model)
+    return row