diff --git a/miplearn/__init__.py b/miplearn/__init__.py
index 5964a12..632597b 100644
--- a/miplearn/__init__.py
+++ b/miplearn/__init__.py
@@ -14,9 +14,9 @@ from .classifiers.sklearn import (
 from .classifiers.adaptive import AdaptiveClassifier
 from .classifiers.threshold import MinPrecisionThreshold
 from .components.component import Component
-from .components.cuts import UserCutsComponent
-from .components.lazy_dynamic import DynamicLazyConstraintsComponent
-from .components.lazy_static import StaticLazyConstraintsComponent
+from .components.dynamic_lazy import DynamicLazyConstraintsComponent
+from .components.dynamic_user_cuts import UserCutsComponent
+from .components.static_lazy import StaticLazyConstraintsComponent
 from .components.objective import ObjectiveValueComponent
 from .components.primal import PrimalSolutionComponent
 from .components.steps.convert_tight import ConvertTightIneqsIntoEqsStep
diff --git a/miplearn/components/cuts.py b/miplearn/components/cuts.py
deleted file mode 100644
index 5b163c3..0000000
--- a/miplearn/components/cuts.py
+++ /dev/null
@@ -1,107 +0,0 @@
-#  MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
-#  Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved.
-#  Released under the modified BSD license. See COPYING.md for more details.
-
-import logging
-import sys
-from typing import Any, Dict
-
-import numpy as np
-from tqdm.auto import tqdm
-
-from miplearn.classifiers import Classifier
-from miplearn.classifiers.counting import CountingClassifier
-from miplearn.components import classifier_evaluation_dict
-from miplearn.components.component import Component
-from miplearn.extractors import InstanceFeaturesExtractor
-
-logger = logging.getLogger(__name__)
-
-
-class UserCutsComponent(Component):
-    """
-    A component that predicts which user cuts to enforce.
-    """
-
-    def __init__(
-        self,
-        classifier: Classifier = CountingClassifier(),
-        threshold: float = 0.05,
-    ):
-        assert isinstance(classifier, Classifier)
-        self.threshold: float = threshold
-        self.classifier_prototype: Classifier = classifier
-        self.classifiers: Dict[Any, Classifier] = {}
-
-    def before_solve_mip(
-        self,
-        solver,
-        instance,
-        model,
-        stats,
-        features,
-        training_data,
-    ):
-        instance.found_violated_user_cuts = []
-        logger.info("Predicting violated user cuts...")
-        violations = self.predict(instance)
-        logger.info("Enforcing %d user cuts..." % len(violations))
-        for v in violations:
-            cut = instance.build_user_cut(model, v)
-            solver.internal_solver.add_constraint(cut)
-
-    def fit(self, training_instances):
-        logger.debug("Fitting...")
-        features = InstanceFeaturesExtractor().extract(training_instances)
-
-        self.classifiers = {}
-        violation_to_instance_idx = {}
-        for (idx, instance) in enumerate(training_instances):
-            if not hasattr(instance, "found_violated_user_cuts"):
-                continue
-            for v in instance.found_violated_user_cuts:
-                if v not in self.classifiers:
-                    self.classifiers[v] = self.classifier_prototype.clone()
-                    violation_to_instance_idx[v] = []
-                violation_to_instance_idx[v] += [idx]
-
-        for (v, classifier) in tqdm(
-            self.classifiers.items(),
-            desc="Fit (user cuts)",
-            disable=not sys.stdout.isatty(),
-        ):
-            logger.debug("Training: %s" % (str(v)))
-            label = np.zeros(len(training_instances))
-            label[violation_to_instance_idx[v]] = 1.0
-            classifier.fit(features, label)
-
-    def predict(self, instance):
-        violations = []
-        features = InstanceFeaturesExtractor().extract([instance])
-        for (v, classifier) in self.classifiers.items():
-            proba = classifier.predict_proba(features)
-            if proba[0][1] > self.threshold:
-                violations += [v]
-        return violations
-
-    def evaluate(self, instances):
-        results = {}
-        all_violations = set()
-        for instance in instances:
-            all_violations |= set(instance.found_violated_user_cuts)
-        for idx in tqdm(
-            range(len(instances)),
-            desc="Evaluate (lazy)",
-            disable=not sys.stdout.isatty(),
-        ):
-            instance = instances[idx]
-            condition_positive = set(instance.found_violated_user_cuts)
-            condition_negative = all_violations - condition_positive
-            pred_positive = set(self.predict(instance)) & all_violations
-            pred_negative = all_violations - pred_positive
-            tp = len(pred_positive & condition_positive)
-            tn = len(pred_negative & condition_negative)
-            fp = len(pred_positive & condition_negative)
-            fn = len(pred_negative & condition_positive)
-            results[idx] = classifier_evaluation_dict(tp, tn, fp, fn)
-        return results
diff --git a/miplearn/components/lazy_dynamic.py b/miplearn/components/dynamic_common.py
similarity index 68%
rename from miplearn/components/lazy_dynamic.py
rename to miplearn/components/dynamic_common.py
index 0de3c47..4d5f1e0 100644
--- a/miplearn/components/lazy_dynamic.py
+++ b/miplearn/components/dynamic_common.py
@@ -1,34 +1,27 @@
-#  MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
-#  Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved.
-#  Released under the modified BSD license. See COPYING.md for more details.
-
-import logging
-from typing import Dict, List, TYPE_CHECKING, Hashable, Tuple
+from typing import Dict, Hashable, List, Tuple, TYPE_CHECKING
 
 import numpy as np
 
 from miplearn.classifiers import Classifier
-from miplearn.classifiers.counting import CountingClassifier
-from miplearn.classifiers.threshold import MinProbabilityThreshold, Threshold
+from miplearn.classifiers.threshold import Threshold
 from miplearn.components import classifier_evaluation_dict
 from miplearn.components.component import Component
 from miplearn.features import TrainingSample
 
-logger = logging.getLogger(__name__)
-
 if TYPE_CHECKING:
     from miplearn.solvers.learning import Instance
 
 
-class DynamicLazyConstraintsComponent(Component):
+class DynamicConstraintsComponent(Component):
     """
-    A component that predicts which lazy constraints to enforce.
+    Base component used by both DynamicLazyConstraintsComponent and UserCutsComponent.
     """
 
     def __init__(
         self,
-        classifier: Classifier = CountingClassifier(),
-        threshold: Threshold = MinProbabilityThreshold([0, 0.05]),
+        attr: str,
+        classifier: Classifier,
+        threshold: Threshold,
     ):
         assert isinstance(classifier, Classifier)
         self.threshold_prototype: Threshold = threshold
@@ -36,39 +29,7 @@ class DynamicLazyConstraintsComponent(Component):
         self.classifiers: Dict[Hashable, Classifier] = {}
         self.thresholds: Dict[Hashable, Threshold] = {}
         self.known_cids: List[str] = []
-
-    @staticmethod
-    def enforce(cids, instance, model, solver):
-        for cid in cids:
-            cobj = instance.build_lazy_constraint(model, cid)
-            solver.internal_solver.add_constraint(cobj)
-
-    def before_solve_mip(
-        self,
-        solver,
-        instance,
-        model,
-        stats,
-        features,
-        training_data,
-    ):
-        training_data.lazy_enforced = set()
-        logger.info("Predicting violated lazy constraints...")
-        cids = self.sample_predict(instance, training_data)
-        logger.info("Enforcing %d lazy constraints..." % len(cids))
-        self.enforce(cids, instance, model, solver)
-
-    def iteration_cb(self, solver, instance, model):
-        logger.debug("Finding violated lazy constraints...")
-        cids = instance.find_violated_lazy_constraints(model)
-        if len(cids) == 0:
-            logger.debug("No violations found")
-            return False
-        else:
-            instance.training_data[-1].lazy_enforced |= set(cids)
-            logger.debug("    %d violations found" % len(cids))
-            self.enforce(cids, instance, model, solver)
-            return True
+        self.attr = attr
 
     def sample_xy_with_cids(
         self,
@@ -101,8 +62,8 @@ class DynamicLazyConstraintsComponent(Component):
             f += cfeatures
             x[category] += [f]
             cids[category] += [cid]
-            if sample.lazy_enforced is not None:
-                if cid in sample.lazy_enforced:
+            if getattr(sample, self.attr) is not None:
+                if cid in getattr(sample, self.attr):
                     y[category] += [[False, True]]
                 else:
                     y[category] += [[True, False]]
@@ -137,13 +98,14 @@ class DynamicLazyConstraintsComponent(Component):
         return pred
 
     def fit(self, training_instances: List["Instance"]) -> None:
-        self.known_cids.clear()
+        collected_cids = set()
         for instance in training_instances:
             for sample in instance.training_data:
-                if sample.lazy_enforced is None:
+                if getattr(sample, self.attr) is None:
                     continue
-                self.known_cids += list(sample.lazy_enforced)
-        self.known_cids = sorted(set(self.known_cids))
+                collected_cids |= getattr(sample, self.attr)
+        self.known_cids.clear()
+        self.known_cids.extend(sorted(collected_cids))
         super().fit(training_instances)
 
     def fit_xy(
@@ -164,7 +126,7 @@ class DynamicLazyConstraintsComponent(Component):
         instance: "Instance",
         sample: TrainingSample,
     ) -> Dict[Hashable, Dict[str, float]]:
-        assert sample.lazy_enforced is not None
+        assert getattr(sample, self.attr) is not None
         pred = set(self.sample_predict(instance, sample))
         tp: Dict[Hashable, int] = {}
         tn: Dict[Hashable, int] = {}
@@ -180,12 +142,12 @@ class DynamicLazyConstraintsComponent(Component):
                 fp[category] = 0
                 fn[category] = 0
             if cid in pred:
-                if cid in sample.lazy_enforced:
+                if cid in getattr(sample, self.attr):
                     tp[category] += 1
                 else:
                     fp[category] += 1
             else:
-                if cid in sample.lazy_enforced:
+                if cid in getattr(sample, self.attr):
                     fn[category] += 1
                 else:
                     tn[category] += 1
diff --git a/miplearn/components/dynamic_lazy.py b/miplearn/components/dynamic_lazy.py
new file mode 100644
index 0000000..2a5d6f9
--- /dev/null
+++ b/miplearn/components/dynamic_lazy.py
@@ -0,0 +1,106 @@
+#  MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
+#  Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved.
+#  Released under the modified BSD license. See COPYING.md for more details.
+
+import logging
+from typing import Dict, List, TYPE_CHECKING, Hashable, Tuple
+
+import numpy as np
+
+from miplearn.classifiers import Classifier
+from miplearn.classifiers.counting import CountingClassifier
+from miplearn.classifiers.threshold import MinProbabilityThreshold, Threshold
+from miplearn.components.component import Component
+from miplearn.components.dynamic_common import DynamicConstraintsComponent
+from miplearn.features import TrainingSample
+
+logger = logging.getLogger(__name__)
+
+if TYPE_CHECKING:
+    from miplearn.solvers.learning import Instance
+
+
+class DynamicLazyConstraintsComponent(Component):
+    """
+    A component that predicts which lazy constraints to enforce.
+    """
+
+    def __init__(
+        self,
+        classifier: Classifier = CountingClassifier(),
+        threshold: Threshold = MinProbabilityThreshold([0, 0.05]),
+    ):
+        self.dynamic: DynamicConstraintsComponent = DynamicConstraintsComponent(
+            classifier=classifier,
+            threshold=threshold,
+            attr="lazy_enforced",
+        )
+        self.classifiers = self.dynamic.classifiers
+        self.thresholds = self.dynamic.thresholds
+        self.known_cids = self.dynamic.known_cids
+
+    @staticmethod
+    def enforce(cids, instance, model, solver):
+        for cid in cids:
+            cobj = instance.build_lazy_constraint(model, cid)
+            solver.internal_solver.add_constraint(cobj)
+
+    def before_solve_mip(
+        self,
+        solver,
+        instance,
+        model,
+        stats,
+        features,
+        training_data,
+    ):
+        training_data.lazy_enforced = set()
+        logger.info("Predicting violated lazy constraints...")
+        cids = self.dynamic.sample_predict(instance, training_data)
+        logger.info("Enforcing %d lazy constraints..." % len(cids))
+        self.enforce(cids, instance, model, solver)
+
+    def iteration_cb(self, solver, instance, model):
+        logger.debug("Finding violated lazy constraints...")
+        cids = instance.find_violated_lazy_constraints(model)
+        if len(cids) == 0:
+            logger.debug("No violations found")
+            return False
+        else:
+            instance.training_data[-1].lazy_enforced |= set(cids)
+            logger.debug("    %d violations found" % len(cids))
+            self.enforce(cids, instance, model, solver)
+            return True
+
+    # Delegate ML methods to self.dynamic
+    # -------------------------------------------------------------------
+    def sample_xy(
+        self,
+        instance: "Instance",
+        sample: TrainingSample,
+    ) -> Tuple[Dict, Dict]:
+        return self.dynamic.sample_xy(instance, sample)
+
+    def sample_predict(
+        self,
+        instance: "Instance",
+        sample: TrainingSample,
+    ) -> List[str]:
+        return self.dynamic.sample_predict(instance, sample)
+
+    def fit(self, training_instances: List["Instance"]) -> None:
+        self.dynamic.fit(training_instances)
+
+    def fit_xy(
+        self,
+        x: Dict[Hashable, np.ndarray],
+        y: Dict[Hashable, np.ndarray],
+    ) -> None:
+        self.dynamic.fit_xy(x, y)
+
+    def sample_evaluate(
+        self,
+        instance: "Instance",
+        sample: TrainingSample,
+    ) -> Dict[Hashable, Dict[str, float]]:
+        return self.dynamic.sample_evaluate(instance, sample)
diff --git a/miplearn/components/dynamic_user_cuts.py b/miplearn/components/dynamic_user_cuts.py
new file mode 100644
index 0000000..c792a01
--- /dev/null
+++ b/miplearn/components/dynamic_user_cuts.py
@@ -0,0 +1,125 @@
+#  MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
+#  Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved.
+#  Released under the modified BSD license. See COPYING.md for more details.
+
+import logging
+from typing import Any, TYPE_CHECKING, Hashable, Set, Tuple, Dict, List
+
+import numpy as np
+
+from miplearn.classifiers import Classifier
+from miplearn.classifiers.counting import CountingClassifier
+from miplearn.classifiers.threshold import Threshold, MinProbabilityThreshold
+from miplearn.components.component import Component
+from miplearn.components.dynamic_common import DynamicConstraintsComponent
+from miplearn.features import Features, TrainingSample
+from miplearn.types import LearningSolveStats
+
+logger = logging.getLogger(__name__)
+
+if TYPE_CHECKING:
+    from miplearn.solvers.learning import LearningSolver, Instance
+
+
+class UserCutsComponent(Component):
+    def __init__(
+        self,
+        classifier: Classifier = CountingClassifier(),
+        threshold: Threshold = MinProbabilityThreshold([0.50, 0.50]),
+    ) -> None:
+        self.dynamic = DynamicConstraintsComponent(
+            classifier=classifier,
+            threshold=threshold,
+            attr="user_cuts_enforced",
+        )
+        self.enforced: Set[Hashable] = set()
+        self.n_added_in_callback = 0
+
+    def before_solve_mip(
+        self,
+        solver: "LearningSolver",
+        instance: "Instance",
+        model: Any,
+        stats: LearningSolveStats,
+        features: Features,
+        training_data: TrainingSample,
+    ) -> None:
+        assert solver.internal_solver is not None
+        self.enforced.clear()
+        self.n_added_in_callback = 0
+        logger.info("Predicting violated user cuts...")
+        cids = self.dynamic.sample_predict(instance, training_data)
+        logger.info("Enforcing %d user cuts ahead-of-time..." % len(cids))
+        for cid in cids:
+            cobj = instance.build_user_cut(model, cid)
+            solver.internal_solver.add_constraint(cobj)
+        stats["UserCuts: Added ahead-of-time"] = len(cids)
+
+    def user_cut_cb(
+        self,
+        solver: "LearningSolver",
+        instance: "Instance",
+        model: Any,
+    ) -> None:
+        assert solver.internal_solver is not None
+        logger.debug("Finding violated user cuts...")
+        cids = instance.find_violated_user_cuts(model)
+        logger.debug(f"Found {len(cids)} violated user cuts")
+        logger.debug("Building violated user cuts...")
+        for cid in cids:
+            if cid in self.enforced:
+                continue
+            assert isinstance(cid, Hashable)
+            cobj = instance.build_user_cut(model, cid)
+            assert cobj is not None
+            solver.internal_solver.add_cut(cobj)
+            self.enforced.add(cid)
+            self.n_added_in_callback += 1
+        if len(cids) > 0:
+            logger.debug(f"Added {len(cids)} violated user cuts")
+
+    def after_solve_mip(
+        self,
+        solver: "LearningSolver",
+        instance: "Instance",
+        model: Any,
+        stats: LearningSolveStats,
+        features: Features,
+        training_data: TrainingSample,
+    ) -> None:
+        training_data.user_cuts_enforced = set(self.enforced)
+        stats["UserCuts: Added in callback"] = self.n_added_in_callback
+        logger.info(f"{self.n_added_in_callback} user cuts added in callback")
+
+    # Delegate ML methods to self.dynamic
+    # -------------------------------------------------------------------
+    def sample_xy(
+        self,
+        instance: "Instance",
+        sample: TrainingSample,
+    ) -> Tuple[Dict, Dict]:
+        return self.dynamic.sample_xy(instance, sample)
+
+    def sample_predict(
+        self,
+        instance: "Instance",
+        sample: TrainingSample,
+    ) -> List[str]:
+        return self.dynamic.sample_predict(instance, sample)
+
+    def fit(self, training_instances: List["Instance"]) -> None:
+        self.dynamic.fit(training_instances)
+
+    def fit_xy(
+        self,
+        x: Dict[Hashable, np.ndarray],
+        y: Dict[Hashable, np.ndarray],
+    ) -> None:
+        self.dynamic.fit_xy(x, y)
+
+    def sample_evaluate(
+        self,
+        instance: "Instance",
+        sample: TrainingSample,
+    ) -> Dict[Hashable, Dict[str, float]]:
+        return self.dynamic.sample_evaluate(instance, sample)
diff --git a/miplearn/components/lazy_static.py b/miplearn/components/static_lazy.py
similarity index 99%
rename from miplearn/components/lazy_static.py
rename to miplearn/components/static_lazy.py
index c0cf04f..3d688a2 100644
--- a/miplearn/components/lazy_static.py
+++ b/miplearn/components/static_lazy.py
@@ -7,16 +7,15 @@ from typing import Dict, Tuple, List, Hashable, Any, TYPE_CHECKING, Set
 
 import numpy as np
 
-from miplearn import Classifier
+from miplearn.classifiers import Classifier
 from miplearn.classifiers.counting import CountingClassifier
 from miplearn.classifiers.threshold import MinProbabilityThreshold, Threshold
 from miplearn.components.component import Component
-from miplearn.types import LearningSolveStats
 from miplearn.features import TrainingSample, Features
+from miplearn.types import LearningSolveStats
 
 logger = logging.getLogger(__name__)
 
-
 if TYPE_CHECKING:
     from miplearn.solvers.learning import LearningSolver, Instance
 
diff --git a/miplearn/components/steps/drop_redundant.py b/miplearn/components/steps/drop_redundant.py
index ab435d7..e67e17c 100644
--- a/miplearn/components/steps/drop_redundant.py
+++ b/miplearn/components/steps/drop_redundant.py
@@ -12,7 +12,7 @@ from tqdm import tqdm
 from miplearn.classifiers.counting import CountingClassifier
 from miplearn.components import classifier_evaluation_dict
 from miplearn.components.component import Component
-from miplearn.components.lazy_static import LazyConstraint
+from miplearn.components.static_lazy import LazyConstraint
 
 logger = logging.getLogger(__name__)
 
diff --git a/miplearn/components/user_cuts.py b/miplearn/components/user_cuts.py
deleted file mode 100644
index 3790e3d..0000000
--- a/miplearn/components/user_cuts.py
+++ /dev/null
@@ -1,64 +0,0 @@
-#  MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
-#  Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved.
-#  Released under the modified BSD license. See COPYING.md for more details.
-
-from typing import Any, TYPE_CHECKING, Hashable, Set
-
-from miplearn import Component, Instance
-
-import logging
-
-from miplearn.features import Features, TrainingSample
-from miplearn.types import LearningSolveStats
-
-logger = logging.getLogger(__name__)
-
-if TYPE_CHECKING:
-    from miplearn.solvers.learning import LearningSolver
-
-
-class UserCutsComponentNG(Component):
-    def __init__(self) -> None:
-        self.enforced: Set[Hashable] = set()
-
-    def before_solve_mip(
-        self,
-        solver: "LearningSolver",
-        instance: Instance,
-        model: Any,
-        stats: LearningSolveStats,
-        features: Features,
-        training_data: TrainingSample,
-    ) -> None:
-        self.enforced.clear()
-
-    def after_solve_mip(
-        self,
-        solver: "LearningSolver",
-        instance: Instance,
-        model: Any,
-        stats: LearningSolveStats,
-        features: Features,
-        training_data: TrainingSample,
-    ) -> None:
-        training_data.user_cuts_enforced = set(self.enforced)
-
-    def user_cut_cb(
-        self,
-        solver: "LearningSolver",
-        instance: Instance,
-        model: Any,
-    ) -> None:
-        assert solver.internal_solver is not None
-        logger.debug("Finding violated user cuts...")
-        cids = instance.find_violated_user_cuts(model)
-        logger.debug(f"Found {len(cids)} violated user cuts")
-        logger.debug("Building violated user cuts...")
-        for cid in cids:
-            assert isinstance(cid, Hashable)
-            cobj = instance.build_user_cut(model, cid)
-            assert cobj is not None
-            solver.internal_solver.add_cut(cobj)
-            self.enforced.add(cid)
-        if len(cids) > 0:
-            logger.info(f"Added {len(cids)} violated user cuts")
diff --git a/miplearn/features.py b/miplearn/features.py
index f78ddb3..274b47e 100644
--- a/miplearn/features.py
+++ b/miplearn/features.py
@@ -10,7 +10,8 @@ from typing import TYPE_CHECKING, Dict, Optional, Set, List, Hashable
 from miplearn.types import VarIndex, Solution
 
 if TYPE_CHECKING:
-    from miplearn import InternalSolver, Instance
+    from miplearn.solvers.internal import InternalSolver
+    from miplearn.instance import Instance
 
 
 @dataclass
diff --git a/miplearn/solvers/learning.py b/miplearn/solvers/learning.py
index a005abc..80b8f7f 100644
--- a/miplearn/solvers/learning.py
+++ b/miplearn/solvers/learning.py
@@ -9,8 +9,8 @@ from typing import Optional, List, Any, cast, Callable, Dict
 from p_tqdm import p_map
 
 from miplearn.components.component import Component
-from miplearn.components.cuts import UserCutsComponent
-from miplearn.components.lazy_dynamic import DynamicLazyConstraintsComponent
+from miplearn.components.dynamic_lazy import DynamicLazyConstraintsComponent
+from miplearn.components.dynamic_user_cuts import UserCutsComponent
 from miplearn.components.objective import ObjectiveValueComponent
 from miplearn.components.primal import PrimalSolutionComponent
 from miplearn.features import FeaturesExtractor, TrainingSample
diff --git a/miplearn/types.py b/miplearn/types.py
index 688e520..6bbb789 100644
--- a/miplearn/types.py
+++ b/miplearn/types.py
@@ -59,6 +59,8 @@ LearningSolveStats = TypedDict(
         "LazyStatic: Kept": int,
         "LazyStatic: Restored": int,
         "LazyStatic: Iterations": int,
+        "UserCuts: Added ahead-of-time": int,
+        "UserCuts: Added in callback": int,
     },
     total=False,
 )
diff --git a/tests/classifiers/test_adaptive.py b/tests/classifiers/test_adaptive.py
index f362507..1074ba7 100644
--- a/tests/classifiers/test_adaptive.py
+++ b/tests/classifiers/test_adaptive.py
@@ -5,8 +5,8 @@
 from numpy.linalg import norm
 from sklearn.svm import SVC
 
-from miplearn import AdaptiveClassifier, ScikitLearnClassifier
-from miplearn.classifiers.adaptive import CandidateClassifierSpecs
+from miplearn.classifiers.adaptive import CandidateClassifierSpecs, AdaptiveClassifier
+from miplearn.classifiers.sklearn import ScikitLearnClassifier
 from tests.classifiers import _build_circle_training_data
 
 
diff --git a/tests/components/steps/test_drop_redundant.py b/tests/components/steps/test_drop_redundant.py
index 2efe548..aaec305 100644
--- a/tests/components/steps/test_drop_redundant.py
+++ b/tests/components/steps/test_drop_redundant.py
@@ -6,10 +6,11 @@ from unittest.mock import Mock, call
 
 import numpy as np
 
-from miplearn import RelaxIntegralityStep, GurobiSolver
 from miplearn.classifiers import Classifier
 from miplearn.components.steps.drop_redundant import DropRedundantInequalitiesStep
+from miplearn.components.steps.relax_integrality import RelaxIntegralityStep
 from miplearn.instance import Instance
+from miplearn.solvers.gurobi import GurobiSolver
 from miplearn.solvers.internal import InternalSolver
 from miplearn.solvers.learning import LearningSolver
 from miplearn.features import TrainingSample, Features
diff --git a/tests/components/test_component.py b/tests/components/test_component.py
index 2d6bcf9..01eb931 100644
--- a/tests/components/test_component.py
+++ b/tests/components/test_component.py
@@ -3,7 +3,8 @@
 #  Released under the modified BSD license. See COPYING.md for more details.
 from unittest.mock import Mock
 
-from miplearn import Component, Instance
+from miplearn.components.component import Component
+from miplearn.instance import Instance
 
 
 def test_xy_instance():
diff --git a/tests/components/test_lazy_dynamic.py b/tests/components/test_dynamic_lazy.py
similarity index 97%
rename from tests/components/test_lazy_dynamic.py
rename to tests/components/test_dynamic_lazy.py
index cb2f82c..7144a5f 100644
--- a/tests/components/test_lazy_dynamic.py
+++ b/tests/components/test_dynamic_lazy.py
@@ -8,16 +8,16 @@ import numpy as np
 import pytest
 from numpy.testing import assert_array_equal
 
-from miplearn import Instance
 from miplearn.classifiers import Classifier
 from miplearn.classifiers.threshold import MinProbabilityThreshold
 from miplearn.components import classifier_evaluation_dict
-from miplearn.components.lazy_dynamic import DynamicLazyConstraintsComponent
+from miplearn.components.dynamic_lazy import DynamicLazyConstraintsComponent
 from miplearn.features import (
     TrainingSample,
     Features,
     InstanceFeatures,
 )
+from miplearn.instance import Instance
 
 E = 0.1
 
@@ -144,7 +144,7 @@ def test_fit(training_instances: List[Instance]) -> None:
 
 def test_sample_predict_evaluate(training_instances: List[Instance]) -> None:
     comp = DynamicLazyConstraintsComponent()
-    comp.known_cids = ["c1", "c2", "c3", "c4"]
+    comp.known_cids.extend(["c1", "c2", "c3", "c4"])
     comp.thresholds["type-a"] = MinProbabilityThreshold([0.5, 0.5])
     comp.thresholds["type-b"] = MinProbabilityThreshold([0.5, 0.5])
     comp.classifiers["type-a"] = Mock(spec=Classifier)
diff --git a/tests/components/test_user_cuts.py b/tests/components/test_dynamic_user_cuts.py
similarity index 66%
rename from tests/components/test_user_cuts.py
rename to tests/components/test_dynamic_user_cuts.py
index cbd6084..0f26cc9 100644
--- a/tests/components/test_user_cuts.py
+++ b/tests/components/test_dynamic_user_cuts.py
@@ -11,8 +11,10 @@ import pytest
 from gurobipy import GRB
 from networkx import Graph
 
-from miplearn import Instance, LearningSolver, GurobiSolver
-from miplearn.components.user_cuts import UserCutsComponentNG
+from miplearn.components.dynamic_user_cuts import UserCutsComponent
+from miplearn.instance import Instance
+from miplearn.solvers.gurobi import GurobiSolver
+from miplearn.solvers.learning import LearningSolver
 
 logger = logging.getLogger(__name__)
 
@@ -20,12 +22,11 @@ logger = logging.getLogger(__name__)
 class GurobiStableSetProblem(Instance):
     def __init__(self, graph: Graph) -> None:
         super().__init__()
-        self.graph = graph
-        self.nodes = list(self.graph.nodes)
+        self.graph: Graph = graph
 
     def to_model(self) -> Any:
         model = gp.Model()
-        x = [model.addVar(vtype=GRB.BINARY) for _ in range(len(self.nodes))]
+        x = [model.addVar(vtype=GRB.BINARY) for _ in range(len(self.graph.nodes))]
         model.setObjective(gp.quicksum(x), GRB.MAXIMIZE)
         for e in list(self.graph.edges):
             model.addConstr(x[e[0]] + x[e[1]] <= 1)
@@ -39,16 +40,14 @@ class GurobiStableSetProblem(Instance):
         vals = model.cbGetNodeRel(model.getVars())
         violations = []
         for clique in nx.find_cliques(self.graph):
-            lhs = sum(vals[i] for i in clique)
-            if lhs > 1:
+            if sum(vals[i] for i in clique) > 1:
                 violations += [frozenset(clique)]
         return violations
 
-    def build_user_cut(self, model: Any, violation: Hashable) -> Any:
-        assert isinstance(violation, FrozenSet)
+    def build_user_cut(self, model: Any, cid: Hashable) -> Any:
+        assert isinstance(cid, FrozenSet)
         x = model.getVars()
-        cut = gp.quicksum([x[i] for i in violation]) <= 1
-        return cut
+        return gp.quicksum([x[i] for i in cid]) <= 1
 
 
 @pytest.fixture
@@ -62,7 +61,7 @@ def solver() -> LearningSolver:
     return LearningSolver(
         solver=lambda: GurobiSolver(),
         components=[
-            UserCutsComponentNG(),
+            UserCutsComponent(),
         ],
     )
 
@@ -71,7 +70,17 @@ def test_usage(
     stab_instance: Instance,
     solver: LearningSolver,
 ) -> None:
-    solver.solve(stab_instance)
+    stats_before = solver.solve(stab_instance)
     sample = stab_instance.training_data[0]
     assert sample.user_cuts_enforced is not None
     assert len(sample.user_cuts_enforced) > 0
+    print(stats_before)
+    assert stats_before["UserCuts: Added ahead-of-time"] == 0
+    assert stats_before["UserCuts: Added in callback"] > 0
+
+    solver.fit([stab_instance])
+    stats_after = solver.solve(stab_instance)
+    assert (
+        stats_after["UserCuts: Added ahead-of-time"]
+        == stats_before["UserCuts: Added in callback"]
+    )
diff --git a/tests/components/test_objective.py b/tests/components/test_objective.py
index 24ee154..e3dbcd3 100644
--- a/tests/components/test_objective.py
+++ b/tests/components/test_objective.py
@@ -7,9 +7,12 @@ from unittest.mock import Mock
 import pytest
 from numpy.testing import assert_array_equal
 
-from miplearn import GurobiPyomoSolver, LearningSolver, Regressor, Instance
+from miplearn.classifiers import Regressor
 from miplearn.components.objective import ObjectiveValueComponent
 from miplearn.features import TrainingSample, InstanceFeatures, Features
+from miplearn.instance import Instance
+from miplearn.solvers.learning import LearningSolver
+from miplearn.solvers.pyomo.gurobi import GurobiPyomoSolver
 from tests.fixtures.knapsack import get_knapsack_instance
 
 import numpy as np
diff --git a/tests/components/test_primal.py b/tests/components/test_primal.py
index 1279135..7ab4766 100644
--- a/tests/components/test_primal.py
+++ b/tests/components/test_primal.py
@@ -8,12 +8,14 @@ import numpy as np
 from numpy.testing import assert_array_equal
 from scipy.stats import randint
 
-from miplearn import Classifier, LearningSolver, Instance
+from miplearn.classifiers import Classifier
 from miplearn.classifiers.threshold import Threshold
 from miplearn.components import classifier_evaluation_dict
 from miplearn.components.primal import PrimalSolutionComponent
+from miplearn.instance import Instance
 from miplearn.problems.tsp import TravelingSalesmanGenerator
 from miplearn.features import TrainingSample, VariableFeatures, Features
+from miplearn.solvers.learning import LearningSolver
 
 
 def test_xy() -> None:
diff --git a/tests/components/test_lazy_static.py b/tests/components/test_static_lazy.py
similarity index 97%
rename from tests/components/test_lazy_static.py
rename to tests/components/test_static_lazy.py
index 4d62b5c..bf1f442 100644
--- a/tests/components/test_lazy_static.py
+++ b/tests/components/test_static_lazy.py
@@ -8,10 +8,12 @@ import numpy as np
 import pytest
 from numpy.testing import assert_array_equal
 
-from miplearn import LearningSolver, InternalSolver, Instance
 from miplearn.classifiers import Classifier
 from miplearn.classifiers.threshold import Threshold, MinProbabilityThreshold
-from miplearn.components.lazy_static import StaticLazyConstraintsComponent
+from miplearn.components.static_lazy import StaticLazyConstraintsComponent
+from miplearn.instance import Instance
+from miplearn.solvers.internal import InternalSolver
+from miplearn.solvers.learning import LearningSolver
 from miplearn.types import (
     LearningSolveStats,
 )
diff --git a/tests/fixtures/knapsack.py b/tests/fixtures/knapsack.py
index 14e25ce..8d649ff 100644
--- a/tests/fixtures/knapsack.py
+++ b/tests/fixtures/knapsack.py
@@ -1,10 +1,12 @@
 #  MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
 #  Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved.
 #  Released under the modified BSD license. See COPYING.md for more details.
-
-from miplearn import BasePyomoSolver, GurobiSolver, InternalSolver, Instance
+from miplearn.instance import Instance
 from miplearn.problems.knapsack import KnapsackInstance, GurobiKnapsackInstance
+from miplearn.solvers.gurobi import GurobiSolver
+from miplearn.solvers.internal import InternalSolver
 from miplearn.solvers.learning import LearningSolver
+from miplearn.solvers.pyomo.base import BasePyomoSolver
 from tests.solvers import _is_subclass_or_instance
 
 
diff --git a/tests/fixtures/redundant.py b/tests/fixtures/redundant.py
index a9e9ae6..3dd5107 100644
--- a/tests/fixtures/redundant.py
+++ b/tests/fixtures/redundant.py
@@ -3,9 +3,11 @@
 #  Released under the modified BSD license. See COPYING.md for more details.
 from typing import Any
 
-from miplearn import Instance, BasePyomoSolver, GurobiSolver
 import pyomo.environ as pe
 
+from miplearn.instance import Instance
+from miplearn.solvers.gurobi import GurobiSolver
+from miplearn.solvers.pyomo.base import BasePyomoSolver
 from tests.solvers import _is_subclass_or_instance
 
 
diff --git a/tests/problems/test_tsp.py b/tests/problems/test_tsp.py
index 908f560..88bed41 100644
--- a/tests/problems/test_tsp.py
+++ b/tests/problems/test_tsp.py
@@ -67,7 +67,6 @@ def test_subtour():
     solver = LearningSolver()
     solver.solve(instance)
     assert len(instance.training_data[0].lazy_enforced) > 0
-    assert hasattr(instance, "found_violated_user_cuts")
     x = instance.training_data[0].solution["x"]
     assert x[0, 1] == 1.0
     assert x[0, 4] == 1.0
diff --git a/tests/test_benchmark.py b/tests/test_benchmark.py
index 0baca38..b33d695 100644
--- a/tests/test_benchmark.py
+++ b/tests/test_benchmark.py
@@ -30,7 +30,7 @@ def test_benchmark():
         benchmark = BenchmarkRunner(test_solvers)
         benchmark.fit(train_instances)
         benchmark.parallel_solve(test_instances, n_jobs=n_jobs, n_trials=2)
-        assert benchmark.results.values.shape == (12, 18)
+        assert benchmark.results.values.shape == (12, 20)
 
         benchmark.write_csv("/tmp/benchmark.csv")
         assert os.path.isfile("/tmp/benchmark.csv")
diff --git a/tests/test_features.py b/tests/test_features.py
index b4e964f..43dbae6 100644
--- a/tests/test_features.py
+++ b/tests/test_features.py
@@ -2,13 +2,13 @@
 #  Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved.
 #  Released under the modified BSD license. See COPYING.md for more details.
 
-from miplearn import GurobiSolver
 from miplearn.features import (
     FeaturesExtractor,
     InstanceFeatures,
     VariableFeatures,
     ConstraintFeatures,
 )
+from miplearn.solvers.gurobi import GurobiSolver
 from tests.fixtures.knapsack import get_knapsack_instance
 
 
diff --git a/tests/test_instance.py b/tests/test_instance.py
index 0ee3b9c..c76b0ad 100644
--- a/tests/test_instance.py
+++ b/tests/test_instance.py
@@ -3,8 +3,8 @@
 #  Released under the modified BSD license. See COPYING.md for more details.
 import tempfile
 
-from miplearn import GurobiSolver
 from miplearn.instance import write_pickle_gz, PickleGzInstance
+from miplearn.solvers.gurobi import GurobiSolver
 from tests.fixtures.knapsack import get_knapsack_instance