diff --git a/tests/core/pyspec/eth2spec/config/config_util.py b/tests/core/pyspec/eth2spec/config/config_util.py
index 3f6764e98..ee2007600 100644
--- a/tests/core/pyspec/eth2spec/config/config_util.py
+++ b/tests/core/pyspec/eth2spec/config/config_util.py
@@ -17,8 +17,8 @@ def apply_constants_config(spec_globals: Dict[str, Any], warn_if_unknown: bool =
             # Keep the same type as the default value indicates (which may be an SSZ basic type subclass, e.g. 'Gwei')
             spec_globals[k] = spec_globals[k].__class__(v)
         else:
-            # Note: Phase 0 spec will not know the phase 1 config values.
-            # Yet, during debugging you can enable explicit warnings.
+            # Note: The phase 0 spec will not warn if Altair or later config values are applied.
+            # During debugging you can enable explicit warnings.
             if warn_if_unknown:
                 print(f"WARNING: unknown config key: '{k}' with value: '{v}'")
 
diff --git a/tests/core/pyspec/eth2spec/test/helpers/state.py b/tests/core/pyspec/eth2spec/test/helpers/state.py
index f53d8f711..8980053f5 100644
--- a/tests/core/pyspec/eth2spec/test/helpers/state.py
+++ b/tests/core/pyspec/eth2spec/test/helpers/state.py
@@ -42,9 +42,9 @@ def transition_to_slot_via_block(spec, state, slot):
 
 def transition_to_valid_shard_slot(spec, state):
     """
-    Transition to slot `spec.PHASE_1_FORK_SLOT + 1` and fork at `spec.PHASE_1_FORK_SLOT`.
+    Transition to slot `spec.SHARDING_FORK_SLOT + 1` and fork at `spec.SHARDING_FORK_SLOT`.
     """
-    transition_to(spec, state, spec.PHASE_1_FORK_SLOT)
+    transition_to(spec, state, spec.SHARDING_FORK_SLOT)
     next_slot(spec, state)
 
 
diff --git a/tests/core/pyspec/eth2spec/test/phase0/epoch_processing/test_process_rewards_and_penalties.py b/tests/core/pyspec/eth2spec/test/phase0/epoch_processing/test_process_rewards_and_penalties.py
index cebe65e03..9abcff57e 100644
--- a/tests/core/pyspec/eth2spec/test/phase0/epoch_processing/test_process_rewards_and_penalties.py
+++ b/tests/core/pyspec/eth2spec/test/phase0/epoch_processing/test_process_rewards_and_penalties.py
@@ -292,8 +292,6 @@ def test_duplicate_attestation(spec, state):
         assert single_state.balances[index] == dup_state.balances[index]
 
 
-# TODO: update to all phases when https://github.com/ethereum/eth2.0-specs/pull/2024 is merged
-# Currently disabled for Phase 1+ due to the mechanics of on-time-attestations complicating what should be a simple test
 @with_phases([PHASE0])
 @spec_state_test
 def test_duplicate_participants_different_attestation_1(spec, state):
@@ -334,8 +332,6 @@ def test_duplicate_participants_different_attestation_1(spec, state):
         assert single_correct_state.balances[index] == dup_state.balances[index]
 
 
-# TODO: update to all phases when https://github.com/ethereum/eth2.0-specs/pull/2024 is merged
-# Currently disabled for Phase 1+ due to the mechanics of on-time-attestations complicating what should be a simple test
 @with_phases([PHASE0])
 @spec_state_test
 def test_duplicate_participants_different_attestation_2(spec, state):
@@ -377,8 +373,6 @@ def test_duplicate_participants_different_attestation_2(spec, state):
         assert single_correct_state.balances[index] == dup_state.balances[index]
 
 
-# TODO: update to all phases when https://github.com/ethereum/eth2.0-specs/pull/2024 is merged
-# Currently disabled for Phase 1+ due to the mechanics of on-time-attestations complicating what should be a simple test
 @with_phases([PHASE0])
 @spec_state_test
 def test_duplicate_participants_different_attestation_3(spec, state):
diff --git a/tests/formats/README.md b/tests/formats/README.md
index 7808538ad..8f817220e 100644
--- a/tests/formats/README.md
+++ b/tests/formats/README.md
@@ -108,8 +108,8 @@ As a top level dir, it is not duplicated, and the used config can be copied righ
 
 ### `<fork or phase name>/`
 
-This would be: "phase0", "transferparty", "phase1", etc. Each introduces new tests, but does not copy tests that do not change. 
-If you like to test phase 1, you run phase 0 tests, with the configuration that includes phase 1 changes. Out of scope for now however.
+This would be: "phase0", "altair", etc. Each introduces new tests, and modifies any tests that change:
+some tests of earlier forks repeat with updated state data.
 
 ### `<test runner name>/`
 
diff --git a/tests/generators/README.md b/tests/generators/README.md
index f629c8b74..5e12e6bfe 100644
--- a/tests/generators/README.md
+++ b/tests/generators/README.md
@@ -164,13 +164,12 @@ Another example, to generate tests from pytests:
 ```python
 from eth2spec.phase0 import spec as spec_phase0
 from eth2spec.altair import spec as spec_altair
-from eth2spec.phase1 import spec as spec_phase1
-from eth2spec.test.context import PHASE0, PHASE1, ALTAIR
+from eth2spec.test.context import PHASE0, ALTAIR
 
 from eth2spec.gen_helpers.gen_from_tests.gen import run_state_test_generators
 
 
-specs = (spec_phase0, spec_altair, spec_phase1)
+specs = (spec_phase0, spec_altair)
 
 
 if __name__ == "__main__":
@@ -181,15 +180,10 @@ if __name__ == "__main__":
     altair_mods = {**{key: 'eth2spec.test.altair.sanity.test_' + key for key in [
         'blocks',
     ]}, **phase_0_mods}  # also run the previous phase 0 tests
-    phase_1_mods = {**{key: 'eth2spec.test.phase1.sanity.test_' + key for key in [
-        'blocks',  # more phase 1 specific block tests
-        'shard_blocks',
-    ]}, **phase_0_mods}  # also run the previous phase 0 tests (but against phase 1 spec)
 
     all_mods = {
         PHASE0: phase_0_mods,
         ALTAIR: altair_mods,
-        PHASE1: phase_1_mods,
     }
 
     run_state_test_generators(runner_name="sanity", specs=specs, all_mods=all_mods)
diff --git a/tests/generators/epoch_processing/main.py b/tests/generators/epoch_processing/main.py
index 5207330a7..e3caf69fa 100644
--- a/tests/generators/epoch_processing/main.py
+++ b/tests/generators/epoch_processing/main.py
@@ -1,11 +1,10 @@
 from eth2spec.gen_helpers.gen_from_tests.gen import run_state_test_generators
 from eth2spec.phase0 import spec as spec_phase0
 from eth2spec.altair import spec as spec_altair
-from eth2spec.phase1 import spec as spec_phase1
-from eth2spec.test.context import PHASE0, PHASE1, ALTAIR
+from eth2spec.test.context import PHASE0, ALTAIR
 
 
-specs = (spec_phase0, spec_altair, spec_phase1)
+specs = (spec_phase0, spec_altair)
 
 
 if __name__ == "__main__":
@@ -27,16 +26,17 @@ if __name__ == "__main__":
         ]},
         **phase_0_mods,
     }  # also run the previous phase 0 tests
-    phase_1_mods = {**{key: 'eth2spec.test.phase1.epoch_processing.test_process_' + key for key in [
-        'reveal_deadlines',
-        'challenge_deadlines',
-        'custody_final_updates',
-    ]}, **phase_0_mods}  # also run the previous phase 0 tests (but against phase 1 spec)
+
+    # TODO Custody Game testgen is disabled for now
+    # custody_game_mods = {**{key: 'eth2spec.test.custody_game.epoch_processing.test_process_' + key for key in [
+    #     'reveal_deadlines',
+    #     'challenge_deadlines',
+    #     'custody_final_updates',
+    # ]}, **phase_0_mods}  # also run the previous phase 0 tests (but against custody game spec)
 
     all_mods = {
         PHASE0: phase_0_mods,
         ALTAIR: altair_mods,
-        PHASE1: phase_1_mods,
     }
 
     run_state_test_generators(runner_name="epoch_processing", specs=specs, all_mods=all_mods)
diff --git a/tests/generators/finality/main.py b/tests/generators/finality/main.py
index 5598028a2..29ab46c39 100644
--- a/tests/generators/finality/main.py
+++ b/tests/generators/finality/main.py
@@ -1,23 +1,19 @@
 from eth2spec.gen_helpers.gen_from_tests.gen import run_state_test_generators
 from eth2spec.phase0 import spec as spec_phase0
 from eth2spec.altair import spec as spec_altair
-from eth2spec.phase1 import spec as spec_phase1
-from eth2spec.test.context import PHASE0, PHASE1, ALTAIR
+from eth2spec.test.context import PHASE0, ALTAIR
 
 
-specs = (spec_phase0, spec_altair, spec_phase1)
+specs = (spec_phase0, spec_altair)
 
 
 if __name__ == "__main__":
     phase_0_mods = {'finality': 'eth2spec.test.phase0.finality.test_finality'}
-    # No additional altair or phase 1 specific finality tests, yet.
-    altair_mods = phase_0_mods
-    phase_1_mods = phase_0_mods
+    altair_mods = phase_0_mods   # No additional altair specific finality tests
 
     all_mods = {
         PHASE0: phase_0_mods,
         ALTAIR: altair_mods,
-        PHASE1: phase_1_mods,
     }
 
     run_state_test_generators(runner_name="finality", specs=specs, all_mods=all_mods)
diff --git a/tests/generators/fork_choice/main.py b/tests/generators/fork_choice/main.py
index 492e596f4..f09bbcc0a 100644
--- a/tests/generators/fork_choice/main.py
+++ b/tests/generators/fork_choice/main.py
@@ -1,25 +1,22 @@
 from eth2spec.gen_helpers.gen_from_tests.gen import run_state_test_generators
 from eth2spec.phase0 import spec as spec_phase0
 from eth2spec.altair import spec as spec_altair
-from eth2spec.phase1 import spec as spec_phase1
-from eth2spec.test.context import PHASE0, PHASE1, ALTAIR
+from eth2spec.test.context import PHASE0, ALTAIR
 
 
-specs = (spec_phase0, spec_altair, spec_phase1)
+specs = (spec_phase0, spec_altair)
 
 
 if __name__ == "__main__":
     phase_0_mods = {key: 'eth2spec.test.phase0.fork_choice.test_' + key for key in [
         'get_head',
     ]}
-    # No additional Altair or phase 1 specific finality tests, yet.
+    # No additional Altair specific finality tests, yet.
     altair_mods = phase_0_mods
-    phase_1_mods = phase_0_mods
 
     all_mods = {
         PHASE0: phase_0_mods,
         ALTAIR: altair_mods,
-        PHASE1: phase_1_mods,
     }
 
     run_state_test_generators(runner_name="fork_choice", specs=specs, all_mods=all_mods)
diff --git a/tests/generators/genesis/main.py b/tests/generators/genesis/main.py
index 4fede298f..362677c24 100644
--- a/tests/generators/genesis/main.py
+++ b/tests/generators/genesis/main.py
@@ -1,11 +1,10 @@
 from eth2spec.gen_helpers.gen_from_tests.gen import run_state_test_generators
 from eth2spec.phase0 import spec as spec_phase0
 from eth2spec.altair import spec as spec_altair
-from eth2spec.phase1 import spec as spec_phase1
-from eth2spec.test.context import PHASE0, PHASE1, ALTAIR
+from eth2spec.test.context import PHASE0, ALTAIR
 
 
-specs = (spec_phase0, spec_altair, spec_phase1)
+specs = (spec_phase0, spec_altair)
 
 
 if __name__ == "__main__":
@@ -14,11 +13,9 @@ if __name__ == "__main__":
         'validity',
     ]}
     altair_mods = phase_0_mods
-    phase_1_mods = phase_0_mods
     all_mods = {
         PHASE0: phase_0_mods,
         ALTAIR: altair_mods,
-        PHASE1: phase_1_mods,
     }
 
     run_state_test_generators(runner_name="genesis", specs=specs, all_mods=all_mods)
diff --git a/tests/generators/operations/main.py b/tests/generators/operations/main.py
index f5c181710..f00c4f894 100644
--- a/tests/generators/operations/main.py
+++ b/tests/generators/operations/main.py
@@ -1,11 +1,10 @@
 from eth2spec.gen_helpers.gen_from_tests.gen import run_state_test_generators
 from eth2spec.phase0 import spec as spec_phase0
 from eth2spec.altair import spec as spec_altair
-from eth2spec.phase1 import spec as spec_phase1
-from eth2spec.test.context import PHASE0, PHASE1, ALTAIR
+from eth2spec.test.context import PHASE0, ALTAIR
 
 
-specs = (spec_phase0, spec_altair, spec_phase1)
+specs = (spec_phase0, spec_altair)
 
 
 if __name__ == "__main__":
@@ -23,19 +22,19 @@ if __name__ == "__main__":
         ]},
         **phase_0_mods,
     }  # also run the previous phase 0 tests
-    phase_1_mods = {**{key: 'eth2spec.test.phase1.block_processing.test_process_' + key for key in [
-        'attestation',
-        'chunk_challenge',
-        'custody_key_reveal',
-        'custody_slashing',
-        'early_derived_secret_reveal',
-        'shard_transition',
-    ]}, **phase_0_mods}  # also run the previous phase 0 tests (but against phase 1 spec)
+
+    # TODO Custody Game testgen is disabled for now
+    # custody_game_mods = {**{key: 'eth2spec.test.custody_game.block_processing.test_process_' + key for key in [
+    #     'attestation',
+    #     'chunk_challenge',
+    #     'custody_key_reveal',
+    #     'custody_slashing',
+    #     'early_derived_secret_reveal',
+    # ]}, **phase_0_mods}  # also run the previous phase 0 tests (but against custody game spec)
 
     all_mods = {
         PHASE0: phase_0_mods,
         ALTAIR: altair_mods,
-        PHASE1: phase_1_mods,
     }
 
     run_state_test_generators(runner_name="operations", specs=specs, all_mods=all_mods)
diff --git a/tests/generators/rewards/main.py b/tests/generators/rewards/main.py
index 3a7e8f63d..d8115f4cb 100644
--- a/tests/generators/rewards/main.py
+++ b/tests/generators/rewards/main.py
@@ -1,11 +1,10 @@
 from eth2spec.gen_helpers.gen_from_tests.gen import run_state_test_generators
 from eth2spec.phase0 import spec as spec_phase0
 from eth2spec.altair import spec as spec_altair
-from eth2spec.phase1 import spec as spec_phase1
-from eth2spec.test.context import PHASE0, PHASE1, ALTAIR
+from eth2spec.test.context import PHASE0, ALTAIR
 
 
-specs = (spec_phase0, spec_altair, spec_phase1)
+specs = (spec_phase0, spec_altair)
 
 
 if __name__ == "__main__":
@@ -14,14 +13,12 @@ if __name__ == "__main__":
         'leak',
         'random',
     ]}
-    # No additional altair or phase 1 specific rewards tests, yet.
+    # No additional altair specific rewards tests, yet.
     altair_mods = phase_0_mods
-    phase_1_mods = phase_0_mods
 
     all_mods = {
         PHASE0: phase_0_mods,
         ALTAIR: altair_mods,
-        PHASE1: phase_1_mods,
     }
 
     run_state_test_generators(runner_name="rewards", specs=specs, all_mods=all_mods)
diff --git a/tests/generators/sanity/main.py b/tests/generators/sanity/main.py
index a0ec2aaae..90f9a00df 100644
--- a/tests/generators/sanity/main.py
+++ b/tests/generators/sanity/main.py
@@ -1,12 +1,11 @@
 from eth2spec.phase0 import spec as spec_phase0
 from eth2spec.altair import spec as spec_altair
-from eth2spec.phase1 import spec as spec_phase1
-from eth2spec.test.context import PHASE0, PHASE1, ALTAIR
+from eth2spec.test.context import PHASE0, ALTAIR
 
 from eth2spec.gen_helpers.gen_from_tests.gen import run_state_test_generators
 
 
-specs = (spec_phase0, spec_altair, spec_phase1)
+specs = (spec_phase0, spec_altair)
 
 
 if __name__ == "__main__":
@@ -17,15 +16,10 @@ if __name__ == "__main__":
     altair_mods = {**{key: 'eth2spec.test.altair.sanity.test_' + key for key in [
         'blocks',
     ]}, **phase_0_mods}  # also run the previous phase 0 tests
-    phase_1_mods = {**{key: 'eth2spec.test.phase1.sanity.test_' + key for key in [
-        'blocks',  # more phase 1 specific block tests
-        'shard_blocks',
-    ]}, **phase_0_mods}  # also run the previous phase 0 tests (but against phase 1 spec)
 
     all_mods = {
         PHASE0: phase_0_mods,
         ALTAIR: altair_mods,
-        PHASE1: phase_1_mods,
     }
 
     run_state_test_generators(runner_name="sanity", specs=specs, all_mods=all_mods)
diff --git a/tests/generators/ssz_static/main.py b/tests/generators/ssz_static/main.py
index e06e3edc8..77a88a8cd 100644
--- a/tests/generators/ssz_static/main.py
+++ b/tests/generators/ssz_static/main.py
@@ -8,9 +8,8 @@ from eth2spec.gen_helpers.gen_base import gen_runner, gen_typing
 from eth2spec.debug import random_value, encode
 from eth2spec.config import config_util
 from eth2spec.phase0 import spec as spec_phase0
-from eth2spec.phase1 import spec as spec_phase1
 from eth2spec.altair import spec as spec_altair
-from eth2spec.test.context import PHASE1, ALTAIR, TESTGEN_FORKS, MINIMAL, MAINNET
+from eth2spec.test.context import ALTAIR, TESTGEN_FORKS, MINIMAL, MAINNET
 from eth2spec.utils.ssz.ssz_typing import Container
 from eth2spec.utils.ssz.ssz_impl import (
     hash_tree_root,
@@ -64,15 +63,12 @@ def create_provider(fork_name, config_name: str, seed: int, mode: random_value.R
         # Apply changes to presets, this affects some of the vector types.
         config_util.prepare_config(configs_path, config_name)
         reload(spec_phase0)
-        reload(spec_phase1)
         reload(spec_altair)
         return config_name
 
     def cases_fn() -> Iterable[gen_typing.TestCase]:
         count = cases_if_random if chaos or mode.is_changing() else 1
         spec = spec_phase0
-        if fork_name == PHASE1:
-            spec = spec_phase1
         if fork_name == ALTAIR:
             spec = spec_altair