diff --git a/jarca_ledger_mcp/application/account_valuation_service.py b/jarca_ledger_mcp/application/account_valuation_service.py
index 2f575fb..751172e 100644
--- a/jarca_ledger_mcp/application/account_valuation_service.py
+++ b/jarca_ledger_mcp/application/account_valuation_service.py
@@ -266,19 +266,19 @@ def correct_account_valuation(valuation_id: str, amount: int, correction_reason:
         source = conn.execute("SELECT * FROM account_valuations WHERE id=?", (valuation_id,)).fetchone()
         if source is None:
             return fail("not_found", "valuation not found")
+        preserved = {name: fields[name] if name in fields else source[name] for name in (
+            "currency", "valuation_kind", "source_type", "source_ref", "verification_status", "memo", "as_of_at", "timezone",
+            "cost_basis", "net_contributed", "reported_principal_kind", "reported_principal_label", "profit", "return_rate", "return_basis", "principal", "interest", "fee", "representative_liability_definition")}
         if idempotency_key:
             prior = conn.execute("SELECT * FROM account_valuations WHERE account_id=? AND idempotency_key=?", (source["account_id"], idempotency_key)).fetchone()
             if prior:
                 expected = {"amount": amount, "supersedes_id": valuation_id, "correction_reason": correction_reason.strip()}
-                expected.update({k: fields[k] for k in fields})
+                expected.update(preserved)
                 if all(prior[k] == v for k, v in expected.items() if k in prior.keys()):
                     return ok(valuation=_valuation(prior), reused=True)
                 return fail("idempotency_conflict", "idempotency_key already has a different payload", valuation=_valuation(prior))
         if conn.execute("SELECT 1 FROM account_valuations WHERE supersedes_id=?", (valuation_id,)).fetchone():
             return fail("correction_conflict", "valuation already has a correction")
-    preserved = {name: fields[name] if name in fields else source[name] for name in (
-        "currency", "valuation_kind", "source_type", "source_ref", "verification_status", "memo", "as_of_at", "timezone",
-        "cost_basis", "net_contributed", "reported_principal_kind", "reported_principal_label", "profit", "return_rate", "return_basis", "principal", "interest", "fee", "representative_liability_definition")}
     return register_account_valuation(
         source["account_id"], source["basis_date"], amount,
         **preserved,
diff --git a/jarca_ledger_mcp/application/assets_service.py b/jarca_ledger_mcp/application/assets_service.py
index 9ccccce..53db0fc 100644
--- a/jarca_ledger_mcp/application/assets_service.py
+++ b/jarca_ledger_mcp/application/assets_service.py
@@ -573,8 +573,10 @@ def get_asset_snapshot_report(basis_date: str = "", selection_policy: str = "exa
     basis = normalize_date(basis_date, default_today=True) if basis_date else current_kst_date().isoformat()
     with db(db_path) as conn:
         rows, close_metadata = _snapshot_rows_for_latest_run(conn, basis)
+        has_close_run = bool(close_metadata.get("snapshot_run_id"))
         snapshots = _snapshot_items(conn, basis) if rows else []
-        if close_metadata:
+        legacy_snapshots = snapshots if rows and not has_close_run else []
+        if has_close_run:
             summary = _summarize_valuation_items(snapshots, [])
             return ok(
                 basis_date=basis,
@@ -590,6 +592,19 @@ def get_asset_snapshot_report(basis_date: str = "", selection_policy: str = "exa
         manual_items, manual_excluded = _manual_asset_valuation_items(conn, basis_date=basis, selection_policy=selection_policy)
     included = account_items + manual_items
     excluded = account_excluded + manual_excluded
+    if not included and not excluded and legacy_snapshots:
+        summary = _summarize_valuation_items(legacy_snapshots, [])
+        return ok(
+            basis_date=basis,
+            source="legacy_asset_snapshots",
+            selection_policy=selection_policy,
+            close_status="legacy_read_only",
+            is_closed_snapshot=False,
+            snapshot_count=len(legacy_snapshots),
+            legacy_snapshot_row_count=len(legacy_snapshots),
+            close_metadata={"legacy": True, "snapshot_run_id": ""},
+            **summary,
+        )
     summary = _summarize_valuation_items(included, excluded)
     return ok(
         basis_date=basis,
@@ -598,6 +613,7 @@ def get_asset_snapshot_report(basis_date: str = "", selection_policy: str = "exa
         close_status="incomplete_draft" if excluded else "complete_exact",
         is_closed_snapshot=False,
         snapshot_count=0,
+        legacy_snapshot_row_count=len(legacy_snapshots),
         invalid_bucket_accounts=invalid_bucket_accounts,
         **summary,
     )
diff --git a/tests/test_asset_snapshots.py b/tests/test_asset_snapshots.py
index b01ebbc..34ac763 100644
--- a/tests/test_asset_snapshots.py
+++ b/tests/test_asset_snapshots.py
@@ -61,7 +61,9 @@ def test_snapshot_rows_are_append_only_and_timeseries_uses_same_formula(tmp_path
 
     may = service.get_asset_snapshot_report("2026-05-31", db_path=db_path)
     assert may["success"] is True
-    assert may["source"] == "asset_snapshots"
+    assert may["source"] == "legacy_asset_snapshots"
+    assert may["is_closed_snapshot"] is False
+    assert may["close_status"] == "legacy_read_only"
     assert may["snapshot_count"] == 3
     assert may["net_worth"] == 121_000_000
 
diff --git a/tests/test_issue_12_regressions.py b/tests/test_issue_12_regressions.py
index b82d7b0..989121f 100644
--- a/tests/test_issue_12_regressions.py
+++ b/tests/test_issue_12_regressions.py
@@ -180,6 +180,26 @@ def test_candidate_idempotency_rejects_changed_payload(tmp_path):
     assert conflict["error_code"] == "idempotency_conflict"
 
 
+def test_correction_idempotency_compares_effective_preserved_payload(tmp_path):
+    path = str(tmp_path / "ledger.sqlite3")
+    account = service.create_ledger_account("계좌", db_path=path)["account"]["id"]
+    original = service.register_account_valuation(
+        account, "2026-06-30", 100, memo="original",
+        verification_status="verified", idempotency_key="original", db_path=path,
+    )["valuation"]
+    first = service.correct_account_valuation(
+        original["id"], 200, "정정", memo="override",
+        idempotency_key="correction", db_path=path,
+    )
+    retry_with_omitted_memo = service.correct_account_valuation(
+        original["id"], 200, "정정",
+        idempotency_key="correction", db_path=path,
+    )
+    assert first["success"] is True
+    assert retry_with_omitted_memo["success"] is False
+    assert retry_with_omitted_memo["error_code"] == "idempotency_conflict"
+
+
 def test_valuation_currency_and_loan_kind_are_rejected(tmp_path):
     path = str(tmp_path / "ledger.sqlite3")
     bank = service.create_ledger_account("은행", currency="KRW", db_path=path)["account"]["id"]
@@ -331,6 +351,22 @@ def test_snapshot_rejects_bogus_selection_policy_and_manual_usd_is_excluded(tmp_
     assert any(item.get("reason") == "non_krw_without_fx" for item in report["excluded_items"])
 
 
+def test_legacy_snapshot_rows_do_not_override_live_authority_or_claim_closed(tmp_path):
+    path = str(tmp_path / "ledger.sqlite3")
+    service.create_asset_snapshot(
+        "2026-06-30", "account", "legacy", "legacy", 999, "cash", db_path=path,
+    )
+    account = service.create_ledger_account("현재 계좌", db_path=path)["account"]["id"]
+    service.register_account_valuation(
+        account, "2026-06-30", 100, verification_status="verified", db_path=path,
+    )
+    report = service.get_asset_snapshot_report("2026-06-30", db_path=path)
+    assert report["source"] == "live_authority"
+    assert report["is_closed_snapshot"] is False
+    assert report["total_assets"] == 100
+    assert report["legacy_snapshot_row_count"] == 1
+
+
 def test_account_write_rolls_back_when_conn_level_candidate_write_fails(tmp_path, monkeypatch):
     path = str(tmp_path / "ledger.sqlite3")
     import jarca_ledger_mcp.application.accounts_write_services as writes