diff --git a/python-threatexchange/threatexchange/exchanges/impl/ncmec_api.py b/python-threatexchange/threatexchange/exchanges/impl/ncmec_api.py
index eedd737f5..ef78853c0 100644
--- a/python-threatexchange/threatexchange/exchanges/impl/ncmec_api.py
+++ b/python-threatexchange/threatexchange/exchanges/impl/ncmec_api.py
@@ -39,8 +39,8 @@ class NCMECCheckpoint(
 
     # The biggest value of "to", and the next "from"
     get_entries_max_ts: int
-    next_fetch: str
-    last_fetch_time: int
+    next_fetch: t.Optional[str] = ""
+    last_fetch_time: t.Optional[int] = 0
 
     def get_progress_timestamp(self) -> t.Optional[int]:
         return self.get_entries_max_ts
@@ -245,7 +245,7 @@ def fetch_iter(
         next_fetch = ""
         if checkpoint is not None:
             start_time = checkpoint.get_entries_max_ts
-            next_fetch = checkpoint.next_fetch
+            next_fetch = checkpoint.next_fetch or ""
         # Avoid being exactly at end time for updates showing up multiple
         # times in the fetch, since entries are not ordered by time
         end_time = int(time.time()) - 5
@@ -324,9 +324,8 @@ def log(event: str) -> None:
                         ),
                     )
                     current_next_fetch = entry.next
-                    updates = []
-                else:
-                    updates.extend(entry.updates)
+                    break
+                updates.extend(entry.updates)
             else:  # AKA a successful fetch
                 # If we're hovering near the single-fetch limit for a period
                 # of time, we can likely safely expand our range.
diff --git a/python-threatexchange/threatexchange/exchanges/tests/test_state_compatibility.py b/python-threatexchange/threatexchange/exchanges/tests/test_state_compatibility.py
index 994d10a51..0a26f2746 100644
--- a/python-threatexchange/threatexchange/exchanges/tests/test_state_compatibility.py
+++ b/python-threatexchange/threatexchange/exchanges/tests/test_state_compatibility.py
@@ -147,8 +147,23 @@ def get_NCMECCheckpoint() -> t.Tuple[NCMECCheckpoint, t.Sequence[object]]:
     ## Current
     max_ts = 1197433091
 
+    current = NCMECCheckpoint(
+        get_entries_max_ts=max_ts, next_fetch="", last_fetch_time=0
+    )
+
     # 1.0.x
-    current = NCMECCheckpoint(get_entries_max_ts=max_ts, next="", last_fetch_time=0)
+    @dataclass
+    class NCMECCheckpointWithoutNext(FetchCheckpointBase):
+        """
+        0.99.x => 1.0.0
+
+        get_entries_max_ts: int =>
+            get_entries_max_ts: int
+            next_fetch: str
+            last_fetch_time: int
+        """
+
+        get_entries_max_ts: int
 
     # 0.99.x
     @dataclass
@@ -161,9 +176,10 @@ class NCMECCheckpointTsMoved(FetchCheckpointBase):
 
         max_timestamp: int
 
+    checkpoint_without_next = NCMECCheckpointWithoutNext(get_entries_max_ts=max_ts)
     ts_moved = NCMECCheckpointTsMoved(max_timestamp=max_ts)
 
-    return (current, [ts_moved])
+    return (current, [checkpoint_without_next, ts_moved])
 
 
 @pytest.mark.parametrize(