diff --git a/CHANGELOG.md b/CHANGELOG.md
index 80056f2..92f63a0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -177,4 +177,7 @@
 - added primary diagnosis condition mv, registry compile/drift checks, postgres CI coverage, and schema snapshot artifact export
 
 ## 0.4.7
-- fixed treatment envelope window issues
\ No newline at end of file
+- fixed treatment envelope window issues
+
+## 0.4.8 
+- treatment envelope should left join to death (bug fix)
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index b95d5c1..595600a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "omop-constructs"
-version = "0.4.7"
+version = "0.4.8"
 description = "For building complex constructs on top of the omop-alchemy library."
 readme = "README.md"
 authors = [
diff --git a/src/omop_constructs/alchemy/episodes/treatment_envelope_query.py b/src/omop_constructs/alchemy/episodes/treatment_envelope_query.py
index ac8a36a..cd7c5aa 100644
--- a/src/omop_constructs/alchemy/episodes/treatment_envelope_query.py
+++ b/src/omop_constructs/alchemy/episodes/treatment_envelope_query.py
@@ -102,12 +102,18 @@
 
 
 # ---------------------------------------------------------------------------
-# treatment_envelope — person-level envelope joined to death
+# treatment_envelope — condition-episode spine joined to death
 # ---------------------------------------------------------------------------
+# The spine is treatment_window (rooted at ModifiedCondition / ConditionEpisodeMV)
+# so that every condition episode appears regardless of mortality status.
+# Death is outer-joined on person_id to attach death_datetime where it exists.
+# Using Death as the spine instead would silently exclude all living patients —
+# treatment timing scalars such as days_from_dx_to_treatment are meaningful for
+# the full cohort, not only for those with a death record.
 treatment_envelope = (
     sa.select(
         sa.func.row_number().over().label('mv_id'),
-        Death.person_id,
+        treatment_window.c.person_id,
         treatment_window.c.condition_episode,
         treatment_window.c.condition_start_date,
         treatment_window.c.concurrent_chemort,
@@ -135,8 +141,8 @@
         ).label('latest_treatment'),
         Death.death_datetime,
     )
-    .select_from(Death)
-    .join(treatment_window, treatment_window.c.person_id == Death.person_id, isouter=True)
+    .select_from(treatment_window)
+    .join(Death, Death.person_id == treatment_window.c.person_id, isouter=True)
     .subquery()
 )
 
diff --git a/uv.lock b/uv.lock
index 3d40a05..efd7362 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1407,7 +1407,7 @@ postgres = [
 
 [[package]]
 name = "omop-constructs"
-version = "0.4.7"
+version = "0.4.8"
 source = { editable = "." }
 dependencies = [
     { name = "omop-alchemy", extra = ["postgres"] },