diff --git a/docs/plat-86/cfn-dispose.md b/docs/plat-86/cfn-dispose.md
index a40a5c7..7464b9d 100644
--- a/docs/plat-86/cfn-dispose.md
+++ b/docs/plat-86/cfn-dispose.md
@@ -23,3 +23,6 @@ Never run `cfn-stack-decommission.sh --execute` against these stacks. That scrip
 ## Script
 
 `scripts/plat86-cfn-dispose.sh` implements steps 1–4 with explicit confirms and post-checks.
+
+Retain-all templates exceed the CloudFormation CLI 51KB inline `--template-body` limit, so the script stages them to `s3://procurement-ingest-artifacts-011934824531/plat86-cfn-dispose/` and updates via `--template-url`.
+
diff --git a/scripts/plat86-cfn-dispose.sh b/scripts/plat86-cfn-dispose.sh
index 6b1bde8..f169819 100755
--- a/scripts/plat86-cfn-dispose.sh
+++ b/scripts/plat86-cfn-dispose.sh
@@ -20,6 +20,9 @@ PROFILE="${AWS_PROFILE:-seahaven-prod}"
 STACKS=(po-ingest WorkorderIngestStack procurement-api)
 PO_BUCKET="po-ingest-emails-011934824531"
 WO_BUCKET="workorder-ingest-emails-011934824531"
+# Staging for retain-all templates (inline --template-body is capped at 51KB).
+TEMPLATE_BUCKET="${PLAT86_TEMPLATE_BUCKET:-procurement-ingest-artifacts-011934824531}"
+TEMPLATE_PREFIX="plat86-cfn-dispose"
 MODE=""
 
 aws_cmd() {
@@ -126,10 +129,14 @@ for stack in "${STACKS[@]}"; do
     echo "dry-run: would update-stack ${stack} then delete-stack"
     continue
   fi
-  echo "==> update-stack ${stack} (retain-all)"
+  echo "==> update-stack ${stack} (retain-all via s3://${TEMPLATE_BUCKET})"
+  key="${TEMPLATE_PREFIX}/${stack}-retain-$(date -u +%Y%m%dT%H%M%SZ).json"
+  aws_cmd s3 cp "${work_dir}/${stack}.retain.json" "s3://${TEMPLATE_BUCKET}/${key}" >/dev/null
+  # us-east-1 regional URL form required by CloudFormation.
+  template_url="https://${TEMPLATE_BUCKET}.s3.${REGION}.amazonaws.com/${key}"
   aws_cmd cloudformation update-stack \
     --stack-name "${stack}" \
-    --template-body "file://${work_dir}/${stack}.retain.json" \
+    --template-url "${template_url}" \
     --capabilities CAPABILITY_NAMED_IAM \
     >/dev/null
   wait_stack "${stack}" "update-complete"