diff --git a/news/4473.feature b/news/4473.feature
new file mode 100644
index 00000000000..5e93d322496
--- /dev/null
+++ b/news/4473.feature
@@ -0,0 +1,4 @@
+pip now retries on more HTTP status codes, for intermittent failures.
+
+Previously, it only retried on the standard 503. Now, it also retries on 500
+(transient failures on AWS S3), 520 and 527 (transient failures on Cloudflare).
diff --git a/src/pip/_internal/download.py b/src/pip/_internal/download.py
index 621dea7e3ce..180ea77bfaf 100644
--- a/src/pip/_internal/download.py
+++ b/src/pip/_internal/download.py
@@ -348,7 +348,9 @@ def __init__(self, *args, **kwargs):
             # connection got interrupted in some way. A 503 error in general
             # is typically considered a transient error so we'll go ahead and
             # retry it.
-            status_forcelist=[503],
+            # A 500 may indicate transient errror in Amazon S3
+            # A 520 or 527 - may indicate transient errror in CloudFlare
+            status_forcelist=[500, 503, 520, 527],
 
             # Add a small amount of back off between failed requests in
             # order to prevent hammering the service.