diff --git a/components/text_sensor/index.rst b/components/text_sensor/index.rst
index c2a643442..d5379c67d 100644
--- a/components/text_sensor/index.rst
+++ b/components/text_sensor/index.rst
@@ -142,6 +142,25 @@ Search the current value of the text sensor for a string, and replace it with an
 
 The arguments are a list of substitutions, each in the form ``TO_FIND -> REPLACEMENT``.
 
+``map``
+*******
+
+Lookup the current value of the text sensor in a list, and return the matching item if found. 
+Does not change the value of the text sensor if the current value wasn't found.
+
+
+.. code-block:: yaml
+
+    # Example configuration entry
+    - platform: template
+      # ...
+      filters:
+        - map:
+          - high -> On
+          - low -> Off
+
+The arguments are a list of substitutions, each in the form ``LOOKUP -> REPLACEMENT``.
+
 ``lambda``
 **********