diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index a750f765..8a1db6d9 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -24,7 +24,7 @@ In order to add a feature to ``python-ndb``:
   documentation (in ``docs/``).
 
 - The feature must work fully on the following CPython versions:  2.7, 3.6
-  3.7, 3.8, and 3.9 on both UNIX and Windows.
+  3.7, 3.8, 3.9 and 3.10 on both UNIX and Windows.
 
 - The feature must not add unnecessary dependencies (where
   "unnecessary" is of course subjective, but new dependencies should
@@ -72,7 +72,7 @@ We use `nox <https://nox.readthedocs.io/en/latest/>`__ to instrument our tests.
 
 - To test your changes, run unit tests with ``nox``::
 
-    $ nox -s unit-3.7
+    $ nox -s unit-3.10
     $ nox -s unit-3.6
     $ ...
 
@@ -278,12 +278,14 @@ We support:
 -  `Python 3.7`_
 -  `Python 3.8`_
 -  `Python 3.9`_
+-  `Python 3.10`_
 
 .. _Python 2.7: https://docs.python.org/2.7/
 .. _Python 3.6: https://docs.python.org/3.6/
 .. _Python 3.7: https://docs.python.org/3.7/
 .. _Python 3.8: https://docs.python.org/3.8/
 .. _Python 3.9: https://docs.python.org/3.9/
+.. _Python 3.10: https://docs.python.org/3.10/
 
 
 Supported versions can be found in our ``noxfile.py`` `config`_.
diff --git a/README.md b/README.md
index 5c55d584..c1eadd95 100644
--- a/README.md
+++ b/README.md
@@ -22,4 +22,4 @@ run on other Python platforms as well.
 GA
 
 ### Officially Supported Python Versions
-Python 2.7 & Python 3.6, 3.7, 3.8, 3.9
+Python 2.7 & Python 3.6, 3.7, 3.8, 3.9, 3.10
diff --git a/noxfile.py b/noxfile.py
index 1bc484c0..e9e07011 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -26,8 +26,8 @@
 LOCAL_DEPS = ("google-api-core", "google-cloud-core")
 NOX_DIR = os.path.abspath(os.path.dirname(__file__))
 DEFAULT_INTERPRETER = "3.8"
-ALL_INTERPRETERS = ("2.7", "3.6", "3.7", "3.8", "3.9")
-PY3_INTERPRETERS = ("3.6", "3.7", "3.8", "3.9")
+ALL_INTERPRETERS = ("2.7", "3.6", "3.7", "3.8", "3.9", "3.10")
+PY3_INTERPRETERS = ("3.6", "3.7", "3.8", "3.9", "3.10")
 MAJOR_INTERPRETERS = ("2.7", "3.8")
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
 
@@ -59,6 +59,7 @@ def unit(session):
             [
                 "--cov=google.cloud.ndb",
                 "--cov=unit",
+                "--cov-append",
                 "--cov-config",
                 get_path(".coveragerc"),
                 "--cov-report=term-missing",
@@ -76,8 +77,6 @@ def unit(session):
 def cover(session):
     # Install all dependencies.
     session.install("coverage")
-    # THis variable is used to skip coverage by Python version
-    session.env["PY_VERSION"] = session.python[0]
     # Run coverage report.
     session.run("coverage", "report", "--fail-under=100", "--show-missing")
     # Erase cached coverage data.
diff --git a/setup.py b/setup.py
index 5798f628..6bf67e6a 100644
--- a/setup.py
+++ b/setup.py
@@ -61,6 +61,7 @@ def main():
             "Programming Language :: Python :: 3.7",
             "Programming Language :: Python :: 3.8",
             "Programming Language :: Python :: 3.9",
+            "Programming Language :: Python :: 3.10",
             "Programming Language :: Python :: 2",
             "Programming Language :: Python :: 2.7",
             "Operating System :: OS Independent",