diff --git a/.nengobones.yml b/.nengobones.yml
index 0b0f5004..f86003a4 100644
--- a/.nengobones.yml
+++ b/.nengobones.yml
@@ -103,6 +103,7 @@ setup_py:
       - bones-generate=nengo_bones.scripts.generate_bones:main
       - bones-check=nengo_bones.scripts.check_bones:main
       - bones-pr-number=nengo_bones.scripts.pr_number:main
+      - bones-stale-branches=nengo_bones.scripts.stale_branches:main
   include_package_data: True
   # note: docs/tests_req are intentionally empty to test that the correct
   # requirements are built into the ci scripts
diff --git a/nengo_bones/scripts/stale_branches.py b/nengo_bones/scripts/stale_branches.py
new file mode 100644
index 00000000..93f99b16
--- /dev/null
+++ b/nengo_bones/scripts/stale_branches.py
@@ -0,0 +1,132 @@
+"""Retrieves a list of stale branches in a specific repository."""
+
+from collections import OrderedDict
+from datetime import datetime
+import os
+import random
+import time
+
+import click
+import requests
+from requests.exceptions import HTTPError, RequestException
+
+import nengo_bones
+
+import pdb
+
+
+class _backoff:
+    MAX_COUNTER = 5  # corresponds to a minute of waiting
+
+    def __init__(self):
+        self.counter = 0
+
+    def __call__(self):
+        fudge_ms = random.randint(0, 1000) / 1000
+        time.sleep(2 ** self.counter + fudge_ms)
+        self.counter = min(self.MAX_COUNTER, self.counter + 1)
+
+
+backoff = _backoff()
+
+
+class GitHubRequester:
+    def __init__(self):
+        username = os.getenv("BONES_GH_USER")
+        if username is None:
+            raise RuntimeError("Please export BONES_GH_USER")
+        token = os.getenv("BONES_GH_TOKEN")
+        if token is None:
+            raise RuntimeError("Please export BONES_GH_TOKEN")
+        self.session = requests.Session()
+        self.session.auth = (username, token)
+        self.session.headers = {
+            "User-Agent": "Nengo Bones v%s" % nengo_bones.__version__
+        }
+
+    def __call__(self, repo, endpoint):
+        resp = None
+        while resp is None:
+            try:
+                resp = self.session.get(
+                    "https://api.github.com/repos/%s/%s" % (repo, endpoint)
+                )
+                resp.raise_for_status()
+            except (HTTPError, RequestException) as e:
+                click.echo("%s" % e)
+                click.echo("Taking a short break and retrying...")
+                resp = None
+                backoff()
+        return resp.json()
+
+
+def get_stale_branches(repo, age_years=2):
+    """Get a list of branches older than ``age_years``."""
+
+    now = datetime.now()
+    req = GitHubRequester()
+
+    # Get list of branches
+    branches_json = req(repo, "branches")
+    branches = OrderedDict(
+        [
+            (branch["name"], {"age": None, "open_pr": None, "is_pr_base": False})
+            for branch in branches_json
+        ]
+    )
+
+    # Attach last modified date to branch
+    for branch in list(branches):
+        info = req(repo, "branches/%s" % branch)
+        if "name" not in info:
+            print(info)
+        assert info["name"] == branch
+        last_modified = datetime.strptime(
+            info["commit"]["commit"]["author"]["date"], "%Y-%m-%dT%H:%M:%SZ"
+        )
+        age = now - last_modified
+        if age.days >= age_years * 365:
+            branches[branch]["age"] = age
+        else:
+            del branches[branch]
+
+    # Attach PRs to branches
+    for pr in req(repo, "pulls?state=open"):
+        head_repo = "{}/{}".format(
+            pr["head"]["user"]["login"], pr["head"]["repo"]["name"]
+        )
+        head_branch = pr["head"]["ref"]
+        if head_repo == repo and head_branch in branches:
+            branches[head_branch]["open_pr"] = pr["html_url"]
+        base_ref = pr["base"]["ref"]
+        if base_ref in branches:
+            branches[base_ref]["is_pr_base"] = True
+
+    return branches
+
+
+@click.command()
+@click.argument("repo", required=False, default=None)
+@click.option("--conf-file", default=None, help="Filepath for config file")
+def main(repo, conf_file):
+    """Get a list of stale branches for a repository.
+
+    This is used for regular maintenance tasks.
+    """
+
+    if repo is None:
+        config = nengo_bones.config.load_config(conf_file)
+        repo = config["repo_name"]
+
+    click.echo("Asking GitHub for information about %s..." % (repo,))
+    stale_branches = get_stale_branches(repo)
+    for branch, info in stale_branches.items():
+        click.echo(
+            "Branch {} is {:.1f} months old.".format(branch, info["age"].days / 30)
+        )
+        if info["open_pr"] is not None:
+            click.echo("└─PR: {}".format(info["open_pr"]))
+
+
+if __name__ == "__main__":
+    main()  # pragma: no cover pylint: disable=no-value-for-parameter
diff --git a/setup.py b/setup.py
index fbc030d7..2ec8eae0 100755
--- a/setup.py
+++ b/setup.py
@@ -65,6 +65,7 @@ def read(*filenames, **kwargs):
             "bones-generate=nengo_bones.scripts.generate_bones:main",
             "bones-check=nengo_bones.scripts.check_bones:main",
             "bones-pr-number=nengo_bones.scripts.pr_number:main",
+            "bones-stale-branches=nengo_bones.scripts.stale_branches:main",
         ]
     },
     classifiers=[