diff --git a/lib/stylelint-todo.js b/lib/stylelint-todo.js
new file mode 100644
index 0000000000..1340538578
--- /dev/null
+++ b/lib/stylelint-todo.js
@@ -0,0 +1,38 @@
+const semver = require('semver')
+const stylelint = require('stylelint')
+
+const ruleName = 'primer-css/TODO'
+const pattern = /\bTODO@([^:]+):\s+(.+)$/
+
+const messages = stylelint.utils.ruleMessages(ruleName, {
+  rejected: message => message
+})
+
+module.exports = stylelint.createPlugin(ruleName, (enabled, options = {}) => {
+  const {currentVersion} = options
+  if (!currentVersion) {
+    // eslint-disable-next-line no-console
+    console.warn(`No "currentVersion" supplied to ${ruleName}; bailing`)
+    return () => null
+  }
+
+  let match
+  return (root, result) => {
+    root.walkComments(node => {
+      if ((match = node.text.match(pattern))) {
+        // eslint-disable-next-line no-unused-vars
+        const [substr, todoVersion, message] = match
+        if (semver.lte(todoVersion, currentVersion)) {
+          stylelint.utils.report({
+            message: messages.rejected(
+              `Unresolved TODO comment: "${message}" (expected to be resolved in "${todoVersion}")`
+            ),
+            node,
+            result,
+            ruleName
+          })
+        }
+      }
+    })
+  }
+})
diff --git a/stylelint.config.js b/stylelint.config.js
index 2ee89ebdfe..0b48eb1e78 100644
--- a/stylelint.config.js
+++ b/stylelint.config.js
@@ -1,7 +1,11 @@
+const currentVersion = process.env.PRIMER_VERSION || require('./package.json').version
+
 module.exports = {
   extends: ['stylelint-config-primer'],
+  plugins: ['./lib/stylelint-todo'],
   syntax: 'scss',
   rules: {
-    'primer/no-override': false
+    'primer/no-override': false,
+    'primer-css/TODO': [true, {currentVersion, severity: 'error'}]
   }
 }