diff --git a/changelog_unreleased/typescript/18738.md b/changelog_unreleased/typescript/18738.md
new file mode 100644
index 000000000..bd96e5acc
--- /dev/null
+++ b/changelog_unreleased/typescript/18738.md
@@ -0,0 +1,19 @@
+#### Print semicolon before type assertion in `no-semi` mode (#18738 by @fisker)
+
+<!-- prettier-ignore -->
+```tsx
+// Input
+a;
+<b>c;
+
+// Prettier stable (First format, --no-semi)
+a
+<b>c
+
+// Prettier stable (Second format, --no-semi)
+a < b > c
+
+// Prettier main
+a
+;<b>c
+```
diff --git a/src/language-js/print/type-assertion.js b/src/language-js/print/type-assertion.js
index d7c09b87a..9869df5e5 100644
--- a/src/language-js/print/type-assertion.js
+++ b/src/language-js/print/type-assertion.js
@@ -7,6 +7,9 @@ import {
 } from "../../document/index.js";
 import { isArrayExpression, isObjectExpression } from "../utilities/index.js";
 
+/*
+- `TSTypeAssertion` (TypeScript)
+*/
 function printTypeAssertion(path, options, print) {
   const { node } = path;
   const shouldBreakAfterCast = !(
diff --git a/src/language-js/semicolon/semicolon.js b/src/language-js/semicolon/semicolon.js
index b6c488035..ed62a76c5 100644
--- a/src/language-js/semicolon/semicolon.js
+++ b/src/language-js/semicolon/semicolon.js
@@ -39,12 +39,14 @@ function expressionNeedsASIProtection(path, options) {
   switch (node.type) {
     case "ParenthesizedExpression":
     case "TypeCastExpression":
+    case "TSTypeAssertion":
     case "ArrayExpression":
     case "ArrayPattern":
     case "TemplateLiteral":
     case "TemplateElement":
     case "RegExpLiteral":
       return true;
+
     case "ArrowFunctionExpression":
       if (!shouldPrintParamsWithoutParens(path, options)) {
         return true;
diff --git a/tests/format/typescript/no-semi/__snapshots__/format.test.js.snap b/tests/format/typescript/no-semi/__snapshots__/format.test.js.snap
index e13af981f..2d94c08d5 100644
--- a/tests/format/typescript/no-semi/__snapshots__/format.test.js.snap
+++ b/tests/format/typescript/no-semi/__snapshots__/format.test.js.snap
@@ -105,3 +105,64 @@ const el = ReactDOM.findDOMNode(ref);
 
 ================================================================================
 `;
+
+exports[`type-assertion.ts - {"semi":false} format 1`] = `
+====================================options=====================================
+parsers: ["typescript"]
+printWidth: 80
+semi: false
+                                                                                | printWidth
+=====================================input======================================
+// #14039
+a;
+<b>c;
+
+a;
+(<b>c).foo();
+
+a;
+<b>c + 1;
+
+=====================================output=====================================
+// #14039
+a
+;<b>c
+
+a
+;(<b>c).foo()
+
+a
+;<b>c + 1
+
+================================================================================
+`;
+
+exports[`type-assertion.ts format 1`] = `
+====================================options=====================================
+parsers: ["typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+// #14039
+a;
+<b>c;
+
+a;
+(<b>c).foo();
+
+a;
+<b>c + 1;
+
+=====================================output=====================================
+// #14039
+a;
+<b>c;
+
+a;
+(<b>c).foo();
+
+a;
+<b>c + 1;
+
+================================================================================
+`;
diff --git a/tests/format/typescript/no-semi/type-assertion.ts b/tests/format/typescript/no-semi/type-assertion.ts
new file mode 100644
index 000000000..11d85be4b
--- /dev/null
+++ b/tests/format/typescript/no-semi/type-assertion.ts
@@ -0,0 +1,9 @@
+// #14039
+a;
+<b>c;
+
+a;
+(<b>c).foo();
+
+a;
+<b>c + 1;