diff --git a/test/fixtures/test-runner/plan/less.mjs b/test/fixtures/test-runner/plan/less.mjs
new file mode 100644
index 00000000000000..5f482d019428de
--- /dev/null
+++ b/test/fixtures/test-runner/plan/less.mjs
@@ -0,0 +1,7 @@
+import test from 'node:test';
+
+test('less assertions than planned', (t) => {
+  t.plan(2);
+  t.assert.ok(true, 'only one assertion');
+  // Missing second assertion
+});
diff --git a/test/fixtures/test-runner/plan/match.mjs b/test/fixtures/test-runner/plan/match.mjs
new file mode 100644
index 00000000000000..eb7e64fa68be16
--- /dev/null
+++ b/test/fixtures/test-runner/plan/match.mjs
@@ -0,0 +1,7 @@
+import test from 'node:test';
+
+test('matching assertions', (t) => {
+  t.plan(2);
+  t.assert.ok(true, 'first assertion');
+  t.assert.ok(true, 'second assertion');
+});
diff --git a/test/fixtures/test-runner/plan/more.mjs b/test/fixtures/test-runner/plan/more.mjs
new file mode 100644
index 00000000000000..deb4fb7f9ec4b9
--- /dev/null
+++ b/test/fixtures/test-runner/plan/more.mjs
@@ -0,0 +1,7 @@
+import test from 'node:test';
+
+test('more assertions than planned', (t) => {
+  t.plan(1);
+  t.assert.ok(true, 'first assertion');
+  t.assert.ok(true, 'extra assertion'); // This should cause failure
+});
diff --git a/test/fixtures/test-runner/plan/nested-subtests.mjs b/test/fixtures/test-runner/plan/nested-subtests.mjs
new file mode 100644
index 00000000000000..61fc11b6278243
--- /dev/null
+++ b/test/fixtures/test-runner/plan/nested-subtests.mjs
@@ -0,0 +1,14 @@
+import test from 'node:test';
+
+test('deeply nested tests', async (t) => {
+  t.plan(1);
+
+  await t.test('level 1', async (t) => {
+    t.plan(1);
+
+    await t.test('level 2', (t) => {
+      t.plan(1);
+      t.assert.ok(true, 'deepest assertion');
+    });
+  });
+});
diff --git a/test/fixtures/test-runner/plan/plan-via-options.mjs b/test/fixtures/test-runner/plan/plan-via-options.mjs
new file mode 100644
index 00000000000000..fd27f75bd166c6
--- /dev/null
+++ b/test/fixtures/test-runner/plan/plan-via-options.mjs
@@ -0,0 +1,9 @@
+import test from 'node:test';
+
+test('failing planning by options', { plan: 1 }, () => {
+  // Should fail - no assertions
+});
+
+test('passing planning by options', { plan: 1 }, (t) => {
+  t.assert.ok(true);
+});
diff --git a/test/fixtures/test-runner/plan/streaming.mjs b/test/fixtures/test-runner/plan/streaming.mjs
new file mode 100644
index 00000000000000..4a6625af8afc7e
--- /dev/null
+++ b/test/fixtures/test-runner/plan/streaming.mjs
@@ -0,0 +1,20 @@
+import test from 'node:test';
+import { Readable } from 'node:stream';
+
+test('planning with streams', (t, done) => {
+  function* generate() {
+    yield 'a';
+    yield 'b';
+    yield 'c';
+  }
+  const expected = ['a', 'b', 'c'];
+  t.plan(expected.length);
+  const stream = Readable.from(generate());
+  stream.on('data', (chunk) => {
+    t.assert.strictEqual(chunk, expected.shift());
+  });
+
+  stream.on('end', () => {
+    done();
+  });
+});
diff --git a/test/fixtures/test-runner/plan/subtest.mjs b/test/fixtures/test-runner/plan/subtest.mjs
new file mode 100644
index 00000000000000..e87757029829f5
--- /dev/null
+++ b/test/fixtures/test-runner/plan/subtest.mjs
@@ -0,0 +1,9 @@
+import test from 'node:test';
+
+test('parent test', async (t) => {
+  t.plan(1);
+  await t.test('child test', (t) => {
+    t.plan(1);
+    t.assert.ok(true, 'child assertion');
+  });
+});
diff --git a/test/fixtures/test-runner/plan/timeout-basic.mjs b/test/fixtures/test-runner/plan/timeout-basic.mjs
new file mode 100644
index 00000000000000..ab9c5cf92d1cf8
--- /dev/null
+++ b/test/fixtures/test-runner/plan/timeout-basic.mjs
@@ -0,0 +1,15 @@
+import test from 'node:test';
+
+test('planning with wait should PASS within timeout', async (t) => {
+  t.plan(1, { wait: 5000 });
+  setTimeout(() => {
+    t.assert.ok(true);
+  }, 250);
+});
+
+test('planning with wait should FAIL within timeout', async (t) => {
+  t.plan(1, { wait: 5000 });
+  setTimeout(() => {
+    t.assert.ok(false);
+  }, 250);
+});
diff --git a/test/fixtures/test-runner/plan/timeout-expired.mjs b/test/fixtures/test-runner/plan/timeout-expired.mjs
new file mode 100644
index 00000000000000..3d96df79498425
--- /dev/null
+++ b/test/fixtures/test-runner/plan/timeout-expired.mjs
@@ -0,0 +1,8 @@
+import test from 'node:test';
+
+test('planning should FAIL when wait time expires before plan is met', (t) => {
+  t.plan(2, { wait: 500 });
+  setTimeout(() => {
+    t.assert.ok(true);
+  }, 30_000).unref();
+});
diff --git a/test/fixtures/test-runner/plan/timeout-wait-false.mjs b/test/fixtures/test-runner/plan/timeout-wait-false.mjs
new file mode 100644
index 00000000000000..b9830ca8286d0c
--- /dev/null
+++ b/test/fixtures/test-runner/plan/timeout-wait-false.mjs
@@ -0,0 +1,11 @@
+import test from 'node:test';
+
+test('should not wait for assertions and fail immediately', async (t) => {
+  t.plan(1, { wait: false });
+
+  // Set up an async operation that won't complete before the test finishes
+  // Since wait:false, the test should fail immediately without waiting
+  setTimeout(() => {
+    t.assert.ok(true);
+  }, 1000).unref();
+});
diff --git a/test/fixtures/test-runner/plan/timeout-wait-true.mjs b/test/fixtures/test-runner/plan/timeout-wait-true.mjs
new file mode 100644
index 00000000000000..cc0dd8d8ab0d67
--- /dev/null
+++ b/test/fixtures/test-runner/plan/timeout-wait-true.mjs
@@ -0,0 +1,17 @@
+import test from 'node:test';
+
+test('should pass when assertions are eventually met', async (t) => {
+  t.plan(1, { wait: true });
+
+  setTimeout(() => {
+    t.assert.ok(true);
+  }, 250);
+});
+
+test('should fail when assertions fail', async (t) => {
+  t.plan(1, { wait: true });
+
+  setTimeout(() => {
+    t.assert.ok(false);
+  }, 250).unref();
+});
diff --git a/test/parallel/test-runner-plan.mjs b/test/parallel/test-runner-plan.mjs
new file mode 100644
index 00000000000000..85f8f570453c0c
--- /dev/null
+++ b/test/parallel/test-runner-plan.mjs
@@ -0,0 +1,171 @@
+import * as common from '../common/index.mjs';
+import * as fixtures from '../common/fixtures.mjs';
+import { describe, it, run } from 'node:test';
+import { join } from 'node:path';
+
+const testFixtures = fixtures.path('test-runner', 'plan');
+
+describe('input validation', () => {
+  it('throws if options is not an object', (t) => {
+    t.assert.throws(() => {
+      t.plan(1, null);
+    }, {
+      code: 'ERR_INVALID_ARG_TYPE',
+      message: /The "options" argument must be of type object/,
+    });
+  });
+
+  it('throws if options.wait is not a number or a boolean', (t) => {
+    t.assert.throws(() => {
+      t.plan(1, { wait: 'foo' });
+    }, {
+      code: 'ERR_INVALID_ARG_TYPE',
+      message: /The "options\.wait" property must be one of type boolean or number\. Received type string/,
+    });
+  });
+
+  it('throws if count is not a number', (t) => {
+    t.assert.throws(() => {
+      t.plan('foo');
+    }, {
+      code: 'ERR_INVALID_ARG_TYPE',
+      message: /The "count" argument must be of type number/,
+    });
+  });
+});
+
+describe('test planning', () => {
+  it('should pass when assertions match plan', async () => {
+    const stream = run({
+      files: [join(testFixtures, 'match.mjs')]
+    });
+
+    stream.on('test:fail', common.mustNotCall());
+    stream.on('test:pass', common.mustCall(1));
+
+    // eslint-disable-next-line no-unused-vars
+    for await (const _ of stream);
+  });
+
+  it('should fail when less assertions than planned', async () => {
+    const stream = run({
+      files: [join(testFixtures, 'less.mjs')]
+    });
+
+    stream.on('test:fail', common.mustCall(1));
+    stream.on('test:pass', common.mustNotCall());
+
+    // eslint-disable-next-line no-unused-vars
+    for await (const _ of stream);
+  });
+
+  it('should fail when more assertions than planned', async () => {
+    const stream = run({
+      files: [join(testFixtures, 'more.mjs')]
+    });
+
+    stream.on('test:fail', common.mustCall(1));
+    stream.on('test:pass', common.mustNotCall());
+
+    // eslint-disable-next-line no-unused-vars
+    for await (const _ of stream);
+  });
+
+  it('should handle plan with subtests correctly', async () => {
+    const stream = run({
+      files: [join(testFixtures, 'subtest.mjs')]
+    });
+
+    stream.on('test:fail', common.mustNotCall());
+    stream.on('test:pass', common.mustCall(2)); // Parent + child test
+
+    // eslint-disable-next-line no-unused-vars
+    for await (const _ of stream);
+  });
+
+  it('should handle plan via options', async () => {
+    const stream = run({
+      files: [join(testFixtures, 'plan-via-options.mjs')]
+    });
+
+    stream.on('test:fail', common.mustCall(1));
+    stream.on('test:pass', common.mustCall(1));
+
+    // eslint-disable-next-line no-unused-vars
+    for await (const _ of stream);
+  });
+
+  it('should handle streaming with plan', async () => {
+    const stream = run({
+      files: [join(testFixtures, 'streaming.mjs')]
+    });
+
+    stream.on('test:fail', common.mustNotCall());
+    stream.on('test:pass', common.mustCall(1));
+
+    // eslint-disable-next-line no-unused-vars
+    for await (const _ of stream);
+  });
+
+  it('should handle nested subtests with plan', async () => {
+    const stream = run({
+      files: [join(testFixtures, 'nested-subtests.mjs')]
+    });
+
+    stream.on('test:fail', common.mustNotCall());
+    stream.on('test:pass', common.mustCall(3)); // Parent + 2 levels of nesting
+
+    // eslint-disable-next-line no-unused-vars
+    for await (const _ of stream);
+  });
+
+  describe('with timeout', () => {
+    it('should handle basic timeout scenarios', async () => {
+      const stream = run({
+        files: [join(testFixtures, 'timeout-basic.mjs')]
+      });
+
+      stream.on('test:fail', common.mustCall(1));
+      stream.on('test:pass', common.mustCall(1));
+
+      // eslint-disable-next-line no-unused-vars
+      for await (const _ of stream);
+    });
+
+    it('should fail when timeout expires before plan is met', async (t) => {
+      const stream = run({
+        files: [join(testFixtures, 'timeout-expired.mjs')]
+      });
+
+      stream.on('test:fail', common.mustCall(1));
+      stream.on('test:pass', common.mustNotCall());
+
+      // eslint-disable-next-line no-unused-vars
+      for await (const _ of stream);
+    });
+
+    it('should handle wait:true option specifically', async () => {
+      const stream = run({
+        files: [join(testFixtures, 'timeout-wait-true.mjs')]
+      });
+
+      stream.on('test:fail', common.mustCall(1));
+      stream.on('test:pass', common.mustCall(1));
+
+      // eslint-disable-next-line no-unused-vars
+      for await (const _ of stream);
+    });
+
+    it('should handle wait:false option (should not wait)', async () => {
+      const stream = run({
+        files: [join(testFixtures, 'timeout-wait-false.mjs')]
+      });
+
+      stream.on('test:fail', common.mustCall(1)); // Fails because plan is not met immediately
+      stream.on('test:pass', common.mustNotCall());
+
+      // eslint-disable-next-line no-unused-vars
+      for await (const _ of stream);
+    });
+  });
+});