diff --git a/doc/api/esm.md b/doc/api/esm.md
index 79793aef9cfe24..8b6f9c1e33fb46 100644
--- a/doc/api/esm.md
+++ b/doc/api/esm.md
@@ -7,6 +7,9 @@
 <!-- YAML
 added: v8.5.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/49531
+    description: ES modules within `module` package can be extensionless.
   - version: v20.0.0
     pr-url: https://github.com/nodejs/node/pull/44710
     description: Module customization hooks are executed off the main thread.
@@ -156,15 +159,6 @@ via the paths defined in [`"exports"`][].
 For details on these package resolution rules that apply to bare specifiers in
 the Node.js module resolution, see the [packages documentation](packages.md).
 
-### Mandatory file extensions
-
-A file extension must be provided when using the `import` keyword to resolve
-relative or absolute specifiers. Directory indexes (e.g. `'./startup/index.js'`)
-must also be fully specified.
-
-This behavior matches how `import` behaves in browser environments, assuming a
-typically configured server.
-
 ### URLs
 
 ES modules are resolved and cached as URLs. This means that special characters
@@ -1008,7 +1002,7 @@ _isImports_, _conditions_)
 > 5. Let _packageURL_ be the result of **LOOKUP\_PACKAGE\_SCOPE**(_url_).
 > 6. Let _pjson_ be the result of **READ\_PACKAGE\_JSON**(_packageURL_).
 > 7. If _pjson?.type_ exists and is _"module"_, then
->    1. If _url_ ends in _".js"_, then
+>    1. If _url_ ends in _".js"_ or lacks file extension, then
 >       1. Return _"module"_.
 >    2. Return **undefined**.
 > 8. Otherwise,
diff --git a/doc/api/packages.md b/doc/api/packages.md
index 09f32e6c160892..a900d1cc0abe33 100644
--- a/doc/api/packages.md
+++ b/doc/api/packages.md
@@ -393,8 +393,7 @@ and other JavaScript runtimes, using the extensionless style can result in
 bloated import map definitions. Explicit file extensions can avoid this issue by
 enabling the import map to utilize a [packages folder mapping][] to map multiple
 subpaths where possible instead of a separate map entry per package subpath
-export. This also mirrors the requirement of using [the full specifier path][]
-in relative and absolute import specifiers.
+export.
 
 ### Exports sugar
 
@@ -1352,4 +1351,3 @@ This field defines [subpath imports][] for the current package.
 [subpath imports]: #subpath-imports
 [supported package managers]: corepack.md#supported-package-managers
 [the dual CommonJS/ES module packages section]: #dual-commonjses-module-packages
-[the full specifier path]: esm.md#mandatory-file-extensions
diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index bed02da76a3bab..6ac77686569cbe 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -1690,13 +1690,7 @@ E('ERR_UNHANDLED_ERROR',
 E('ERR_UNKNOWN_BUILTIN_MODULE', 'No such built-in module: %s', Error);
 E('ERR_UNKNOWN_CREDENTIAL', '%s identifier does not exist: %s', Error);
 E('ERR_UNKNOWN_ENCODING', 'Unknown encoding: %s', TypeError);
-E('ERR_UNKNOWN_FILE_EXTENSION', (ext, path, suggestion) => {
-  let msg = `Unknown file extension "${ext}" for ${path}`;
-  if (suggestion) {
-    msg += `. ${suggestion}`;
-  }
-  return msg;
-}, TypeError);
+E('ERR_UNKNOWN_FILE_EXTENSION', 'Unknown file extension %s for %s', TypeError);
 E('ERR_UNKNOWN_MODULE_FORMAT', 'Unknown module format: %s for URL %s',
   RangeError);
 E('ERR_UNKNOWN_SIGNAL', 'Unknown signal: %s', TypeError);
diff --git a/lib/internal/modules/esm/get_format.js b/lib/internal/modules/esm/get_format.js
index 4ac9c011d153f4..4ee7725db44f3f 100644
--- a/lib/internal/modules/esm/get_format.js
+++ b/lib/internal/modules/esm/get_format.js
@@ -7,7 +7,6 @@ const {
   StringPrototypeCharCodeAt,
   StringPrototypeSlice,
 } = primordials;
-const { basename, relative } = require('path');
 const { getOptionValue } = require('internal/options');
 const {
   extensionFormatMap,
@@ -16,7 +15,7 @@ const {
 
 const experimentalNetworkImports =
   getOptionValue('--experimental-network-imports');
-const { getPackageType, getPackageScopeConfig } = require('internal/modules/esm/resolve');
+const { getPackageType } = require('internal/modules/esm/resolve');
 const { fileURLToPath } = require('internal/url');
 const { ERR_UNKNOWN_FILE_EXTENSION } = require('internal/errors').codes;
 
@@ -74,7 +73,7 @@ function extname(url) {
  */
 function getFileProtocolModuleFormat(url, context, ignoreErrors) {
   const ext = extname(url);
-  if (ext === '.js') {
+  if (ext === '.js' || ext === '') {
     return getPackageType(url) === 'module' ? 'module' : 'commonjs';
   }
 
@@ -83,20 +82,9 @@ function getFileProtocolModuleFormat(url, context, ignoreErrors) {
 
   // Explicit undefined return indicates load hook should rerun format check
   if (ignoreErrors) { return undefined; }
+
   const filepath = fileURLToPath(url);
-  let suggestion = '';
-  if (getPackageType(url) === 'module' && ext === '') {
-    const config = getPackageScopeConfig(url);
-    const fileBasename = basename(filepath);
-    const relativePath = StringPrototypeSlice(relative(config.pjsonPath, filepath), 1);
-    suggestion = 'Loading extensionless files is not supported inside of ' +
-      '"type":"module" package.json contexts. The package.json file ' +
-      `${config.pjsonPath} caused this "type":"module" context. Try ` +
-      `changing ${filepath} to have a file extension. Note the "bin" ` +
-      'field of package.json can point to a file with an extension, for example ' +
-      `{"type":"module","bin":{"${fileBasename}":"${relativePath}.js"}}`;
-  }
-  throw new ERR_UNKNOWN_FILE_EXTENSION(ext, filepath, suggestion);
+  throw new ERR_UNKNOWN_FILE_EXTENSION(ext, filepath);
 }
 
 /**
diff --git a/test/es-module/test-esm-unknown-or-no-extension.js b/test/es-module/test-esm-unknown-or-no-extension.js
deleted file mode 100644
index 3f0660e5aa9225..00000000000000
--- a/test/es-module/test-esm-unknown-or-no-extension.js
+++ /dev/null
@@ -1,36 +0,0 @@
-'use strict';
-
-const { spawnPromisified } = require('../common');
-const fixtures = require('../common/fixtures.js');
-const assert = require('node:assert');
-const { execPath } = require('node:process');
-const { describe, it } = require('node:test');
-
-
-// In a "type": "module" package scope, files with unknown extensions or no
-// extensions should throw; both when used as a main entry point and also when
-// referenced via `import`.
-describe('ESM: extensionless and unknown specifiers', { concurrency: true }, () => {
-  for (
-    const fixturePath of [
-      '/es-modules/package-type-module/noext-esm',
-      '/es-modules/package-type-module/imports-noext.mjs',
-      '/es-modules/package-type-module/extension.unknown',
-      '/es-modules/package-type-module/imports-unknownext.mjs',
-    ]
-  ) {
-    it('should throw', async () => {
-      const entry = fixtures.path(fixturePath);
-      const { code, signal, stderr, stdout } = await spawnPromisified(execPath, [entry]);
-
-      assert.strictEqual(code, 1);
-      assert.strictEqual(signal, null);
-      assert.strictEqual(stdout, '');
-      assert.ok(stderr.includes('ERR_UNKNOWN_FILE_EXTENSION'));
-      if (fixturePath.includes('noext')) {
-        // Check for explanation to users
-        assert.ok(stderr.includes('extensionless'));
-      }
-    });
-  }
-});
diff --git a/test/parallel/test-esm-no-extension.mjs b/test/parallel/test-esm-no-extension.mjs
new file mode 100644
index 00000000000000..047e124b3fd4e8
--- /dev/null
+++ b/test/parallel/test-esm-no-extension.mjs
@@ -0,0 +1,22 @@
+import * as common from '../common/index.mjs';
+import * as fixtures from '../common/fixtures.mjs';
+import { spawn } from 'node:child_process';
+import assert from 'node:assert';
+
+const entry = fixtures.path('/es-modules/package-type-module/noext-esm');
+
+// Run a module that does not have extension.
+// This is to ensure that "type": "module" applies to extensionless files.
+
+const child = spawn(process.execPath, [entry]);
+
+let stdout = '';
+child.stdout.setEncoding('utf8');
+child.stdout.on('data', (data) => {
+  stdout += data;
+});
+child.on('close', common.mustCall((code, signal) => {
+  assert.strictEqual(code, 0);
+  assert.strictEqual(signal, null);
+  assert.strictEqual(stdout, 'executed\n');
+}));
diff --git a/test/parallel/test-esm-unknown-main.mjs b/test/parallel/test-esm-unknown-main.mjs
new file mode 100644
index 00000000000000..d460393e19dbc0
--- /dev/null
+++ b/test/parallel/test-esm-unknown-main.mjs
@@ -0,0 +1,79 @@
+import * as common from '../common/index.mjs';
+import * as fixtures from '../common/fixtures.mjs';
+import { spawn } from 'node:child_process';
+import assert from 'node:assert';
+
+{
+  const entry = fixtures.path(
+    '/es-modules/package-type-module/extension.unknown'
+  );
+  const child = spawn(process.execPath, [entry]);
+  let stdout = '';
+  let stderr = '';
+  child.stderr.setEncoding('utf8');
+  child.stdout.setEncoding('utf8');
+  child.stdout.on('data', (data) => {
+    stdout += data;
+  });
+  child.stderr.on('data', (data) => {
+    stderr += data;
+  });
+  child.on('close', common.mustCall((code, signal) => {
+    assert.strictEqual(code, 1);
+    assert.strictEqual(signal, null);
+    assert.strictEqual(stdout, '');
+    assert.ok(stderr.indexOf('ERR_UNKNOWN_FILE_EXTENSION') !== -1);
+  }));
+}
+{
+  const entry = fixtures.path(
+    '/es-modules/package-type-module/imports-unknownext.mjs'
+  );
+  const child = spawn(process.execPath, [entry]);
+  let stdout = '';
+  let stderr = '';
+  child.stderr.setEncoding('utf8');
+  child.stdout.setEncoding('utf8');
+  child.stdout.on('data', (data) => {
+    stdout += data;
+  });
+  child.stderr.on('data', (data) => {
+    stderr += data;
+  });
+  child.on('close', common.mustCall((code, signal) => {
+    assert.strictEqual(code, 1);
+    assert.strictEqual(signal, null);
+    assert.strictEqual(stdout, '');
+    assert.ok(stderr.indexOf('ERR_UNKNOWN_FILE_EXTENSION') !== -1);
+  }));
+}
+{
+  const entry = fixtures.path('/es-modules/package-type-module/noext-esm');
+  const child = spawn(process.execPath, [entry]);
+  let stdout = '';
+  child.stdout.setEncoding('utf8');
+  child.stdout.on('data', (data) => {
+    stdout += data;
+  });
+  child.on('close', common.mustCall((code, signal) => {
+    assert.strictEqual(code, 0);
+    assert.strictEqual(signal, null);
+    assert.strictEqual(stdout, 'executed\n');
+  }));
+}
+{
+  const entry = fixtures.path(
+    '/es-modules/package-type-module/imports-noext.mjs'
+  );
+  const child = spawn(process.execPath, [entry]);
+  let stdout = '';
+  child.stdout.setEncoding('utf8');
+  child.stdout.on('data', (data) => {
+    stdout += data;
+  });
+  child.on('close', common.mustCall((code, signal) => {
+    assert.strictEqual(code, 0);
+    assert.strictEqual(signal, null);
+    assert.strictEqual(stdout, 'executed\n');
+  }));
+}