diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index cbd3ddd..e94d53d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -33,6 +33,13 @@ jobs:
           version: "1.71.0"
       - run: sam --version | grep -F 1.71.0
 
+      - name: Test official installer (pinned version; should use cache)
+        uses: ./
+        with:
+          use-installer: true
+          version: "1.71.0"
+      - run: sam --version | grep -F 1.71.0
+
       - name: Test official installer (latest version)
         uses: ./
         with:
diff --git a/dist/index.js b/dist/index.js
index 1bb769f..d59b1bf 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -131,6 +131,13 @@ function getInput(name, pattern, defaultValue) {
   return value;
 }
 
+/**
+ * Returns whether a string is in the format x.y.z.
+ */
+function isSemver(s) {
+  return /^\d+\.\d+\.\d+$/.test(s);
+}
+
 /**
  * Installs SAM CLI using the native installers.
  *
@@ -140,13 +147,27 @@ function getInput(name, pattern, defaultValue) {
  * @returns {Promise<string>} The directory SAM CLI is installed in.
  */
 // TODO: Support more platforms
-// TODO: Support caching
 async function installUsingNativeInstaller(version) {
   if (os.platform() !== "linux" || os.arch() !== "x64") {
     core.setFailed("Only Linux x86-64 is supported with use-installer: true");
     return "";
   }
 
+  // Must be full semantic version; downloads version directly from GitHub
+  if (version && !isSemver(version)) {
+    core.setFailed("Version must be in the format x.y.z");
+    return "";
+  }
+
+  // TODO: If not set, check latest version and return from cache if exists
+  if (version) {
+    const cachedDir = tc.find("sam", version);
+    if (cachedDir) {
+      core.info(`Using cached AWS SAM CLI ${version} from ${cachedDir}`);
+      return path.join(cachedDir, "dist");
+    }
+  }
+
   const url = version
     ? `https://github.com/aws/aws-sam-cli/releases/download/v${version}/aws-sam-cli-linux-x86_64.zip`
     : "https://github.com/aws/aws-sam-cli/releases/latest/download/aws-sam-cli-linux-x86_64.zip";
@@ -155,6 +176,13 @@ async function installUsingNativeInstaller(version) {
   const extractedDir = await tc.extractZip(toolPath);
   const binDir = path.join(extractedDir, "dist");
 
+  // TODO: If not set, cache with latest version
+  if (version) {
+    const cachedDir = await tc.cacheDir(extractedDir, "sam", version);
+    core.info(`Cached AWS SAM CLI ${version} to ${cachedDir}`);
+    return path.join(cachedDir, "dist");
+  }
+
   return binDir;
 }
 
diff --git a/lib/setup.js b/lib/setup.js
index 018ecd9..f099fdf 100644
--- a/lib/setup.js
+++ b/lib/setup.js
@@ -106,6 +106,13 @@ function getInput(name, pattern, defaultValue) {
   return value;
 }
 
+/**
+ * Returns whether a string is in the format x.y.z.
+ */
+function isSemver(s) {
+  return /^\d+\.\d+\.\d+$/.test(s);
+}
+
 /**
  * Installs SAM CLI using the native installers.
  *
@@ -115,13 +122,27 @@ function getInput(name, pattern, defaultValue) {
  * @returns {Promise<string>} The directory SAM CLI is installed in.
  */
 // TODO: Support more platforms
-// TODO: Support caching
 async function installUsingNativeInstaller(version) {
   if (os.platform() !== "linux" || os.arch() !== "x64") {
     core.setFailed("Only Linux x86-64 is supported with use-installer: true");
     return "";
   }
 
+  // Must be full semantic version; downloads version directly from GitHub
+  if (version && !isSemver(version)) {
+    core.setFailed("Version must be in the format x.y.z");
+    return "";
+  }
+
+  // TODO: If not set, check latest version and return from cache if exists
+  if (version) {
+    const cachedDir = tc.find("sam", version);
+    if (cachedDir) {
+      core.info(`Using cached AWS SAM CLI ${version} from ${cachedDir}`);
+      return path.join(cachedDir, "dist");
+    }
+  }
+
   const url = version
     ? `https://github.com/aws/aws-sam-cli/releases/download/v${version}/aws-sam-cli-linux-x86_64.zip`
     : "https://github.com/aws/aws-sam-cli/releases/latest/download/aws-sam-cli-linux-x86_64.zip";
@@ -130,6 +151,13 @@ async function installUsingNativeInstaller(version) {
   const extractedDir = await tc.extractZip(toolPath);
   const binDir = path.join(extractedDir, "dist");
 
+  // TODO: If not set, cache with latest version
+  if (version) {
+    const cachedDir = await tc.cacheDir(extractedDir, "sam", version);
+    core.info(`Cached AWS SAM CLI ${version} to ${cachedDir}`);
+    return path.join(cachedDir, "dist");
+  }
+
   return binDir;
 }
 
diff --git a/test/setup.test.js b/test/setup.test.js
index 0073ee8..7ecb212 100644
--- a/test/setup.test.js
+++ b/test/setup.test.js
@@ -1,12 +1,14 @@
 jest.mock("@actions/core");
 jest.mock("@actions/exec");
 jest.mock("@actions/io");
+jest.mock("@actions/tool-cache");
 
 const os = require("os");
 
 const core = require("@actions/core");
 const exec = require("@actions/exec");
 const io = require("@actions/io");
+const tc = require("@actions/tool-cache");
 
 const setup = require("../lib/setup");
 
@@ -82,3 +84,79 @@ test.each([
     .mockReturnValueOnce(input.python);
   await expect(setup).rejects.toThrow(Error);
 });
+
+test("when use-installer enabled and version specified and cached version exists, uses cached version", async () => {
+  jest.spyOn(os, "platform").mockReturnValue("linux");
+  jest.spyOn(os, "arch").mockReturnValue("x64");
+
+  core.getBooleanInput = jest.fn().mockReturnValue(true);
+  core.getInput = jest.fn().mockReturnValueOnce("1.23.456");
+
+  tc.find = jest.fn().mockReturnValueOnce("/path/to/cached/sam");
+
+  await setup();
+
+  expect(tc.find).toHaveBeenCalledTimes(1);
+  expect(tc.cacheDir).toHaveBeenCalledTimes(0);
+
+  // Must be cached path
+  expect(core.addPath).toHaveBeenCalledWith("/path/to/cached/sam/dist");
+});
+
+test("when use-installer enabled and version specified and cached version does not exist, downloads and caches version", async () => {
+  jest.spyOn(os, "platform").mockReturnValue("linux");
+  jest.spyOn(os, "arch").mockReturnValue("x64");
+
+  core.getBooleanInput = jest.fn().mockReturnValue(true);
+  core.getInput = jest.fn().mockReturnValueOnce("1.23.456");
+
+  tc.find = jest.fn().mockReturnValueOnce("");
+  tc.extractZip = jest.fn().mockReturnValueOnce("/path/to/extracted/sam");
+  tc.cacheDir = jest.fn().mockReturnValueOnce("/path/to/cached/sam");
+
+  await setup();
+
+  expect(tc.find).toHaveBeenCalledTimes(1);
+  expect(tc.cacheDir).toHaveBeenCalledTimes(1);
+
+  // Must return cached path
+  expect(core.addPath).toHaveBeenCalledWith("/path/to/cached/sam/dist");
+});
+
+test("when use-installer enabled and version not specified, downloads latest version (Linux x64)", async () => {
+  jest.spyOn(os, "platform").mockReturnValue("linux");
+  jest.spyOn(os, "arch").mockReturnValue("x64");
+
+  core.getBooleanInput = jest.fn().mockReturnValue(true);
+  core.getInput = jest.fn().mockReturnValueOnce("");
+
+  tc.find = jest.fn().mockReturnValueOnce("");
+  tc.extractZip = jest.fn().mockReturnValueOnce("/path/to/extracted/sam");
+  tc.cacheDir = jest.fn().mockReturnValueOnce("/path/to/cached/sam");
+  tc.downloadTool = jest.fn().mockReturnValueOnce("/path/to/downloaded/sam");
+
+  await setup();
+
+  expect(tc.downloadTool).toHaveBeenCalledWith(
+    "https://github.com/aws/aws-sam-cli/releases/latest/download/aws-sam-cli-linux-x86_64.zip"
+  );
+
+  // Currently no caching on latest
+  expect(tc.find).toHaveBeenCalledTimes(0);
+  expect(tc.cacheDir).toHaveBeenCalledTimes(0);
+  expect(core.addPath).toHaveBeenCalledWith("/path/to/extracted/sam/dist");
+});
+
+test("when use-installer enabled but version is not in format x.y.z, not downloaded or checked in cache", async () => {
+  jest.spyOn(os, "platform").mockReturnValue("linux");
+  jest.spyOn(os, "arch").mockReturnValue("x64");
+
+  core.getBooleanInput = jest.fn().mockReturnValue(true);
+
+  for (const version of ["1.2", "1.*", "3"]) {
+    core.getInput = jest.fn().mockReturnValueOnce(version);
+    await setup();
+    expect(tc.downloadTool).toHaveBeenCalledTimes(0);
+    expect(tc.find).toHaveBeenCalledTimes(0);
+  }
+});