diff --git a/src/components/wizard/StepIndicator.test.tsx b/src/components/wizard/StepIndicator.test.tsx
index 2d1d9b4..d5dcacb 100644
--- a/src/components/wizard/StepIndicator.test.tsx
+++ b/src/components/wizard/StepIndicator.test.tsx
@@ -1,27 +1,226 @@
 // @vitest-environment jsdom
 // Covers WIZD-03: going back preserves remote.params; deployment options are untouched
-import { describe, it, expect } from 'vitest';
+import { describe, it, expect, vi } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import React from 'react';
+import { StepIndicator } from './StepIndicator';
+import { WizardProvider } from '../../store/context';
+import { useWizard } from '../../store/context';
+
+// Helper: renders StepIndicator with a given currentStep by navigating the wizard state
+function renderWithStep(currentStep: number) {
+  // We need a wrapper that sets the step before rendering StepIndicator
+  function Wrapper() {
+    const { dispatch } = useWizard();
+    React.useEffect(() => {
+      if (currentStep > 0) {
+        dispatch({ type: 'SET_STEP', payload: currentStep });
+      }
+    }, [dispatch]);
+    return <StepIndicator />;
+  }
+
+  return render(
+    <WizardProvider>
+      <Wrapper />
+    </WizardProvider>
+  );
+}
+
+// Helper: renders StepIndicator with a spy dispatch
+function renderWithDispatchSpy(currentStep: number) {
+  const dispatched: { type: string; payload?: unknown }[] = [];
+
+  function SpyWrapper() {
+    const { dispatch, state } = useWizard();
+    React.useEffect(() => {
+      if (currentStep > 0) {
+        dispatch({ type: 'SET_STEP', payload: currentStep });
+      }
+    }, [dispatch]);
+
+    // Wrap dispatch to spy on calls after initial setup
+    const spyDispatch = React.useCallback(
+      (action: { type: string; payload?: unknown }) => {
+        dispatched.push(action);
+        dispatch(action as Parameters<typeof dispatch>[0]);
+      },
+      [dispatch]
+    );
+
+    return (
+      <div>
+        <span data-testid="current-step">{state.currentStep}</span>
+        <StepIndicatorWithDispatch dispatch={spyDispatch} />
+      </div>
+    );
+  }
+
+  // We'll test dispatch behavior by checking actual state changes instead
+  return { dispatched, ...render(<WizardProvider><SpyWrapper /></WizardProvider>) };
+}
+
+// A version of StepIndicator that accepts an optional dispatch override for testing
+// Actually we'll just test via rendered output and state changes
 
 describe('StepIndicator', () => {
   describe('WIZD-03: back navigation preserves state', () => {
-    it('clicking a completed step dispatches SET_STEP', () => {
-      expect.fail('not yet implemented');
+    it('step 0 shows as active when currentStep is 0', async () => {
+      render(
+        <WizardProvider>
+          <StepIndicator />
+        </WizardProvider>
+      );
+      // Step 0 (Backend) should be the active step — rendered as bold/active span
+      const backendLabel = screen.getByText(/Backend/);
+      expect(backendLabel).toBeDefined();
     });
 
-    it('clicking back to step 0 dispatches SET_REMOTE_PARAMS({}) to clear params', () => {
-      expect.fail('not yet implemented');
+    it('completed steps are clickable', async () => {
+      // Render with currentStep=2 so steps 0 and 1 are completed
+      function Wrapper() {
+        const { dispatch } = useWizard();
+        React.useEffect(() => {
+          dispatch({ type: 'SET_STEP', payload: 2 });
+        }, [dispatch]);
+        return <StepIndicator />;
+      }
+
+      render(
+        <WizardProvider>
+          <Wrapper />
+        </WizardProvider>
+      );
+
+      // Wait for useEffect to set step to 2
+      await screen.findByText(/Deployment/);
+
+      // Steps 0 and 1 should be clickable buttons
+      const buttons = screen.getAllByRole('button');
+      // Should have at least 2 buttons for step 0 and step 1
+      expect(buttons.length).toBeGreaterThanOrEqual(2);
     });
 
-    it('clicking back to step 0 does NOT dispatch RESET (deployment preserved)', () => {
-      expect.fail('not yet implemented');
+    it('clicking a completed step dispatches SET_STEP', async () => {
+      const user = userEvent.setup();
+
+      function Wrapper() {
+        const { dispatch, state } = useWizard();
+        React.useEffect(() => {
+          dispatch({ type: 'SET_STEP', payload: 2 });
+        }, [dispatch]);
+        return (
+          <>
+            <span data-testid="step">{state.currentStep}</span>
+            <StepIndicator />
+          </>
+        );
+      }
+
+      render(
+        <WizardProvider>
+          <Wrapper />
+        </WizardProvider>
+      );
+
+      // Wait until currentStep is 2
+      await screen.findByText('2', { selector: '[data-testid="step"]' });
+
+      // Click the "Backend" step (step 0 — completed)
+      const buttons = screen.getAllByRole('button');
+      const backendButton = buttons.find((b) => b.textContent?.includes('Backend'));
+      expect(backendButton).toBeDefined();
+      await user.click(backendButton!);
+
+      // After clicking, currentStep should be 0
+      const stepEl = screen.getByTestId('step');
+      expect(stepEl.textContent).toBe('0');
     });
 
-    it('step 0 shows as active when currentStep is 0', () => {
-      expect.fail('not yet implemented');
+    it('clicking back to step 0 dispatches SET_REMOTE_PARAMS({}) to clear params', async () => {
+      const user = userEvent.setup();
+
+      function Wrapper() {
+        const { dispatch, state } = useWizard();
+        React.useEffect(() => {
+          dispatch({ type: 'SET_BACKEND_TYPE', payload: 'azureblob' });
+          dispatch({ type: 'SET_REMOTE_PARAMS', payload: { account: 'myaccount' } });
+          dispatch({ type: 'SET_STEP', payload: 2 });
+        }, [dispatch]);
+        return (
+          <>
+            <span data-testid="params">{JSON.stringify(state.remote.params)}</span>
+            <StepIndicator />
+          </>
+        );
+      }
+
+      render(
+        <WizardProvider>
+          <Wrapper />
+        </WizardProvider>
+      );
+
+      // Wait until step is 2 and params are set
+      await screen.findByText((text) => text.includes('myaccount'), { selector: '[data-testid="params"]' });
+
+      // Click the "Backend" step (step 0)
+      const buttons = screen.getAllByRole('button');
+      const backendButton = buttons.find((b) => b.textContent?.includes('Backend'));
+      expect(backendButton).toBeDefined();
+      await user.click(backendButton!);
+
+      // params should be cleared
+      const paramsEl = screen.getByTestId('params');
+      expect(paramsEl.textContent).toBe('{}');
     });
 
-    it('completed steps are clickable', () => {
-      expect.fail('not yet implemented');
+    it('clicking back to step 0 does NOT dispatch RESET (deployment preserved)', async () => {
+      const user = userEvent.setup();
+
+      function Wrapper() {
+        const { dispatch, state } = useWizard();
+        React.useEffect(() => {
+          // Set a non-default deployment state
+          dispatch({ type: 'SET_DEPLOYMENT', payload: { includeInstall: true } });
+          dispatch({ type: 'SET_DEPLOYMENT', payload: { scriptTargets: ['intune'] } });
+          dispatch({ type: 'SET_STEP', payload: 2 });
+        }, [dispatch]);
+        return (
+          <>
+            <span data-testid="include-install">{String(state.deployment.includeInstall)}</span>
+            <span data-testid="targets">{JSON.stringify(state.deployment.scriptTargets)}</span>
+            <StepIndicator />
+          </>
+        );
+      }
+
+      render(
+        <WizardProvider>
+          <Wrapper />
+        </WizardProvider>
+      );
+
+      // Wait until deployment state is customized and step is 2
+      await screen.findByText('true', { selector: '[data-testid="include-install"]' });
+
+      // Click the "Backend" step
+      const buttons = screen.getAllByRole('button');
+      const backendButton = buttons.find((b) => b.textContent?.includes('Backend'));
+      expect(backendButton).toBeDefined();
+      await user.click(backendButton!);
+
+      // Deployment options should be preserved (not reset)
+      const includeInstallEl = screen.getByTestId('include-install');
+      expect(includeInstallEl.textContent).toBe('true');
+      const targetsEl = screen.getByTestId('targets');
+      expect(targetsEl.textContent).toBe('["intune"]');
     });
   });
 });
+
+// Placeholder type for the spy component — not actually used in tests
+function StepIndicatorWithDispatch(_props: { dispatch: (action: { type: string; payload?: unknown }) => void }) {
+  return null;
+}