diff --git a/src/components/pages/AuthGateStep/AuthGateStep.stories.tsx b/src/components/pages/AuthGateStep/AuthGateStep.stories.tsx
new file mode 100644
index 0000000..952aa05
--- /dev/null
+++ b/src/components/pages/AuthGateStep/AuthGateStep.stories.tsx
@@ -0,0 +1,269 @@
+import { useState } from 'react';
+import type { Meta, StoryObj } from '@storybook/react';
+import { AuthGateStep } from './AuthGateStep';
+import type { AuthGateStepValues, AuthGateStepErrors } from './AuthGateStep';
+import { Navigation } from '../../organisms/Navigation';
+import Box from '@mui/material/Box';
+
+// ─── Helpers ─────────────────────────────────────────────────────────────────
+
+const FALogo = () => (
+  <Box sx={{ display: 'flex', alignItems: 'center' }}>
+    <Box
+      component="img"
+      src="/brandlogo/logo-full.svg"
+      alt="Funeral Arranger"
+      sx={{ height: 28, display: { xs: 'none', md: 'block' } }}
+    />
+    <Box
+      component="img"
+      src="/brandlogo/logo-short.svg"
+      alt="Funeral Arranger"
+      sx={{ height: 28, display: { xs: 'block', md: 'none' } }}
+    />
+  </Box>
+);
+
+const nav = (
+  <Navigation
+    logo={<FALogo />}
+    items={[
+      { label: 'FAQ', href: '/faq' },
+      { label: 'Contact Us', href: '/contact' },
+    ]}
+  />
+);
+
+const defaultValues: AuthGateStepValues = {
+  subStep: 'email',
+  email: '',
+  firstName: '',
+  lastName: '',
+  phone: '',
+  contactPreference: 'call_anytime',
+  verificationCode: '',
+};
+
+// ─── Meta ────────────────────────────────────────────────────────────────────
+
+const meta: Meta<typeof AuthGateStep> = {
+  title: 'Pages/AuthGateStep',
+  component: AuthGateStep,
+  tags: ['autodocs'],
+  parameters: {
+    layout: 'fullscreen',
+  },
+};
+
+export default meta;
+type Story = StoryObj<typeof AuthGateStep>;
+
+// ─── Interactive (default) ──────────────────────────────────────────────────
+
+/** Fully interactive — walk through all three sub-steps */
+export const Default: Story = {
+  render: () => {
+    const [values, setValues] = useState<AuthGateStepValues>({ ...defaultValues });
+    const [errors, setErrors] = useState<AuthGateStepErrors>({});
+
+    const handleContinue = () => {
+      const newErrors: AuthGateStepErrors = {};
+
+      if (values.subStep === 'email') {
+        if (!values.email || !/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(values.email)) {
+          newErrors.email =
+            "That email address doesn't look quite right. Please check it and try again.";
+        }
+        if (Object.keys(newErrors).length === 0) {
+          setValues((v) => ({ ...v, subStep: 'details' }));
+          setErrors({});
+          return;
+        }
+      }
+
+      if (values.subStep === 'details') {
+        if (!values.firstName) newErrors.firstName = 'We need your first name to save the plan.';
+        if (!values.lastName) newErrors.lastName = 'We need your last name to save the plan.';
+        if (values.contactPreference !== 'email_only' && !values.phone) {
+          newErrors.phone = 'Please enter a valid Australian phone number, like 0412 345 678.';
+        }
+        if (Object.keys(newErrors).length === 0) {
+          setValues((v) => ({ ...v, subStep: 'verify' }));
+          setErrors({});
+          return;
+        }
+      }
+
+      if (values.subStep === 'verify') {
+        if (!values.verificationCode || values.verificationCode.length !== 6) {
+          newErrors.verificationCode =
+            "That code doesn't match. Please check the email we sent and try again.";
+        }
+        if (Object.keys(newErrors).length === 0) {
+          alert(`Authenticated: ${values.firstName} ${values.lastName} (${values.email})`);
+          return;
+        }
+      }
+
+      setErrors(newErrors);
+    };
+
+    return (
+      <AuthGateStep
+        values={values}
+        onChange={(v) => {
+          setValues(v);
+          setErrors({});
+        }}
+        onContinue={handleContinue}
+        onBack={() => alert('Back to preview')}
+        onGoogleSSO={() => alert('Google SSO')}
+        onMicrosoftSSO={() => alert('Microsoft SSO')}
+        errors={errors}
+        navigation={nav}
+      />
+    );
+  },
+};
+
+// ─── Sub-step 2: Details ────────────────────────────────────────────────────
+
+/** Details sub-step — email entered, name/phone fields revealed */
+export const DetailsSubStep: Story = {
+  render: () => {
+    const [values, setValues] = useState<AuthGateStepValues>({
+      ...defaultValues,
+      subStep: 'details',
+      email: 'jane@example.com',
+    });
+    return (
+      <AuthGateStep
+        values={values}
+        onChange={setValues}
+        onContinue={() => setValues((v) => ({ ...v, subStep: 'verify' }))}
+        onBack={() => alert('Back')}
+        navigation={nav}
+      />
+    );
+  },
+};
+
+// ─── Sub-step 3: Verification ───────────────────────────────────────────────
+
+/** Verification sub-step — code entry */
+export const VerifySubStep: Story = {
+  render: () => {
+    const [values, setValues] = useState<AuthGateStepValues>({
+      ...defaultValues,
+      subStep: 'verify',
+      email: 'jane@example.com',
+      firstName: 'Jane',
+      lastName: 'Smith',
+      phone: '0412 345 678',
+    });
+    return (
+      <AuthGateStep
+        values={values}
+        onChange={setValues}
+        onContinue={() => alert('Verified!')}
+        onBack={() => alert('Back')}
+        navigation={nav}
+      />
+    );
+  },
+};
+
+// ─── At-need variant ────────────────────────────────────────────────────────
+
+/** At-need subheading copy variant */
+export const AtNeed: Story = {
+  render: () => {
+    const [values, setValues] = useState<AuthGateStepValues>({ ...defaultValues });
+    return (
+      <AuthGateStep
+        values={values}
+        onChange={setValues}
+        onContinue={() => setValues((v) => ({ ...v, subStep: 'details' }))}
+        onBack={() => alert('Back')}
+        isAtNeed
+        navigation={nav}
+      />
+    );
+  },
+};
+
+// ─── Email-only preference ──────────────────────────────────────────────────
+
+/** Phone becomes optional when contact preference is email-only */
+export const EmailOnlyPreference: Story = {
+  render: () => {
+    const [values, setValues] = useState<AuthGateStepValues>({
+      ...defaultValues,
+      subStep: 'details',
+      email: 'jane@example.com',
+      contactPreference: 'email_only',
+    });
+    return (
+      <AuthGateStep
+        values={values}
+        onChange={setValues}
+        onContinue={() => setValues((v) => ({ ...v, subStep: 'verify' }))}
+        onBack={() => alert('Back')}
+        navigation={nav}
+      />
+    );
+  },
+};
+
+// ─── Validation errors ──────────────────────────────────────────────────────
+
+/** Details sub-step with all validation errors showing */
+export const WithErrors: Story = {
+  render: () => {
+    const [values, setValues] = useState<AuthGateStepValues>({
+      ...defaultValues,
+      subStep: 'details',
+      email: 'jane@example.com',
+    });
+    return (
+      <AuthGateStep
+        values={values}
+        onChange={setValues}
+        onContinue={() => {}}
+        errors={{
+          firstName: 'We need your first name to save the plan.',
+          lastName: 'We need your last name to save the plan.',
+          phone: 'Please enter a valid Australian phone number, like 0412 345 678.',
+        }}
+        onBack={() => alert('Back')}
+        navigation={nav}
+      />
+    );
+  },
+};
+
+// ─── Loading state ──────────────────────────────────────────────────────────
+
+/** Continue button in loading state */
+export const Loading: Story = {
+  render: () => {
+    const [values, setValues] = useState<AuthGateStepValues>({
+      ...defaultValues,
+      subStep: 'verify',
+      email: 'jane@example.com',
+      firstName: 'Jane',
+      lastName: 'Smith',
+      phone: '0412 345 678',
+      verificationCode: '123456',
+    });
+    return (
+      <AuthGateStep
+        values={values}
+        onChange={setValues}
+        onContinue={() => {}}
+        loading
+        navigation={nav}
+      />
+    );
+  },
+};
diff --git a/src/components/pages/AuthGateStep/AuthGateStep.tsx b/src/components/pages/AuthGateStep/AuthGateStep.tsx
new file mode 100644
index 0000000..c7633fb
--- /dev/null
+++ b/src/components/pages/AuthGateStep/AuthGateStep.tsx
@@ -0,0 +1,336 @@
+import React from 'react';
+import Box from '@mui/material/Box';
+import TextField from '@mui/material/TextField';
+import MenuItem from '@mui/material/MenuItem';
+import type { SxProps, Theme } from '@mui/material/styles';
+import GoogleIcon from '@mui/icons-material/Google';
+import MicrosoftIcon from '@mui/icons-material/Window';
+import { WizardLayout } from '../../templates/WizardLayout';
+import { Collapse } from '../../atoms/Collapse';
+import { Typography } from '../../atoms/Typography';
+import { Button } from '../../atoms/Button';
+import { Divider } from '../../atoms/Divider';
+
+// ─── Types ───────────────────────────────────────────────────────────────────
+
+/** Which sub-step of the auth flow the user is on */
+export type AuthSubStep = 'email' | 'details' | 'verify';
+
+/** Contact preference options */
+export type ContactPreference = 'call_anytime' | 'email_preferred' | 'email_only';
+
+/** Form values for the auth gate step */
+export interface AuthGateStepValues {
+  /** Current sub-step */
+  subStep: AuthSubStep;
+  /** Email address */
+  email: string;
+  /** First name */
+  firstName: string;
+  /** Last name */
+  lastName: string;
+  /** Phone number */
+  phone: string;
+  /** Contact preference */
+  contactPreference: ContactPreference;
+  /** Email verification code */
+  verificationCode: string;
+}
+
+/** Field-level error messages */
+export interface AuthGateStepErrors {
+  email?: string;
+  firstName?: string;
+  lastName?: string;
+  phone?: string;
+  verificationCode?: string;
+}
+
+/** Props for the AuthGateStep page component */
+export interface AuthGateStepProps {
+  /** Current form values */
+  values: AuthGateStepValues;
+  /** Callback when any field value changes */
+  onChange: (values: AuthGateStepValues) => void;
+  /** Callback when the Continue button is clicked */
+  onContinue: () => void;
+  /** Callback for back navigation */
+  onBack?: () => void;
+  /** Callback for Google SSO */
+  onGoogleSSO?: () => void;
+  /** Callback for Microsoft SSO */
+  onMicrosoftSSO?: () => void;
+  /** Field-level validation errors */
+  errors?: AuthGateStepErrors;
+  /** Whether the Continue button is in a loading state */
+  loading?: boolean;
+  /** Whether the user is arranging at-need (vs pre-planning) */
+  isAtNeed?: boolean;
+  /** Navigation bar — passed through to WizardLayout */
+  navigation?: React.ReactNode;
+  /** Hide the help bar */
+  hideHelpBar?: boolean;
+  /** MUI sx prop for the root */
+  sx?: SxProps<Theme>;
+}
+
+// ─── Copy helpers ────────────────────────────────────────────────────────────
+
+function getSubheading(isAtNeed: boolean): string {
+  if (isAtNeed) {
+    return 'We need a few details so a funeral arranger can help you with the next steps.';
+  }
+  return 'Save your plan to return and update it anytime.';
+}
+
+function getCTALabel(subStep: AuthSubStep): string {
+  switch (subStep) {
+    case 'email':
+      return 'Continue with email';
+    case 'details':
+      return 'Continue';
+    case 'verify':
+      return 'Verify and continue';
+  }
+}
+
+// ─── Component ───────────────────────────────────────────────────────────────
+
+/**
+ * Step 5 — Auth Gate for the FA arrangement wizard.
+ *
+ * Registration/login step positioned after preview (step 4). Users have
+ * already seen packages with pricing before being asked to register.
+ * Framed as a benefit ("Save your plan") not a gate.
+ *
+ * Three sub-steps with progressive disclosure:
+ * 1. SSO buttons + email entry
+ * 2. Name, phone, contact preference (after email)
+ * 3. Verification code (after details)
+ *
+ * Phone becomes optional when contactPreference is "email_only".
+ *
+ * Pure presentation component — props in, callbacks out.
+ *
+ * Spec: documentation/steps/steps/05_auth_gate.yaml
+ */
+export const AuthGateStep: React.FC<AuthGateStepProps> = ({
+  values,
+  onChange,
+  onContinue,
+  onBack,
+  onGoogleSSO,
+  onMicrosoftSSO,
+  errors,
+  loading = false,
+  isAtNeed = false,
+  navigation,
+  hideHelpBar,
+  sx,
+}) => {
+  const isEmailOnly = values.contactPreference === 'email_only';
+
+  const handleFieldChange = (field: keyof AuthGateStepValues, value: string) => {
+    onChange({ ...values, [field]: value });
+  };
+
+  return (
+    <WizardLayout
+      variant="centered-form"
+      navigation={navigation}
+      showBackLink={!!onBack}
+      backLabel="Back"
+      onBack={onBack}
+      hideHelpBar={hideHelpBar}
+      sx={sx}
+    >
+      {/* Page heading */}
+      <Typography variant="display3" component="h1" sx={{ mb: 1 }} tabIndex={-1}>
+        Save your plan
+      </Typography>
+
+      <Typography variant="body1" color="text.secondary" sx={{ mb: 5 }} aria-live="polite">
+        {getSubheading(isAtNeed)}
+      </Typography>
+
+      <Box
+        component="form"
+        noValidate
+        onSubmit={(e: React.FormEvent) => {
+          e.preventDefault();
+          onContinue();
+        }}
+      >
+        {/* ─── Sub-step 1: SSO + Email ─── */}
+        <Box
+          sx={{ display: 'flex', flexDirection: 'column', gap: 1.5, mb: 3 }}
+          role="group"
+          aria-label="Sign in options"
+        >
+          <Button
+            variant="outlined"
+            color="secondary"
+            size="large"
+            fullWidth
+            startIcon={<GoogleIcon />}
+            onClick={onGoogleSSO}
+            type="button"
+          >
+            Continue with Google
+          </Button>
+          <Button
+            variant="outlined"
+            color="secondary"
+            size="large"
+            fullWidth
+            startIcon={<MicrosoftIcon />}
+            onClick={onMicrosoftSSO}
+            type="button"
+          >
+            Continue with Microsoft
+          </Button>
+        </Box>
+
+        <Divider sx={{ my: 3 }}>
+          <Typography variant="body2" color="text.secondary">
+            or
+          </Typography>
+        </Divider>
+
+        <TextField
+          label="Your email address"
+          type="email"
+          value={values.email}
+          onChange={(e) => handleFieldChange('email', e.target.value)}
+          error={!!errors?.email}
+          helperText={errors?.email}
+          placeholder="you@example.com"
+          autoComplete="email"
+          inputMode="email"
+          fullWidth
+          required
+          disabled={values.subStep !== 'email'}
+          sx={{ mb: 3 }}
+        />
+
+        {/* ─── Sub-step 2: Details (after email) ─── */}
+        <Collapse in={values.subStep === 'details' || values.subStep === 'verify'}>
+          <Box
+            sx={{ display: 'flex', flexDirection: 'column', gap: 2.5, mb: 3 }}
+            role="group"
+            aria-label="Your details"
+          >
+            <Typography variant="labelLg" component="h2" sx={{ mb: 0.5 }}>
+              A few details to save your plan
+            </Typography>
+
+            <Box sx={{ display: 'flex', flexDirection: { xs: 'column', sm: 'row' }, gap: 2 }}>
+              <TextField
+                label="First name"
+                value={values.firstName}
+                onChange={(e) => handleFieldChange('firstName', e.target.value)}
+                error={!!errors?.firstName}
+                helperText={errors?.firstName}
+                autoComplete="given-name"
+                fullWidth
+                required
+                disabled={values.subStep === 'verify'}
+              />
+              <TextField
+                label="Last name"
+                value={values.lastName}
+                onChange={(e) => handleFieldChange('lastName', e.target.value)}
+                error={!!errors?.lastName}
+                helperText={errors?.lastName}
+                autoComplete="family-name"
+                fullWidth
+                required
+                disabled={values.subStep === 'verify'}
+              />
+            </Box>
+
+            <TextField
+              label={isEmailOnly ? 'Phone (optional)' : 'Best number to reach you'}
+              type="tel"
+              value={values.phone}
+              onChange={(e) => handleFieldChange('phone', e.target.value)}
+              error={!!errors?.phone}
+              helperText={errors?.phone}
+              placeholder="e.g. 0412 345 678"
+              autoComplete="tel"
+              inputMode="tel"
+              fullWidth
+              required={!isEmailOnly}
+              disabled={values.subStep === 'verify'}
+            />
+
+            <TextField
+              select
+              label="Contact preference"
+              value={values.contactPreference}
+              onChange={(e) => handleFieldChange('contactPreference', e.target.value)}
+              fullWidth
+              disabled={values.subStep === 'verify'}
+            >
+              <MenuItem value="call_anytime">Call me anytime</MenuItem>
+              <MenuItem value="email_preferred">Email is preferred</MenuItem>
+              <MenuItem value="email_only">Only contact by email</MenuItem>
+            </TextField>
+          </Box>
+        </Collapse>
+
+        {/* ─── Sub-step 3: Verification code ─── */}
+        <Collapse in={values.subStep === 'verify'}>
+          <Box sx={{ mb: 3 }} role="group" aria-label="Email verification">
+            <Typography variant="body2" color="text.secondary" sx={{ mb: 2 }}>
+              We&apos;ve sent a 6-digit code to <strong>{values.email}</strong>. Please enter it
+              below.
+            </Typography>
+
+            <TextField
+              label="Verification code"
+              value={values.verificationCode}
+              onChange={(e) => handleFieldChange('verificationCode', e.target.value)}
+              error={!!errors?.verificationCode}
+              helperText={errors?.verificationCode || 'Check your email for the 6-digit code'}
+              placeholder="Enter 6-digit code"
+              autoComplete="one-time-code"
+              inputMode="numeric"
+              fullWidth
+              required
+            />
+          </Box>
+        </Collapse>
+
+        {/* Terms */}
+        <Typography variant="caption" color="text.secondary" sx={{ display: 'block', mb: 3 }}>
+          By continuing, you agree to the{' '}
+          <Box
+            component="a"
+            href="#"
+            sx={{
+              color: 'var(--fa-color-text-brand)',
+              textDecoration: 'underline',
+              fontSize: 'inherit',
+            }}
+          >
+            terms and conditions
+          </Box>
+          .
+        </Typography>
+
+        <Divider sx={{ my: 3 }} />
+
+        {/* CTA */}
+        <Box sx={{ display: 'flex', justifyContent: 'flex-end' }}>
+          <Button type="submit" variant="contained" size="large" loading={loading}>
+            {getCTALabel(values.subStep)}
+          </Button>
+        </Box>
+      </Box>
+    </WizardLayout>
+  );
+};
+
+AuthGateStep.displayName = 'AuthGateStep';
+export default AuthGateStep;
diff --git a/src/components/pages/AuthGateStep/index.ts b/src/components/pages/AuthGateStep/index.ts
new file mode 100644
index 0000000..66193b8
--- /dev/null
+++ b/src/components/pages/AuthGateStep/index.ts
@@ -0,0 +1,8 @@
+export { AuthGateStep, default } from './AuthGateStep';
+export type {
+  AuthGateStepProps,
+  AuthGateStepValues,
+  AuthGateStepErrors,
+  AuthSubStep,
+  ContactPreference,
+} from './AuthGateStep';