diff --git a/DB_SCHEMA_MAP.md b/DB_SCHEMA_MAP.md
index d24eb8c..6a6f79f 100644
--- a/DB_SCHEMA_MAP.md
+++ b/DB_SCHEMA_MAP.md
@@ -392,6 +392,7 @@ Default channels created by trigger on space INSERT: `general`, `announcements`,
 | 013 | Added `space_members.last_paid_at` timestamptz — required by importMembers and linkPaymentToMember |
 | 014-025 | See `docs/DATABASE_SCHEMA.md` migrations table (governance kernel, areas, forum/tiers/roles/invites, onboarding, permissions/ACLs, self-change hardening, incidents_insert re-assert) |
 | 026 | `forms`, `form_submissions` + `forms.manage` permission (additive, default-deny RLS; submissions immutable + service-client-only) |
+| 027 | `space_onboarding_steps.step_type` CHECK adds `'form'` (onboarding can embed a form/waiver; form id in step `config.form_id`) |
 
 ---
 
diff --git a/__tests__/forms.test.ts b/__tests__/forms.test.ts
index c860ad9..20d94ed 100644
--- a/__tests__/forms.test.ts
+++ b/__tests__/forms.test.ts
@@ -5,6 +5,8 @@ import {
   submitFormSchema,
   formSchemaArray,
   formFieldSchema,
+  onboardingStepTypeSchema,
+  createOnboardingStepSchema,
 } from '@/lib/validations'
 import { parseFormSchema, validateAnswers, type FormField } from '@/lib/forms-schema'
 
@@ -110,6 +112,23 @@ describe('validateAnswers', () => {
   })
 })
 
+describe('onboarding form step (Phase 4)', () => {
+  it('onboardingStepTypeSchema accepts "form" and rejects unknown', () => {
+    expect(onboardingStepTypeSchema.safeParse('form').success).toBe(true)
+    expect(onboardingStepTypeSchema.safeParse('content').success).toBe(true)
+    expect(onboardingStepTypeSchema.safeParse('quiz').success).toBe(false)
+  })
+
+  it('createOnboardingStepSchema accepts a form step with a form_id config', () => {
+    const r = createOnboardingStepSchema.safeParse({
+      step_type: 'form',
+      title: 'Sign the liability waiver',
+      config: { form_id: '11111111-1111-1111-1111-111111111111' },
+    })
+    expect(r.success).toBe(true)
+  })
+})
+
 describe('parseFormSchema', () => {
   it('returns [] for malformed stored schema', () => {
     expect(parseFormSchema('not an array')).toEqual([])
diff --git a/app/(app)/customize/customize-client.tsx b/app/(app)/customize/customize-client.tsx
index cbdcb5f..0bed4e5 100644
--- a/app/(app)/customize/customize-client.tsx
+++ b/app/(app)/customize/customize-client.tsx
@@ -8,7 +8,7 @@ import { AreasPanel } from './panels/areas-panel'
 import { AreaLeadsPanel } from './panels/area-leads-panel'
 import { InvitesPanel } from './panels/invites-panel'
 import { OnboardingPanel } from './panels/onboarding-panel'
-import type { RoleLabelRow, CustomRole, Tier, Invite, Step, Area } from './panels/types'
+import type { RoleLabelRow, CustomRole, Tier, Invite, Step, Area, FormOption } from './panels/types'
 
 type Section = 'roles' | 'permissions' | 'tiers' | 'areas' | 'area-leads' | 'invites' | 'onboarding'
 
@@ -38,6 +38,7 @@ interface Props {
   tiers: Tier[]
   invites: Invite[]
   onboardingSteps: Step[]
+  forms: FormOption[]
   areas: Area[]
   rolePerms: Array<{ subject: string; permission: string }>
   areaLeads: AreaLead[]
@@ -78,7 +79,7 @@ export function CustomizeClient(props: Props) {
           {section === 'areas' && <AreasPanel isAdmin={props.isAdmin} areas={props.areas} />}
           {section === 'area-leads' && <AreaLeadsPanel isAdmin={props.isAdmin} areaLeads={props.areaLeads} members={props.members} />}
           {section === 'invites' && <InvitesPanel isAdmin={props.isAdmin} invites={props.invites} />}
-          {section === 'onboarding' && <OnboardingPanel isAdmin={props.isAdmin} steps={props.onboardingSteps} />}
+          {section === 'onboarding' && <OnboardingPanel isAdmin={props.isAdmin} steps={props.onboardingSteps} forms={props.forms} />}
         </div>
       </div>
     </div>
diff --git a/app/(app)/customize/page.tsx b/app/(app)/customize/page.tsx
index 6286611..d7fb234 100644
--- a/app/(app)/customize/page.tsx
+++ b/app/(app)/customize/page.tsx
@@ -27,6 +27,7 @@ export default async function CustomizePage() {
     { data: tiers },
     { data: invites },
     { data: onboardingSteps },
+    { data: forms },
     { data: areas },
     { data: rolePerms },
     { data: areaLeads },
@@ -37,6 +38,7 @@ export default async function CustomizePage() {
     supabase.from('space_tiers').select('id, slug, name, description, monthly_price_cents, billing_cadence, is_system, is_archived, sort_order').eq('space_id', member.space_id).order('sort_order'),
     supabase.from('space_invites').select('id, code, label, expires_at, max_uses, uses_count, is_enabled, created_at').eq('space_id', member.space_id).order('created_at', { ascending: false }),
     supabase.from('space_onboarding_steps').select('id, step_key, step_type, title, body, config, is_enabled, is_required, is_system, sort_order').eq('space_id', member.space_id).order('sort_order'),
+    supabase.from('forms').select('id, title, kind, status').eq('space_id', member.space_id).order('created_at', { ascending: false }),
     supabase.from('space_areas').select('id, code, name, icon, sort_order, is_archived').eq('space_id', member.space_id).order('sort_order').order('name'),
     supabase.from('space_role_permissions').select('subject, permission').eq('space_id', member.space_id),
     supabase.from('area_leads').select('id, area_code, area_name, lead_id, lead_handle, status').eq('space_id', member.space_id).order('area_name'),
@@ -50,7 +52,8 @@ export default async function CustomizePage() {
       customRoles={(customRoles ?? []) as Array<{ id: string; slug: string; name: string; description: string | null; color: string | null; sort_order: number }>}
       tiers={(tiers ?? []) as Array<{ id: string; slug: string; name: string; description: string | null; monthly_price_cents: number; billing_cadence: string; is_system: boolean; is_archived: boolean; sort_order: number }>}
       invites={(invites ?? []) as Array<{ id: string; code: string; label: string | null; expires_at: string | null; max_uses: number | null; uses_count: number; is_enabled: boolean; created_at: string }>}
-      onboardingSteps={(onboardingSteps ?? []) as Array<{ id: string; step_key: string; step_type: 'welcome' | 'code_of_conduct' | 'profile' | 'payment' | 'content'; title: string; body: string | null; config: Record<string, unknown>; is_enabled: boolean; is_required: boolean; is_system: boolean; sort_order: number }>}
+      onboardingSteps={(onboardingSteps ?? []) as Array<{ id: string; step_key: string; step_type: 'welcome' | 'code_of_conduct' | 'profile' | 'payment' | 'content' | 'form'; title: string; body: string | null; config: Record<string, unknown>; is_enabled: boolean; is_required: boolean; is_system: boolean; sort_order: number }>}
+      forms={(forms ?? []) as Array<{ id: string; title: string; kind: string; status: string }>}
       areas={(areas ?? []) as Array<{ id: string; code: string; name: string; icon: string | null; sort_order: number; is_archived: boolean }>}
       rolePerms={(rolePerms ?? []) as Array<{ subject: string; permission: string }>}
       areaLeads={(areaLeads ?? []) as Array<{ id: string; area_code: string | null; area_name: string; lead_id: string | null; lead_handle: string | null; status: string }>}
diff --git a/app/(app)/customize/panels/onboarding-panel.tsx b/app/(app)/customize/panels/onboarding-panel.tsx
index d498243..27c99f7 100644
--- a/app/(app)/customize/panels/onboarding-panel.tsx
+++ b/app/(app)/customize/panels/onboarding-panel.tsx
@@ -7,29 +7,52 @@ import { createOnboardingStep, updateOnboardingStep, deleteOnboardingStep } from
 import { Card } from './card'
 import { useConfirm } from '@/components/ui/confirm'
 import { Empty, EmptyHeader, EmptyMedia, EmptyTitle, EmptyDescription } from '@/components/ui/empty'
-import type { Step } from './types'
+import type { Step, FormOption } from './types'
 
-export function OnboardingPanel({ isAdmin, steps: initial }: { isAdmin: boolean; steps: Step[] }) {
+export function OnboardingPanel({
+  isAdmin,
+  steps: initial,
+  forms,
+}: {
+  isAdmin: boolean
+  steps: Step[]
+  forms: FormOption[]
+}) {
   const confirm = useConfirm()
   const [steps, setSteps] = useState<Step[]>(initial)
+  const publishedForms = forms.filter(f => f.status === 'published')
 
   return (
     <Card
       title="New member onboarding"
       blurb="These steps run, in order, the first time a new member opens the app. Reorder with the number. Disable to hide. Built-in steps cannot be deleted, only disabled. Body supports markdown and a safe subset of HTML."
       action={isAdmin ? (
-        <button
-          onClick={async () => {
-            const result = await createOnboardingStep({ step_type: 'content', title: 'New step', body: 'Edit this content in Customize, Onboarding.', sort_order: steps.reduce((m, s) => Math.max(m, s.sort_order), 0) + 1 })
-            if ('error' in result && result.error) { toast.error(result.error); return }
-            toast.success('Step added')
-            const id = (result as { id: string }).id
-            setSteps(prev => [...prev, { id, step_key: `custom-${id.slice(0, 12)}`, step_type: 'content', title: 'New step', body: 'Edit this content in Customize, Onboarding.', config: {}, is_enabled: true, is_required: false, is_system: false, sort_order: prev.reduce((m, s) => Math.max(m, s.sort_order), 0) + 1 }])
-          }}
-          className="font-mono text-[10px] border border-border px-3 py-1.5 rounded hover:border-primary hover:text-primary transition whitespace-nowrap"
-        >
-          + Custom step
-        </button>
+        <div className="flex gap-2">
+          <button
+            onClick={async () => {
+              const result = await createOnboardingStep({ step_type: 'content', title: 'New step', body: 'Edit this content in Customize, Onboarding.', sort_order: steps.reduce((m, s) => Math.max(m, s.sort_order), 0) + 1 })
+              if ('error' in result && result.error) { toast.error(result.error); return }
+              toast.success('Step added')
+              const id = (result as { id: string }).id
+              setSteps(prev => [...prev, { id, step_key: `custom-${id.slice(0, 12)}`, step_type: 'content', title: 'New step', body: 'Edit this content in Customize, Onboarding.', config: {}, is_enabled: true, is_required: false, is_system: false, sort_order: prev.reduce((m, s) => Math.max(m, s.sort_order), 0) + 1 }])
+            }}
+            className="font-mono text-[10px] border border-border px-3 py-1.5 rounded hover:border-primary hover:text-primary transition whitespace-nowrap"
+          >
+            + Custom step
+          </button>
+          <button
+            onClick={async () => {
+              const result = await createOnboardingStep({ step_type: 'form', title: 'Sign a form or waiver', body: 'Pick which form members fill here.', sort_order: steps.reduce((m, s) => Math.max(m, s.sort_order), 0) + 1 })
+              if ('error' in result && result.error) { toast.error(result.error); return }
+              toast.success('Form step added — pick a form below')
+              const id = (result as { id: string }).id
+              setSteps(prev => [...prev, { id, step_key: `custom-${id.slice(0, 12)}`, step_type: 'form', title: 'Sign a form or waiver', body: 'Pick which form members fill here.', config: {}, is_enabled: true, is_required: false, is_system: false, sort_order: prev.reduce((m, s) => Math.max(m, s.sort_order), 0) + 1 }])
+            }}
+            className="font-mono text-[10px] border border-border px-3 py-1.5 rounded hover:border-primary hover:text-primary transition whitespace-nowrap"
+          >
+            + Form step
+          </button>
+        </div>
       ) : undefined}
     >
       {steps.length === 0 && (
@@ -50,9 +73,36 @@ export function OnboardingPanel({ isAdmin, steps: initial }: { isAdmin: boolean;
               <input type="text" defaultValue={s.title} disabled={!isAdmin} onBlur={async e => { const v = e.target.value.trim(); if (!v || v === s.title) return; const res = await updateOnboardingStep(s.id, { title: v }); if (res.error) { toast.error(res.error); return } setSteps(prev => prev.map(x => x.id === s.id ? { ...x, title: v } : x)) }} className="flex-1 min-w-[160px] bg-background border border-border text-foreground font-sans text-sm rounded px-2 py-1 focus:outline-none focus:border-primary" />
               {s.is_system && <span className="font-mono text-[10px] text-amber-600">built-in</span>}
             </div>
-            {(s.step_type === 'welcome' || s.step_type === 'code_of_conduct' || s.step_type === 'payment' || s.step_type === 'content') && (
+            {(s.step_type === 'welcome' || s.step_type === 'code_of_conduct' || s.step_type === 'payment' || s.step_type === 'content' || s.step_type === 'form') && (
               <textarea defaultValue={s.body ?? ''} disabled={!isAdmin} rows={4} maxLength={50000} onBlur={async e => { const v = e.target.value; if (v === (s.body ?? '')) return; const res = await updateOnboardingStep(s.id, { body: v }); if (res.error) { toast.error(res.error); return } setSteps(prev => prev.map(x => x.id === s.id ? { ...x, body: v } : x)) }} placeholder="Markdown / safe HTML" className="w-full bg-background border border-border text-foreground font-mono text-xs rounded px-2 py-2 focus:outline-none focus:border-primary mb-3" />
             )}
+            {s.step_type === 'form' && (
+              <div className="mb-3">
+                {publishedForms.length === 0 ? (
+                  <p className="font-sans text-xs text-muted-foreground">No published forms yet. Create and publish one under Forms &amp; waivers, then pick it here.</p>
+                ) : (
+                  <select
+                    defaultValue={(s.config?.form_id as string) ?? ''}
+                    disabled={!isAdmin}
+                    onChange={async e => {
+                      const v = e.target.value
+                      const res = await updateOnboardingStep(s.id, { config: { ...s.config, form_id: v } })
+                      if (res.error) { toast.error(res.error); return }
+                      setSteps(prev => prev.map(x => x.id === s.id ? { ...x, config: { ...x.config, form_id: v } } : x))
+                      toast.success('Form linked')
+                    }}
+                    className="w-full bg-background border border-border text-foreground font-sans text-sm rounded px-2 py-2 focus:outline-none focus:border-primary"
+                  >
+                    <option value="">Select a form…</option>
+                    {publishedForms.map(f => (
+                      <option key={f.id} value={f.id}>
+                        {f.title}{f.kind === 'waiver' ? ' (waiver)' : ''}
+                      </option>
+                    ))}
+                  </select>
+                )}
+              </div>
+            )}
             {s.step_type === 'payment' && (
               <input type="url" defaultValue={(s.config?.payment_url as string) ?? ''} disabled={!isAdmin} placeholder="Payment link (https://...)" onBlur={async e => { const v = e.target.value.trim(); if (v === ((s.config?.payment_url as string) ?? '')) return; const res = await updateOnboardingStep(s.id, { config: { ...s.config, payment_url: v } }); if (res.error) { toast.error(res.error); return } setSteps(prev => prev.map(x => x.id === s.id ? { ...x, config: { ...x.config, payment_url: v } } : x)) }} className="w-full bg-background border border-border text-foreground font-mono text-xs rounded px-2 py-2 focus:outline-none focus:border-primary mb-3" />
             )}
diff --git a/app/(app)/customize/panels/types.ts b/app/(app)/customize/panels/types.ts
index 762d038..7d64e5a 100644
--- a/app/(app)/customize/panels/types.ts
+++ b/app/(app)/customize/panels/types.ts
@@ -40,7 +40,14 @@ export interface Invite {
   created_at: string
 }
 
-export type OnboardingStepType = 'welcome' | 'code_of_conduct' | 'profile' | 'payment' | 'content'
+export type OnboardingStepType = 'welcome' | 'code_of_conduct' | 'profile' | 'payment' | 'content' | 'form'
+
+export interface FormOption {
+  id: string
+  title: string
+  kind: string
+  status: string
+}
 
 export interface Step {
   id: string
diff --git a/app/onboarding/onboarding-flow.tsx b/app/onboarding/onboarding-flow.tsx
index bb5e581..7aca9a1 100644
--- a/app/onboarding/onboarding-flow.tsx
+++ b/app/onboarding/onboarding-flow.tsx
@@ -5,14 +5,25 @@ import { useRouter } from 'next/navigation'
 import { toast } from 'sonner'
 import { BrandMark } from '@/components/brand-mark'
 import { SafeMarkdown } from '@/components/safe-markdown'
+import { FormRenderer } from '@/components/forms/form-renderer'
+import type { FormField } from '@/lib/forms-schema'
 import {
   markOnboardingStepDone,
   finishOnboarding,
   skipOnboarding,
   updateMyProfile,
+  submitForm,
 } from '@/lib/actions'
 
-type StepType = 'welcome' | 'code_of_conduct' | 'profile' | 'payment' | 'content'
+type StepType = 'welcome' | 'code_of_conduct' | 'profile' | 'payment' | 'content' | 'form'
+
+interface StepFormDef {
+  id: string
+  title: string
+  kind: string
+  legalText: string | null
+  fields: FormField[]
+}
 
 interface Step {
   id: string
@@ -21,6 +32,8 @@ interface Step {
   body: string | null
   config: Record<string, unknown>
   is_required: boolean
+  formDef?: StepFormDef | null
+  alreadySubmitted?: boolean
 }
 
 interface Props {
@@ -45,6 +58,8 @@ export function OnboardingFlow({ spaceName, steps, canSkip, profile: initialProf
   // Controlled raw text for the skills field so edits survive navigating
   // Back/forward and the user sees exactly what they typed (no normalize).
   const [skillsText, setSkillsText] = useState(initialProfile.skills.join(', '))
+  const [formAnswers, setFormAnswers] = useState<Record<string, Record<string, unknown>>>({})
+  const [formConsent, setFormConsent] = useState<Record<string, boolean>>({})
 
   const step = steps[index]
   const isLast = index === steps.length - 1
@@ -52,6 +67,12 @@ export function OnboardingFlow({ spaceName, steps, canSkip, profile: initialProf
   const ackLabel = (step.config?.ack_label as string) || 'I have read and agree'
   const ackOk = !requireAck || acked[step.id]
 
+  const isFormStep = step.step_type === 'form'
+  const formDef = step.formDef ?? null
+  const formActionable = isFormStep && formDef && !step.alreadySubmitted
+  const isWaiver = formDef?.kind === 'waiver'
+  const consentOk = !formActionable || !isWaiver || formConsent[step.id] === true
+
   async function advance() {
     setBusy(true)
     await markOnboardingStepDone(step.id)
@@ -95,6 +116,28 @@ export function OnboardingFlow({ spaceName, steps, canSkip, profile: initialProf
     else setIndex(i => i + 1)
   }
 
+  async function submitFormStep() {
+    setBusy(true)
+    // No form to fill (already done, or misconfigured/unpublished): treat as a
+    // plain non-blocking step so a member is never trapped.
+    if (formActionable && formDef) {
+      const res = await submitForm({
+        formId: formDef.id,
+        answers: formAnswers[step.id] ?? {},
+        consent: isWaiver ? formConsent[step.id] === true : undefined,
+      })
+      if ('error' in res && res.error) {
+        setBusy(false)
+        toast.error(res.error)
+        return
+      }
+    }
+    await markOnboardingStepDone(step.id)
+    setBusy(false)
+    if (isLast) await finish()
+    else setIndex(i => i + 1)
+  }
+
   const progressPct = Math.round(((index) / steps.length) * 100)
 
   return (
@@ -193,6 +236,48 @@ export function OnboardingFlow({ spaceName, steps, canSkip, profile: initialProf
                   </a>
                 )}
               </div>
+            ) : step.step_type === 'form' ? (
+              <div className="space-y-4">
+                {step.body && <SafeMarkdown>{step.body}</SafeMarkdown>}
+                {!formDef ? (
+                  <p className="font-sans text-sm text-muted-foreground">
+                    This form is not available right now. You can continue.
+                  </p>
+                ) : step.alreadySubmitted ? (
+                  <p className="font-sans text-sm text-muted-foreground">
+                    You have already completed this. You can continue.
+                  </p>
+                ) : (
+                  <>
+                    {isWaiver && formDef.legalText && (
+                      <div className="max-h-72 overflow-y-auto whitespace-pre-wrap rounded border border-border bg-muted/30 p-3 font-sans text-sm">
+                        {formDef.legalText}
+                      </div>
+                    )}
+                    <FormRenderer
+                      fields={formDef.fields}
+                      values={formAnswers[step.id] ?? {}}
+                      onChange={(k, v) =>
+                        setFormAnswers(p => ({ ...p, [step.id]: { ...(p[step.id] ?? {}), [k]: v } }))
+                      }
+                      idPrefix={`ob-${step.id}`}
+                    />
+                    {isWaiver && (
+                      <label className="flex items-start gap-2 cursor-pointer">
+                        <input
+                          type="checkbox"
+                          checked={formConsent[step.id] === true}
+                          onChange={e => setFormConsent(p => ({ ...p, [step.id]: e.target.checked }))}
+                          className="mt-0.5"
+                        />
+                        <span className="font-sans text-sm text-foreground">
+                          I have read and agree to the terms above.
+                        </span>
+                      </label>
+                    )}
+                  </>
+                )}
+              </div>
             ) : (
               <div className="space-y-4">
                 {step.body && <SafeMarkdown>{step.body}</SafeMarkdown>}
@@ -233,11 +318,27 @@ export function OnboardingFlow({ spaceName, steps, canSkip, profile: initialProf
                 </button>
               )}
               <button
-                onClick={step.step_type === 'profile' ? saveProfileAndAdvance : advance}
-                disabled={busy || !ackOk}
+                onClick={
+                  step.step_type === 'profile'
+                    ? saveProfileAndAdvance
+                    : step.step_type === 'form'
+                      ? submitFormStep
+                      : advance
+                }
+                disabled={busy || !ackOk || !consentOk}
                 className="bg-primary text-white text-sm font-sans px-4 py-2 rounded hover:bg-primary/90 transition disabled:opacity-50"
               >
-                {busy ? 'Saving...' : isLast ? 'Finish' : step.step_type === 'payment' ? 'I have set this up' : 'Continue'}
+                {busy
+                  ? 'Saving...'
+                  : isLast
+                    ? 'Finish'
+                    : step.step_type === 'payment'
+                      ? 'I have set this up'
+                      : formActionable
+                        ? isWaiver
+                          ? 'Sign & continue'
+                          : 'Submit & continue'
+                        : 'Continue'}
               </button>
             </div>
           </div>
diff --git a/app/onboarding/page.tsx b/app/onboarding/page.tsx
index eba8d44..d1ef46e 100644
--- a/app/onboarding/page.tsx
+++ b/app/onboarding/page.tsx
@@ -1,5 +1,7 @@
 import { redirect } from 'next/navigation'
 import { createClient } from '@/lib/supabase/server'
+import { createAdminClient } from '@/lib/supabase/admin'
+import { parseFormSchema } from '@/lib/forms-schema'
 import { OnboardingFlow } from './onboarding-flow'
 
 export const dynamic = 'force-dynamic'
@@ -40,17 +42,77 @@ export default async function OnboardingPage() {
   const canSkip = !steps.some(s => s.is_required)
   const spaceName = (member.spaces as { name?: string } | null)?.name ?? 'your space'
 
+  // Enrich form steps with the referenced (published) form and whether this
+  // member has already submitted it. Unpublished/missing forms resolve to no
+  // formDef; the flow then shows a non-blocking notice (mirrors the
+  // fail-open in finishOnboarding).
+  const formIds = Array.from(
+    new Set(
+      steps
+        .filter(s => s.step_type === 'form')
+        .map(s => (s.config as { form_id?: string } | null)?.form_id)
+        .filter((x): x is string => typeof x === 'string'),
+    ),
+  )
+
+  const formDefs = new Map<
+    string,
+    { id: string; title: string; kind: string; legal_text: string | null; fields: ReturnType<typeof parseFormSchema> }
+  >()
+  const submittedFormIds = new Set<string>()
+
+  if (formIds.length > 0) {
+    const { data: formRows } = await supabase
+      .from('forms')
+      .select('id, title, kind, legal_text, schema, status')
+      .eq('space_id', member.space_id)
+      .in('id', formIds)
+      .eq('status', 'published')
+    for (const f of formRows ?? []) {
+      formDefs.set(f.id, {
+        id: f.id,
+        title: f.title,
+        kind: f.kind,
+        legal_text: f.legal_text,
+        fields: parseFormSchema(f.schema),
+      })
+    }
+    // Submissions are forms.manage-only under RLS; probe with the service client.
+    const admin = createAdminClient()
+    const { data: subs } = await admin
+      .from('form_submissions')
+      .select('form_id')
+      .eq('space_id', member.space_id)
+      .eq('member_id', member.id)
+      .in('form_id', formIds)
+    for (const r of subs ?? []) submittedFormIds.add(r.form_id as string)
+  }
+
   return (
     <OnboardingFlow
       spaceName={spaceName}
-      steps={steps.map(s => ({
-        id: s.id,
-        step_type: s.step_type as 'welcome' | 'code_of_conduct' | 'profile' | 'payment' | 'content',
-        title: s.title,
-        body: s.body,
-        config: (s.config ?? {}) as Record<string, unknown>,
-        is_required: s.is_required,
-      }))}
+      steps={steps.map(s => {
+        const formId = (s.config as { form_id?: string } | null)?.form_id
+        const def = formId ? formDefs.get(formId) : undefined
+        return {
+          id: s.id,
+          step_type: s.step_type as 'welcome' | 'code_of_conduct' | 'profile' | 'payment' | 'content' | 'form',
+          title: s.title,
+          body: s.body,
+          config: (s.config ?? {}) as Record<string, unknown>,
+          is_required: s.is_required,
+          formDef: def
+            ? {
+                id: def.id,
+                title: def.title,
+                kind: def.kind,
+                legalText: def.legal_text,
+                fields: def.fields,
+              }
+            : null,
+          alreadySubmitted: formId ? submittedFormIds.has(formId) : false,
+        }
+      })}
       canSkip={canSkip}
       profile={{
         display_name: member.display_name ?? '',
diff --git a/docs/API_REFERENCE.md b/docs/API_REFERENCE.md
index 4292755..994c159 100644
--- a/docs/API_REFERENCE.md
+++ b/docs/API_REFERENCE.md
@@ -894,4 +894,6 @@ Management actions are gated by `forms.manage` (checked via the `user_has_permis
 - `submitForm(input)` — public entry point (anonymous, signed-in non-member, or member by form `visibility`). Reads the form with the service client (anon has no `forms` grant), enforces visibility + waiver consent, validates `answers` against the stored field schema (`lib/forms-schema.ts`, unknown keys discarded), snapshots schema/legal-text/version, captures IP + user-agent, and writes the row with the service client (`form_submissions` has no write policy, so this is the only path; rows are immutable).
 - `linkSubmissionsForMember(input)` — `forms.manage` admin manual-link of prior anonymous submissions by email. The automatic verified-email retro-link is Phase 5.
 
-Not implemented yet (planned): builder UI, public `/f/[slug]` page, onboarding form-step integration, automatic retro-link on email verification.
+Onboarding integration (Phase 4, migration 027): a `space_onboarding_steps` step can have `step_type = 'form'` with `config.form_id`. The onboarding flow renders the form/waiver and submits via `submitForm`; `finishOnboarding` treats a required form step as satisfied if a submission for that form by the member already exists (any version — re-sign is non-blocking), and fails open if the configured form is missing/unpublished so a misconfiguration cannot trap members.
+
+Not implemented yet (planned): automatic retro-link on email verification + join/signup/addMember/import hooks (Phase 5). The `linkSubmissionsForMember` primitive exists.
diff --git a/docs/ARCHITECTURE.md b/docs/ARCHITECTURE.md
index 370fcf6..0100b58 100644
--- a/docs/ARCHITECTURE.md
+++ b/docs/ARCHITECTURE.md
@@ -422,10 +422,11 @@ forms + waivers).
 
 ### Forms & waivers (migration 026 — Phase 1: schema + RLS)
 
-`forms` and `form_submissions` back a custom form/waiver builder. Phases 1-3
+`forms` and `form_submissions` back a custom form/waiver builder. Phases 1-4
 are done (schema + RLS; server actions in `lib/actions/forms.ts`; the builder
-UI under `/forms` + the public `/f/[slug]` page). Onboarding integration and
-automatic retro-linking are Phases 4-5. Security shape:
+UI under `/forms` + the public `/f/[slug]` page; onboarding `form` step type
+with required-waiver enforcement + auto-satisfy, migration 027). Automatic
+retro-linking on email verification is Phase 5. Security shape:
 all submissions (anonymous, public-authenticated, or members) are written by a
 single validated server action using the service client AFTER server-side
 schema validation and snapshotting (same pattern as `finishOnboarding`); the
diff --git a/docs/DATABASE_SCHEMA.md b/docs/DATABASE_SCHEMA.md
index ea93fba..17e0e9a 100644
--- a/docs/DATABASE_SCHEMA.md
+++ b/docs/DATABASE_SCHEMA.md
@@ -686,7 +686,7 @@ CREATE INDEX idx_activity_space ON activity_log(space_id, created_at);
 
 ---
 
-## Migrations 014-026 (additions since the 13-table baseline)
+## Migrations 014-027 (additions since the 13-table baseline)
 
 `scripts/schema.sql` is the canonical idempotent schema; each numbered
 migration is mirrored as a section in it. Tables/columns added:
@@ -705,6 +705,7 @@ migration is mirrored as a section in it. Tables/columns added:
 | 023 | `space_role_permissions`, `ops_acl`; `user_effective_roles()`, `user_has_permission()` (SECURITY DEFINER); `secrets`/`knowledge_base` SELECT rewritten as `existing-rule OR ops_acl-match` (additive) |
 | 024 | `prevent_member_self_role_change()` extended to also block self-change of `tier_id` and `onboarding_completed_at` |
 | 025 | Re-asserts the hardened `incidents_insert` policy verbatim (production convergence; access-neutral, no schema change) |
+| 027 | Adds `'form'` to the `space_onboarding_steps.step_type` CHECK so an onboarding step can embed a custom form/waiver (referenced form id stored in the step's existing `config` jsonb; no new column) |
 | 026 | `forms`, `form_submissions` (custom forms + waivers). Globally-unique form slug; jsonb field schema; per-submission snapshot of schema/legal-text/version for immutable waiver records. RLS additive + default-deny: forms SELECT = `forms.manage` holders (all) or members (published only), write = `user_has_permission(..., 'forms.manage')`; form_submissions SELECT = `forms.manage` only, NO write policy (every submission is written by one validated service-client server action, and submissions are immutable). New `forms.manage` permission seeded to board + backfilled |
 
 New enum: `comment_entity_type` = `forum_thread | proposal | incident | policy`.
diff --git a/docs/HANDOFF.md b/docs/HANDOFF.md
index b72c7a3..e7f96d9 100644
--- a/docs/HANDOFF.md
+++ b/docs/HANDOFF.md
@@ -4,7 +4,7 @@ Append-only. Newest entries on top. Keep each entry to one screen.
 
 ---
 
-## 2026-05-16 (pass 18) — Forms + waivers Phases 1-3 (schema/RLS + server actions + builder UI), LOCAL, awaiting deploy approval
+## 2026-05-16 (pass 18) — Forms + waivers Phases 1-4 (schema/RLS + actions + builder UI + onboarding step), LOCAL, awaiting deploy approval
 
 Branch: `main`. Migration: `026` (not yet deployed). `pnpm build` + `pnpm exec vitest run` gate pending in this entry's session.
 
@@ -47,11 +47,21 @@ Audited the migration before continuing. Three fixes applied: dropped redundant
 - Gate: `pnpm exec vitest run` 285/285; `pnpm build` exit 0; `/forms`, `/forms/[id]`, `/forms/new`, `/f/[slug]` all compiled.
 - NOT browser-verified (no live browser this session): smoke-test the builder (add/reorder/remove fields, live preview, create + edit + publish + close + delete), the results CSV download, and a public submission for each visibility (anon, public_auth signed-out gate, waiver consent).
 
+### Forms + waivers Phase 4 (this session) — onboarding form step, LOCAL
+
+- `scripts/027_onboarding_form_step.sql` (idempotent constraint replace) + `schema.sql` Section 14 inline CHECK now allows `step_type = 'form'`. Referenced form id lives in the step's existing `config.form_id` (no new column). validations `onboardingStepTypeSchema` + onboarding action union + customize types/casts include `'form'`.
+- `finishOnboarding`: a required `form` step is satisfied if a submission for `config.form_id` by this member exists (any version — non-blocking re-sign / auto-satisfy). Fails open if the form is missing or unpublished so a misconfig cannot trap a member out of their space. Submission probe uses the service client (submissions are forms.manage-only under RLS).
+- `app/onboarding/page.tsx` enriches `form` steps with the published form def + a prior-submission flag; `onboarding-flow.tsx` renders `FormRenderer` + waiver legal text/consent and submits via `submitForm` then `markOnboardingStepDone`; already-submitted or unavailable forms show a non-blocking notice.
+- Admin: `customize/page.tsx` fetches the space's forms; `onboarding-panel.tsx` gets a "+ Form step" button and a form `<select>` (writes `config.form_id`); empty-state hint when no published forms.
+- Tests: `__tests__/forms.test.ts` +2 (onboarding form-step contract). Gate: `pnpm exec vitest run` 287/287; `pnpm build` exit 0; onboarding + customize compiled. NOT unit-tested: `finishOnboarding` enforcement/auto-satisfy is DB-bound (no mocked test); covered by reasoning + manual.
+- NOT browser-verified: admin adds a form step + picks a form; member onboarding renders/sumbits the form/waiver; required-form blocks finish until submitted; auto-satisfy when a prior submission exists; fail-open on unpublished form.
+
 ### Open / next
 
-- **Awaiting user approval to deploy** (push to `main` = prod). Phases 1-3 are all LOCAL (commits `3a2d3ca`, `66dd9b7`, Phase 2, Phase 3); do NOT push without explicit go. Migration `026` ships with the first push.
-- Phases 4-5 not started: onboarding form-step + required-waiver enforcement + auto-satisfy when a matching signed waiver exists; automatic retro-link hooks (join/signup/addMember/import + email verification) — `linkSubmissionsForMember` primitive already exists. Phase 3 is code-complete but NOT browser-verified (see Phase 3 smoke-test list above).
-- After an approved push: watch the Actions run, then smoke-test that `026` applied (`_migrations_applied` row) and a space's board has `forms.manage`.
+- **Awaiting user approval to deploy** (push to `main` = prod). Phases 1-4 are all LOCAL; do NOT push without explicit go. Migrations `026` + `027` ship with the first push.
+- Phase 5 not started: automatic retro-link on email verification + join/signup/addMember/import hooks — `linkSubmissionsForMember` primitive already exists (currently exposed as the forms.manage manual-link).
+- Phases 3-4 are code-complete but NOT browser-verified (see the smoke-test lists in each subsection). No live browser this session.
+- After an approved push: watch the Actions run; smoke-test that `026`+`027` applied (`_migrations_applied`), a space's board has `forms.manage`, and the builder/public page/onboarding form step work end to end.
 
 ---
 
diff --git a/lib/actions/onboarding.ts b/lib/actions/onboarding.ts
index 79ce6a4..c61a935 100644
--- a/lib/actions/onboarding.ts
+++ b/lib/actions/onboarding.ts
@@ -15,7 +15,7 @@ const ONBOARDING_ADMIN_ROLES = ['admin', 'board'] as const
 // --- Admin: manage steps -----------------------------------------------------
 
 export async function createOnboardingStep(input: {
-  step_type: 'welcome' | 'code_of_conduct' | 'profile' | 'payment' | 'content'
+  step_type: 'welcome' | 'code_of_conduct' | 'profile' | 'payment' | 'content' | 'form'
   title: string
   body?: string | null
   config?: Record<string, unknown>
@@ -157,7 +157,7 @@ export async function finishOnboarding() {
 
   const { data: steps } = await supabase
     .from('space_onboarding_steps')
-    .select('id, is_required, is_enabled')
+    .select('id, is_required, is_enabled, step_type, config')
     .eq('space_id', member.space_id)
     .eq('is_enabled', true)
 
@@ -169,9 +169,39 @@ export async function finishOnboarding() {
 
   const progress = (row?.onboarding_progress ?? {}) as { completed_step_ids?: string[] }
   const done = new Set(progress.completed_step_ids ?? [])
-  const requiredMissing = (steps ?? []).filter(s => s.is_required && !done.has(s.id))
-  if (requiredMissing.length > 0) {
-    return { error: 'Please complete the required steps before finishing.' }
+  const candidates = (steps ?? []).filter(s => s.is_required && !done.has(s.id))
+
+  // A required 'form' step is also satisfied if a submission for the
+  // configured form already exists for this member (any version — re-sign is
+  // non-blocking). If the form is missing or not published, the step is
+  // treated as non-blocking: a misconfiguration must not trap members out of
+  // their own space. Submissions are forms.manage-only under RLS, so the
+  // existence probe uses the service client.
+  const admin = createAdminClient()
+  for (const s of candidates) {
+    if (s.step_type !== 'form') {
+      return { error: 'Please complete the required steps before finishing.' }
+    }
+    const formId = (s.config as { form_id?: string } | null)?.form_id
+    if (!formId) continue
+
+    const { data: form } = await supabase
+      .from('forms')
+      .select('id, status')
+      .eq('id', formId)
+      .eq('space_id', member.space_id)
+      .maybeSingle()
+    if (!form || form.status !== 'published') continue
+
+    const { count } = await admin
+      .from('form_submissions')
+      .select('id', { count: 'exact', head: true })
+      .eq('form_id', formId)
+      .eq('space_id', member.space_id)
+      .eq('member_id', member.id)
+    if ((count ?? 0) === 0) {
+      return { error: 'Please complete the required form before finishing.' }
+    }
   }
 
   // onboarding_completed_at is blocked by the self-change trigger (migration
diff --git a/lib/validations.ts b/lib/validations.ts
index dfe5f36..fde1f29 100644
--- a/lib/validations.ts
+++ b/lib/validations.ts
@@ -331,7 +331,7 @@ export const updateMyProfileSchema = z.object({
 
 // ─── Onboarding ──────────────────────────────────────────────────────────────
 
-export const onboardingStepTypeSchema = z.enum(['welcome', 'code_of_conduct', 'profile', 'payment', 'content'])
+export const onboardingStepTypeSchema = z.enum(['welcome', 'code_of_conduct', 'profile', 'payment', 'content', 'form'])
 
 export const createOnboardingStepSchema = z.object({
   step_type: onboardingStepTypeSchema,
diff --git a/scripts/027_onboarding_form_step.sql b/scripts/027_onboarding_form_step.sql
new file mode 100644
index 0000000..7740c5b
--- /dev/null
+++ b/scripts/027_onboarding_form_step.sql
@@ -0,0 +1,20 @@
+-- =============================================================================
+-- 027: Allow an onboarding step to embed a custom form / waiver
+-- =============================================================================
+-- Adds 'form' to the space_onboarding_steps.step_type CHECK so a space can
+-- require a custom form or waiver as an onboarding step. The referenced form
+-- is stored in the step's existing `config` jsonb as { "form_id": "<uuid>" };
+-- no new column is needed.
+--
+-- step_type is a TEXT column with a column-level CHECK, not a Postgres enum,
+-- so this is a constraint replacement (the only safe path for a CHECK), done
+-- by the auto-generated constraint name. Idempotent: DROP CONSTRAINT IF EXISTS
+-- then ADD.
+-- =============================================================================
+
+ALTER TABLE public.space_onboarding_steps
+  DROP CONSTRAINT IF EXISTS space_onboarding_steps_step_type_check;
+
+ALTER TABLE public.space_onboarding_steps
+  ADD CONSTRAINT space_onboarding_steps_step_type_check
+  CHECK (step_type IN ('welcome','code_of_conduct','profile','payment','content','form'));
diff --git a/scripts/schema.sql b/scripts/schema.sql
index b074e1e..2d3c417 100644
--- a/scripts/schema.sql
+++ b/scripts/schema.sql
@@ -1628,7 +1628,7 @@ CREATE TABLE IF NOT EXISTS public.space_onboarding_steps (
   id          uuid        PRIMARY KEY DEFAULT uuid_generate_v4(),
   space_id    uuid        NOT NULL REFERENCES public.spaces(id) ON DELETE CASCADE,
   step_key    text        NOT NULL CHECK (char_length(step_key) BETWEEN 1 AND 60),
-  step_type   text        NOT NULL CHECK (step_type IN ('welcome','code_of_conduct','profile','payment','content')),
+  step_type   text        NOT NULL CHECK (step_type IN ('welcome','code_of_conduct','profile','payment','content','form')),
   title       text        NOT NULL CHECK (char_length(title) BETWEEN 1 AND 200),
   body        text,
   config      jsonb       NOT NULL DEFAULT '{}',