diff --git a/app/api/util.ts b/app/api/util.ts
index 79a06b87d..fb763d494 100644
--- a/app/api/util.ts
+++ b/app/api/util.ts
@@ -131,6 +131,10 @@ const instanceActions = {
   updateNic: ['stopped'],
   // https://github.com/oxidecomputer/omicron/blob/6dd9802/nexus/src/app/instance.rs#L1520-L1522
   serialConsole: ['running', 'rebooting', 'migrating', 'repairing'],
+
+  // https://github.com/oxidecomputer/omicron/blob/5e27bde/nexus/src/app/affinity.rs#L357 checks to see that there's no VMM
+  // TODO: determine whether the intent is only `stopped` or also `failed`
+  addToAntiAffinityGroup: ['stopped'],
 } satisfies Record<string, InstanceState[]>
 
 // setting .states is a cute way to make it ergonomic to call the test function
diff --git a/app/forms/anti-affinity-group-member-add.tsx b/app/forms/anti-affinity-group-member-add.tsx
index 64a6c8b5c..d6fe97e35 100644
--- a/app/forms/anti-affinity-group-member-add.tsx
+++ b/app/forms/anti-affinity-group-member-add.tsx
@@ -33,7 +33,7 @@ export default function AddAntiAffinityGroupMemberForm({ instances, onDismiss }:
     onSuccess(_data, variables) {
       onDismiss()
       queryClient.invalidateEndpoint('antiAffinityGroupMemberList')
-      queryClient.invalidateEndpoint('antiAffinityGroupView')
+      queryClient.invalidateEndpoint('instanceAntiAffinityGroupList')
       addToast(<>Instance <HL>{variables.path.instance}</HL> added to anti-affinity group <HL>{antiAffinityGroup}</HL></>) // prettier-ignore
     },
   })
diff --git a/app/pages/project/affinity/AntiAffinityGroupPage.tsx b/app/pages/project/affinity/AntiAffinityGroupPage.tsx
index 92c3a908a..8fca74f4d 100644
--- a/app/pages/project/affinity/AntiAffinityGroupPage.tsx
+++ b/app/pages/project/affinity/AntiAffinityGroupPage.tsx
@@ -100,7 +100,7 @@ export default function AntiAffinityPage() {
     {
       onSuccess(_data, variables) {
         queryClient.invalidateEndpoint('antiAffinityGroupMemberList')
-        queryClient.invalidateEndpoint('antiAffinityGroupView')
+        queryClient.invalidateEndpoint('instanceAntiAffinityGroupList')
         addToast(<>Member <HL>{variables.path.instance}</HL> removed from anti-affinity group <HL>{group.name}</HL></>) // prettier-ignore
       },
     }
diff --git a/app/pages/project/instances/AntiAffinityCard.tsx b/app/pages/project/instances/AntiAffinityCard.tsx
index 6d4c237a7..fdaa4606c 100644
--- a/app/pages/project/instances/AntiAffinityCard.tsx
+++ b/app/pages/project/instances/AntiAffinityCard.tsx
@@ -7,10 +7,15 @@
  */
 
 import { createColumnHelper, getCoreRowModel, useReactTable } from '@tanstack/react-table'
-import { useMemo } from 'react'
+import { useCallback, useId, useMemo, useState } from 'react'
+import { useForm } from 'react-hook-form'
+import * as R from 'remeda'
 
 import {
   apiq,
+  instanceCan,
+  queryClient,
+  useApiMutation,
   usePrefetchedQuery,
   type AffinityGroup,
   type AntiAffinityGroup,
@@ -18,24 +23,43 @@ import {
 import { Affinity24Icon } from '@oxide/design-system/icons/react'
 
 import { AffinityPolicyHeader } from '~/components/AffinityDocsPopover'
+import { ComboboxField } from '~/components/form/fields/ComboboxField'
+import { HL } from '~/components/HL'
 import { useInstanceSelector } from '~/hooks/use-params'
 import { AffinityGroupPolicyBadge } from '~/pages/project/affinity/AffinityPage'
+import { confirmAction } from '~/stores/confirm-action'
+import { addToast } from '~/stores/toast'
 import { makeLinkCell } from '~/table/cells/LinkCell'
+import { useColsWithActions, type MenuAction } from '~/table/columns/action-col'
 import { Columns } from '~/table/columns/common'
 import { Table } from '~/table/Table'
+import { Button } from '~/ui/lib/Button'
 import { CardBlock } from '~/ui/lib/CardBlock'
+import { toComboboxItems } from '~/ui/lib/Combobox'
 import { EmptyMessage } from '~/ui/lib/EmptyMessage'
+import { Modal } from '~/ui/lib/Modal'
 import { TableEmptyBox } from '~/ui/lib/Table'
 import { ALL_ISH } from '~/util/consts'
 import { pb } from '~/util/path-builder'
 import type * as PP from '~/util/path-params'
 
-export const antiAffinityGroupList = ({ project, instance }: PP.Instance) =>
+export const instanceAntiAffinityGroups = ({ project, instance }: PP.Instance) =>
   apiq('instanceAntiAffinityGroupList', {
     path: { instance },
     query: { project, limit: ALL_ISH },
   })
 
+export const allAntiAffinityGroups = ({ project }: PP.Project) =>
+  apiq('antiAffinityGroupList', {
+    query: { project, limit: ALL_ISH },
+  })
+
+const instanceView = ({ project, instance }: PP.Instance) =>
+  apiq('instanceView', {
+    path: { instance },
+    query: { project },
+  })
+
 const colHelper = createColumnHelper<AffinityGroup | AntiAffinityGroup>()
 const staticCols = [
   colHelper.accessor('description', Columns.description),
@@ -47,14 +71,67 @@ const staticCols = [
 
 export function AntiAffinityCard() {
   const instanceSelector = useInstanceSelector()
-  const { project } = instanceSelector
+  const { project, instance } = instanceSelector
+
+  const { data: memberGroups } = usePrefetchedQuery(
+    instanceAntiAffinityGroups(instanceSelector)
+  )
+  const { data: allGroups } = usePrefetchedQuery(allAntiAffinityGroups(instanceSelector))
+  const { data: instanceData } = usePrefetchedQuery(instanceView(instanceSelector))
+
+  const nonMemberGroups = useMemo(
+    () => R.differenceWith(allGroups.items, memberGroups.items, (a, b) => a.id === b.id),
+    [memberGroups, allGroups]
+  )
 
-  const { data: antiAffinityGroups } = usePrefetchedQuery(
-    antiAffinityGroupList(instanceSelector)
+  const { mutateAsync: removeMember } = useApiMutation(
+    'antiAffinityGroupMemberInstanceDelete',
+    {
+      onSuccess(_data, variables) {
+        addToast(
+          <>
+            Instance <b>{variables.path.instance}</b> removed from anti-affinity group{' '}
+            <b>{variables.path.antiAffinityGroup}</b>
+          </>
+        )
+        queryClient.invalidateEndpoint('instanceAntiAffinityGroupList')
+        queryClient.invalidateEndpoint('antiAffinityGroupMemberList')
+      },
+    }
   )
 
-  const antiAffinityCols = useMemo(
-    () => [
+  const makeActions = useCallback(
+    (group: AffinityGroup | AntiAffinityGroup): MenuAction[] => [
+      {
+        label: 'Remove instance from group',
+        onActivate() {
+          confirmAction({
+            actionType: 'danger',
+            doAction: () =>
+              removeMember({
+                path: {
+                  antiAffinityGroup: group.name,
+                  instance,
+                },
+                query: { project },
+              }),
+            modalTitle: 'Remove instance from group',
+            modalContent: (
+              <p>
+                Are you sure you want to remove instance <b>{instance}</b> from group{' '}
+                <b>{group.name}</b>?
+              </p>
+            ),
+            errorTitle: 'Error removing instance from group',
+          })
+        },
+      },
+    ],
+    [instance, project, removeMember]
+  )
+
+  const antiAffinityCols = useColsWithActions(
+    [
       colHelper.accessor('name', {
         cell: makeLinkCell((antiAffinityGroup) =>
           pb.antiAffinityGroup({ project, antiAffinityGroup })
@@ -62,21 +139,42 @@ export function AntiAffinityCard() {
       }),
       ...staticCols,
     ],
-    [project]
+    makeActions,
+    'Copy group ID'
   )
 
-  // Create tables for both types of groups
+  const [isModalOpen, setIsModalOpen] = useState(false)
+
   const antiAffinityTable = useReactTable({
     columns: antiAffinityCols,
-    data: antiAffinityGroups.items,
+    data: memberGroups.items,
     getCoreRowModel: getCoreRowModel(),
   })
 
+  let disabledReason = undefined
+  if (!instanceCan.addToAntiAffinityGroup(instanceData)) {
+    disabledReason =
+      <>Only <HL>stopped</HL> instances can be added to a group</> // prettier-ignore
+  } else if (allGroups.items.length === 0) {
+    disabledReason = 'No groups found'
+  } else if (nonMemberGroups.length === 0) {
+    disabledReason = 'Instance is already in all groups'
+  }
+
   return (
     <CardBlock>
-      <CardBlock.Header title="Anti-affinity groups" titleId="anti-affinity-groups-label" />
+      <CardBlock.Header title="Anti-affinity groups" titleId="anti-affinity-groups-label">
+        <Button
+          size="sm"
+          disabled={!!disabledReason}
+          disabledReason={disabledReason}
+          onClick={() => setIsModalOpen(true)}
+        >
+          Add to group
+        </Button>
+      </CardBlock.Header>
       <CardBlock.Body>
-        {antiAffinityGroups.items.length > 0 ? (
+        {memberGroups.items.length > 0 ? (
           <Table
             aria-labelledby="anti-affinity-groups-label"
             table={antiAffinityTable}
@@ -92,6 +190,68 @@ export function AntiAffinityCard() {
           </TableEmptyBox>
         )}
       </CardBlock.Body>
+      {isModalOpen && (
+        <AddToGroupModal
+          onDismiss={() => setIsModalOpen(false)}
+          nonMemberGroups={nonMemberGroups}
+        />
+      )}
     </CardBlock>
   )
 }
+
+type ModalProps = {
+  onDismiss: () => void
+  nonMemberGroups: (AffinityGroup | AntiAffinityGroup)[]
+}
+
+export function AddToGroupModal({ onDismiss, nonMemberGroups }: ModalProps) {
+  const { project, instance } = useInstanceSelector()
+
+  const form = useForm({ defaultValues: { group: '' } })
+  const formId = useId()
+
+  const { mutateAsync: addMember } = useApiMutation('antiAffinityGroupMemberInstanceAdd', {
+    onSuccess(_data, variables) {
+      onDismiss()
+      queryClient.invalidateEndpoint('antiAffinityGroupMemberList')
+      queryClient.invalidateEndpoint('instanceAntiAffinityGroupList')
+      addToast(
+        <>
+          Instance <HL>{instance}</HL> added to anti-affinity group{' '}
+          <HL>{variables.path.antiAffinityGroup}</HL>
+        </>
+      )
+    },
+  })
+
+  const handleSubmit = form.handleSubmit(({ group }) => {
+    addMember({
+      path: { antiAffinityGroup: group, instance },
+      query: { project },
+    })
+  })
+
+  return (
+    <Modal isOpen onDismiss={onDismiss} title="Add to anti-affinity group">
+      <Modal.Body>
+        <Modal.Section>
+          <p className="mb-6">
+            Select a group to add instance <HL>{instance}</HL> to.
+          </p>
+          <form id={formId} onSubmit={handleSubmit}>
+            <ComboboxField
+              label="Anti-affinity group"
+              placeholder="Select a group"
+              name="group"
+              items={toComboboxItems(nonMemberGroups)}
+              required
+              control={form.control}
+            />
+          </form>
+        </Modal.Section>
+      </Modal.Body>
+      <Modal.Footer onDismiss={onDismiss} formId={formId} actionText="Add to group" />
+    </Modal>
+  )
+}
diff --git a/app/pages/project/instances/NetworkingTab.tsx b/app/pages/project/instances/NetworkingTab.tsx
index de2b8326e..845422662 100644
--- a/app/pages/project/instances/NetworkingTab.tsx
+++ b/app/pages/project/instances/NetworkingTab.tsx
@@ -455,7 +455,7 @@ export default function NetworkingTab() {
             disabledReason={
               <>
                 A network interface cannot be created or edited unless the instance is{' '}
-                {updateNicStates}.
+                {updateNicStates}
               </>
             }
           >
diff --git a/app/pages/project/instances/SettingsTab.tsx b/app/pages/project/instances/SettingsTab.tsx
index 97de07931..1a8515110 100644
--- a/app/pages/project/instances/SettingsTab.tsx
+++ b/app/pages/project/instances/SettingsTab.tsx
@@ -12,14 +12,21 @@ import { queryClient } from '@oxide/api'
 
 import { getInstanceSelector } from '~/hooks/use-params'
 
-import { AntiAffinityCard, antiAffinityGroupList } from './AntiAffinityCard'
+import {
+  allAntiAffinityGroups,
+  AntiAffinityCard,
+  instanceAntiAffinityGroups,
+} from './AntiAffinityCard'
 import { AutoRestartCard } from './AutoRestartCard'
 
 export const handle = { crumb: 'Settings' }
 
 export async function clientLoader({ params }: LoaderFunctionArgs) {
-  const instanceSelector = getInstanceSelector(params)
-  await queryClient.prefetchQuery(antiAffinityGroupList(instanceSelector))
+  const { project, instance } = getInstanceSelector(params)
+  await Promise.all([
+    queryClient.prefetchQuery(instanceAntiAffinityGroups({ project, instance })),
+    queryClient.prefetchQuery(allAntiAffinityGroups({ project })),
+  ])
   return null
 }
 
diff --git a/app/table/columns/action-col.tsx b/app/table/columns/action-col.tsx
index 6d2aab367..a782ec05f 100644
--- a/app/table/columns/action-col.tsx
+++ b/app/table/columns/action-col.tsx
@@ -42,13 +42,18 @@ export function useColsWithActions<TData extends Record<string, unknown>>(
   /** Should be static or memoized */
   columns: ColumnDef<TData, any>[], // eslint-disable-line @typescript-eslint/no-explicit-any
   /** Must be memoized to avoid re-renders */
-  makeActions: MakeActions<TData>
+  makeActions: MakeActions<TData>,
+  copyIdLabel?: string
 ) {
-  return useMemo(() => [...columns, getActionsCol(makeActions)], [columns, makeActions])
+  return useMemo(
+    () => [...columns, getActionsCol(makeActions, copyIdLabel)],
+    [columns, makeActions, copyIdLabel]
+  )
 }
 
 export const getActionsCol = <TData extends Record<string, unknown>>(
-  makeActions: MakeActions<TData>
+  makeActions: MakeActions<TData>,
+  copyIdLabel?: string
 ): ColumnDef<TData> => {
   return {
     id: 'menu',
@@ -62,7 +67,7 @@ export const getActionsCol = <TData extends Record<string, unknown>>(
       // TODO: control flow here has always confused me, would like to straighten it out
       const actions = makeActions(row.original)
       const id = typeof row.original.id === 'string' ? row.original.id : null
-      return <RowActions id={id} actions={actions} />
+      return <RowActions id={id} actions={actions} copyIdLabel={copyIdLabel} />
     },
   }
 }
diff --git a/test/e2e/anti-affinity.e2e.ts b/test/e2e/anti-affinity.e2e.ts
index 36c7bb3f5..7e2a62388 100644
--- a/test/e2e/anti-affinity.e2e.ts
+++ b/test/e2e/anti-affinity.e2e.ts
@@ -165,3 +165,70 @@ test('can delete anti-affinity group from detail page', async ({ page }) => {
   await expectRowVisible(page.getByRole('table'), { name: 'set-osiris' })
   await expect(page.getByRole('cell', { name: 'romulus-remus' })).toBeHidden()
 })
+
+test('add and remove instance from group on instance settings', async ({ page }) => {
+  const groupName = 'oil-water'
+
+  // Go to instance settings
+  await page.goto('/projects/mock-project/instances/db1/settings')
+
+  // Locate the Anti-affinity card and the table within it
+  const groupsTable = page.getByRole('table', { name: 'Anti-affinity groups' })
+
+  const groupCell = groupsTable.getByRole('cell', { name: groupName })
+
+  // Ensure the group is not initially present
+  await expect(groupCell).toBeHidden()
+
+  // Make sure Add to group button is disabled
+  const addToGroupButton = page.getByRole('button', { name: 'Add to group' })
+  await expect(addToGroupButton).toBeDisabled()
+
+  // Stop the instance
+  await page.getByRole('button', { name: 'Stop' }).click()
+  const confirmStopModal = page.getByRole('dialog', { name: 'Confirm stop' })
+  await expect(confirmStopModal).toBeVisible()
+  await confirmStopModal.getByRole('button', { name: 'Confirm' }).click()
+  await expect(confirmStopModal).toBeHidden()
+
+  // Add instance to group
+  await addToGroupButton.click()
+  const modal = page.getByRole('dialog', { name: 'Add to anti-affinity group' })
+  await expect(modal).toBeVisible()
+  await modal.getByRole('combobox', { name: 'Anti-affinity group' }).click()
+  await page.getByRole('option', { name: groupName }).click()
+  await modal.getByRole('button', { name: 'Add to group' }).click()
+  await expect(modal).toBeHidden()
+  await closeToast(page)
+
+  // Group appears in table
+  await expect(groupCell).toBeVisible()
+
+  // Go to the group page
+  await page.getByRole('link', { name: groupName }).click()
+  await expect(page.getByRole('heading', { name: groupName })).toBeVisible()
+  const groupTable = page.getByRole('table')
+
+  // Instance is listed in the group members table
+  await expectRowVisible(groupTable, { name: 'db1' })
+
+  // Go back to instance settings
+  await page.getByRole('link', { name: 'db1' }).click()
+
+  // Remove instance from group using row action
+  await clickRowAction(page, groupName, 'Remove instance from group')
+  const confirmModal = page.getByRole('dialog', { name: 'Remove instance from group' })
+  await expect(confirmModal).toBeVisible()
+  await confirmModal.getByRole('button', { name: 'Confirm' }).click()
+  await expect(confirmModal).toBeHidden()
+  await closeToast(page)
+
+  // Group is no longer in table
+  await expect(groupCell).toBeHidden()
+
+  // Instance is gone from group members table
+  await page.goto('/projects/mock-project/affinity/oil-water')
+  await expect(page.getByRole('heading', { name: groupName })).toBeVisible()
+  await expect(page.getByRole('cell', { name: 'db1' })).toBeHidden()
+  await expect(page.getByText('No group members')).toBeVisible()
+})