diff --git a/backend/src/cyclone/api.py b/backend/src/cyclone/api.py
index 78837dd..7e558ca 100644
--- a/backend/src/cyclone/api.py
+++ b/backend/src/cyclone/api.py
@@ -32,6 +32,7 @@ from pydantic import ValidationError
 
 from cyclone import __version__, db
 from cyclone.db import Claim, ClaimState, Remittance
+from sqlalchemy import desc, or_
 from cyclone.inbox_state import apply_999_rejections
 from cyclone.inbox_state_277ca import apply_277ca_rejections
 from cyclone.audit_log import AuditEvent, append_event, verify_chain
@@ -2934,7 +2935,73 @@ def get_configured_provider(npi: str):
     p = store.get_provider(npi)
     if p is None:
         raise HTTPException(status_code=404, detail=f"provider {npi!r} not found")
-    return json.loads(p.model_dump_json())
+    provider_dict = json.loads(p.model_dump_json())
+
+    # SP21 Task 1.6: extend the response with two top-N arrays that the
+    # drill-down peek panel hangs off. ``recent_claims`` reuses the
+    # existing store projection (already returns UI-shaped dicts with
+    # ``submissionDate``); ``recent_activity`` is a direct ORM join
+    # because ``ActivityEvent`` has no ``provider_npi`` column — the
+    # filter has to hop through ``Claim.id``.
+    recent_claims = sorted(
+        store.iter_claims(provider_npi=npi),
+        key=lambda c: c.get("submissionDate") or "",
+        reverse=True,
+    )[:10]
+
+    # Activity filter has TWO join paths back to a Claim for this
+    # provider:
+    #   1. ``ActivityEvent.claim_id IN (claim_ids)`` — events that were
+    #      recorded with a claim FK already set (claim_submitted,
+    #      manual_match, claim_paid, etc.).
+    #   2. ``Remittance.claim_id IN (claim_ids)`` — the original
+    #      ``remit_received`` event recorded at 835 ingest time
+    #      (``store.add`` lines 999-1003) is inserted with
+    #      ``claim_id=None`` because the remittance hasn't been matched
+    #      to a claim yet. The auto-reconcile pass later sets
+    #      ``Remittance.claim_id`` (``reconcile.run`` lines 289-293),
+    #      but the *original* ActivityEvent row stays orphaned. The
+    #      outer-join-then-OR lets us surface both shapes. Without
+    #      path 2, a provider's activity feed looks frozen the moment
+    #      an 835 lands — the most common activity, invisible.
+    with db.SessionLocal()() as s:
+        claim_ids = [
+            cid
+            for (cid,) in s.query(Claim.id)
+            .filter(Claim.provider_npi == npi)
+            .all()
+        ]
+        activity_rows = []
+        if claim_ids:
+            activity_rows = (
+                s.query(db.ActivityEvent)
+                .outerjoin(
+                    Remittance,
+                    db.ActivityEvent.remittance_id == Remittance.id,
+                )
+                .filter(or_(
+                    db.ActivityEvent.claim_id.in_(claim_ids),
+                    Remittance.claim_id.in_(claim_ids),
+                ))
+                .order_by(desc(db.ActivityEvent.ts))
+                .limit(10)
+                .all()
+            )
+
+    def _activity_to_ui(a):
+        return {
+            "id": a.id,
+            "ts": a.ts.isoformat().replace("+00:00", "Z") if a.ts else "",
+            "kind": a.kind,
+            "batchId": a.batch_id,
+            "claimId": a.claim_id,
+            "remittanceId": a.remittance_id,
+            "payload": a.payload_json or {},
+        }
+
+    provider_dict["recent_claims"] = recent_claims
+    provider_dict["recent_activity"] = [_activity_to_ui(a) for a in activity_rows]
+    return provider_dict
 
 
 @app.get("/api/config/payers")
diff --git a/backend/tests/test_provider_extended_response.py b/backend/tests/test_provider_extended_response.py
new file mode 100644
index 0000000..400381d
--- /dev/null
+++ b/backend/tests/test_provider_extended_response.py
@@ -0,0 +1,177 @@
+"""Tests for the extended GET /api/config/providers/{npi} (SP21 Task 1.6).
+
+The endpoint gains two new top-level arrays for the drill-down panel:
+``recent_claims`` (top 10 by submission date desc) and ``recent_activity``
+(top 10 by ``ts`` desc, joined to claims by ``claim_id`` because
+``ActivityEvent`` has no direct ``provider_npi`` column).
+
+Existing SP9 fields (``label``, ``legal_name``, ``tax_id``,
+``address_line1``, ``city``, ``state``, ``zip``, etc.) must remain
+present — the new arrays are additive only.
+
+The fixtures in ``fixtures/minimal_837p.txt`` and ``fixtures/minimal_835.txt``
+pair up to a single claim with ``provider_npi='1993999998'``. That NPI is
+NOT in the seeded provider set (Montrose/Delta/Salida → 1881068062/1851446637/
+1467507269). For the tests we hit the seeded Montrose NPI, which is the
+canonical SP9 fixture NPI. The arrays come back as empty lists — the
+contract under test is the *shape* (array, ≤10) and the *backwards compat*
+of the existing fields; the data-path itself is exercised by the existing
+ingestion path that backs ``/api/claims``.
+"""
+from __future__ import annotations
+
+from datetime import datetime, timezone
+from pathlib import Path
+
+import pytest
+from fastapi.testclient import TestClient
+
+from cyclone.api import app
+from cyclone.providers import Provider
+from cyclone.store import store
+
+FIXTURE_837 = Path(__file__).parent / "fixtures" / "minimal_837p.txt"
+FIXTURE_835 = Path(__file__).parent / "fixtures" / "minimal_835.txt"
+
+# Montrose — one of the three providers that `ensure_clearhouse_seeded()`
+# writes into the providers table. Using a seeded NPI means the endpoint
+# won't 404; the seeded claims (provider_npi='1993999998') won't appear
+# under this NPI, so recent_claims/activity are expected empty lists.
+MONTROSE_NPI = "1881068062"
+
+# NPI the minimal 837P fixture bills under. NOT in the default seed —
+# registering it before ingest is required to pass R204 (NPI must exist
+# in the providers table).
+TEST_837_NPI = "1993999998"
+
+
+@pytest.fixture
+def client() -> TestClient:
+    return TestClient(app)
+
+
+@pytest.fixture
+def seeded_db(client: TestClient):
+    """Seed the clearhouse + ingest the minimal 837P/835 fixtures.
+
+    Mirrors the Task 1.5 ``seeded_db`` pattern: seed → ingest → hand the
+    client back so the test hits the same TestClient.
+
+    The 837 fixture bills under ``TEST_837_NPI``; without first registering
+    that provider the parser's R204 rule rejects the claim with HTTP 422.
+    """
+    store.ensure_clearhouse_seeded()
+    test_provider = Provider(
+        npi=TEST_837_NPI,
+        label="Test Provider",
+        legal_name="Test Provider Inc",
+        tax_id="123456789",
+        taxonomy_code="207R00000X",
+        address_line1="123 Test St",
+        city="Denver",
+        state="CO",
+        zip="80202",
+        created_at=datetime.now(timezone.utc),
+        updated_at=datetime.now(timezone.utc),
+    )
+    store.upsert_provider(test_provider)
+    text_837 = FIXTURE_837.read_text()
+    text_835 = FIXTURE_835.read_text()
+    r837 = client.post(
+        "/api/parse-837",
+        files={"file": ("x.txt", text_837, "text/plain")},
+        headers={"Accept": "application/json"},
+    )
+    assert r837.status_code == 200, r837.text
+    r835 = client.post(
+        "/api/parse-835",
+        files={"file": ("era.txt", text_835, "text/plain")},
+        headers={"Accept": "application/json"},
+    )
+    assert r835.status_code == 200, r835.text
+    return client
+
+
+def test_provider_detail_includes_recent_claims(seeded_db: TestClient):
+    """The extended response gains a recent_claims array (top 10)."""
+    resp = seeded_db.get(f"/api/config/providers/{MONTROSE_NPI}")
+    assert resp.status_code == 200, resp.text
+    data = resp.json()
+    assert "recent_claims" in data
+    assert isinstance(data["recent_claims"], list)
+    assert len(data["recent_claims"]) <= 10
+
+
+def test_provider_detail_includes_recent_activity(seeded_db: TestClient):
+    """The extended response gains a recent_activity array (top 10)."""
+    resp = seeded_db.get(f"/api/config/providers/{MONTROSE_NPI}")
+    assert resp.status_code == 200, resp.text
+    data = resp.json()
+    assert "recent_activity" in data
+    assert isinstance(data["recent_activity"], list)
+    assert len(data["recent_activity"]) <= 10
+
+
+def test_provider_detail_backwards_compat(seeded_db: TestClient):
+    """All SP9 fields still present; new arrays don't break the contract.
+
+    The Provider Pydantic model (backend/src/cyclone/providers.py)
+    serializes snake_case fields — that's what the wire carries. The
+    TS ``Provider`` interface in ``src/types/index.ts`` is the
+    in-memory sample shape and intentionally diverges; the contract
+    being verified here is the API's actual payload.
+    """
+    resp = seeded_db.get(f"/api/config/providers/{MONTROSE_NPI}")
+    assert resp.status_code == 200, resp.text
+    data = resp.json()
+    for key in (
+        "npi",
+        "label",
+        "legal_name",
+        "tax_id",
+        "taxonomy_code",
+        "address_line1",
+        "city",
+        "state",
+        "zip",
+        "is_active",
+    ):
+        assert key in data, f"missing field {key}"
+
+
+def test_provider_detail_includes_orphan_remit_received(seeded_db: TestClient):
+    """Regression: the ``remit_received`` ActivityEvent is recorded at 835
+    ingest with ``claim_id=None`` (``store.add`` lines 999-1003) — the
+    remittance hasn't been matched to a claim yet. The original
+    ``ActivityEvent.claim_id IN (claim_ids)`` filter misses it because
+    the orphan's claim_id is NULL.
+
+    Once reconciliation (auto or manual) populates
+    ``Remittance.claim_id``, the activity filter must surface the event
+    via the ``Remittance.claim_id IN (claim_ids)`` branch of the OR.
+    Without that branch, a provider's activity feed appears to freeze
+    the moment an 835 lands — the most common activity, invisible.
+
+    Setup: ingest 837+835 for ``TEST_837_NPI`` (claim CLM001 + remit
+    CLM001), then manually match them so ``Remittance.claim_id`` is
+    populated. The bug presents as: only ``claim_submitted`` and
+    ``manual_match`` appear (no ``remit_received``). The fix surfaces
+    all three.
+    """
+    # Force the match — simulates the post-reconciliation state that
+    # populate Remittance.claim_id without depending on auto-reconcile
+    # heuristics (which don't match this minimal fixture).
+    match_resp = seeded_db.post(
+        "/api/reconciliation/match",
+        json={"claim_id": "CLM001", "remit_id": "CLM001"},
+    )
+    assert match_resp.status_code == 200, match_resp.text
+
+    resp = seeded_db.get(f"/api/config/providers/{TEST_837_NPI}")
+    assert resp.status_code == 200, resp.text
+    data = resp.json()
+    kinds = {event["kind"] for event in data["recent_activity"]}
+    assert "remit_received" in kinds, (
+        f"expected remit_received in recent_activity (orphan remits "
+        f"must surface via the Remittance join), got kinds={sorted(kinds)}"
+    )
diff --git a/src/types/index.ts b/src/types/index.ts
index bc2c01a..c48a4d8 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -50,6 +50,58 @@ export interface Provider {
   phone: string;
   claimCount: number;
   outstandingAr: number;
+  /**
+   * SP21 Task 1.6: populated by the extended `GET /api/config/providers/{npi}`
+   * endpoint. Top 10 claims for this provider by `submissionDate` desc.
+   * Optional so legacy callers (in-memory sample data) keep working
+   * without an API round-trip.
+   */
+  recent_claims?: ClaimSummary[];
+  /**
+   * SP21 Task 1.6: populated by the extended `GET /api/config/providers/{npi}`
+   * endpoint. Top 10 activity events (by `ts` desc) joined to claims
+   * owned by this provider via `claim_id`.
+   */
+  recent_activity?: ActivityEvent[];
+}
+
+/**
+ * SP21 Task 1.6: slim claim projection returned by
+ * `GET /api/config/providers/{npi}.recent_claims`. Mirrors the wire
+ * shape of `store.iter_claims(provider_npi=...)` 1:1 (camelCase,
+ * superset of the legacy `Claim` interface).
+ */
+export interface ClaimSummary {
+  id: string;
+  state: string;
+  billedAmount: number;
+  patientName: string;
+  providerNpi: string;
+  payerName: string;
+  cptCode: string;
+  submissionDate: string;
+  parsedAt: string;
+  status: string;
+  matchedRemittanceId?: string | null;
+  batchId: string;
+  receivedAmount?: number;
+  denialReason?: string | null;
+}
+
+/**
+ * SP21 Task 1.6: one row in `recent_activity`. Mirrors the Python
+ * ORM `ActivityEvent` (snake_case fields rewritten to camelCase for
+ * the wire). `payload` carries the same dict the recorder wrote at
+ * the time of the event (message, npi, amount, etc.).
+ */
+export interface ActivityEvent {
+  id: number;
+  ts: string; // ISO Z
+  kind: string;
+  batchId: string | null;
+  claimId: string | null;
+  remittanceId: string | null;
+  payload: Record<string, unknown>;
 }
 
 export interface Remittance {