diff --git a/backend/app/api/v1/data_queries.py b/backend/app/api/v1/data_queries.py
new file mode 100644
index 00000000..f5a359f2
--- /dev/null
+++ b/backend/app/api/v1/data_queries.py
@@ -0,0 +1,153 @@
+import uuid
+from datetime import date
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.deps import get_current_user, get_db_session, require_study_member, require_study_roles
+from app.crud import data_query as dq_crud
+from app.crud import audit as audit_crud
+from app.crud import study as study_crud
+from app.schemas.data_query import DataQueryCreate, DataQueryRead, DataQueryUpdate
+
+router = APIRouter()
+
+
+def _is_overdue(dq: DataQueryRead) -> bool:
+    return bool(dq.due_date and date.today() > dq.due_date and dq.status != "CLOSED")
+
+
+async def _ensure_study_exists(db: AsyncSession, study_id: uuid.UUID):
+    study = await study_crud.get(db, study_id)
+    if not study:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Study not found")
+    return study
+
+
+@router.post(
+    "/",
+    response_model=DataQueryRead,
+    status_code=status.HTTP_201_CREATED,
+    dependencies=[Depends(require_study_roles(["PM", "CRA"]))],
+)
+async def create_query(
+    study_id: uuid.UUID,
+    query_in: DataQueryCreate,
+    db: AsyncSession = Depends(get_db_session),
+    current_user=Depends(get_current_user),
+) -> DataQueryRead:
+    await _ensure_study_exists(db, study_id)
+    try:
+        dq = await dq_crud.create_query(db, study_id, query_in, created_by=current_user.id)
+    except ValueError as exc:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(exc)) from exc
+    await audit_crud.log_action(
+        db,
+        study_id=study_id,
+        entity_type="data_query",
+        entity_id=dq.id,
+        action="CREATE_DATA_QUERY",
+        detail=f"DataQuery {dq.id} created",
+        operator_id=current_user.id,
+        operator_role=current_user.role,
+    )
+    obj = DataQueryRead.model_validate(dq)
+    obj.is_overdue = _is_overdue(obj)
+    return obj
+
+
+@router.get(
+    "/",
+    response_model=list[DataQueryRead],
+    dependencies=[Depends(require_study_member())],
+)
+async def list_queries(
+    study_id: uuid.UUID,
+    status_filter: str | None = None,
+    site_id: uuid.UUID | None = None,
+    subject_id: uuid.UUID | None = None,
+    assigned_to: uuid.UUID | None = None,
+    overdue: bool | None = None,
+    category: str | None = None,
+    priority: str | None = None,
+    skip: int = 0,
+    limit: int = 100,
+    db: AsyncSession = Depends(get_db_session),
+) -> list[DataQueryRead]:
+    await _ensure_study_exists(db, study_id)
+    queries = await dq_crud.list_queries(
+        db,
+        study_id,
+        status=status_filter,
+        site_id=site_id,
+        subject_id=subject_id,
+        assigned_to=assigned_to,
+        overdue=overdue,
+        category=category,
+        priority=priority,
+        skip=skip,
+        limit=limit,
+    )
+    result: list[DataQueryRead] = []
+    for q in queries:
+        obj = DataQueryRead.model_validate(q)
+        obj.is_overdue = _is_overdue(obj)
+        result.append(obj)
+    return result
+
+
+@router.get(
+    "/{query_id}",
+    response_model=DataQueryRead,
+    dependencies=[Depends(require_study_member())],
+)
+async def get_query(
+    study_id: uuid.UUID,
+    query_id: uuid.UUID,
+    db: AsyncSession = Depends(get_db_session),
+) -> DataQueryRead:
+    await _ensure_study_exists(db, study_id)
+    dq = await dq_crud.get_query(db, query_id)
+    if not dq or dq.study_id != study_id:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="DataQuery not found")
+    obj = DataQueryRead.model_validate(dq)
+    obj.is_overdue = _is_overdue(obj)
+    return obj
+
+
+@router.patch(
+    "/{query_id}",
+    response_model=DataQueryRead,
+    dependencies=[Depends(require_study_roles(["PM", "CRA"]))],
+)
+async def update_query(
+    study_id: uuid.UUID,
+    query_id: uuid.UUID,
+    query_in: DataQueryUpdate,
+    db: AsyncSession = Depends(get_db_session),
+    current_user=Depends(get_current_user),
+) -> DataQueryRead:
+    await _ensure_study_exists(db, study_id)
+    dq = await dq_crud.get_query(db, query_id)
+    if not dq or dq.study_id != study_id:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="DataQuery not found")
+    old_status = dq.status
+    updated = await dq_crud.update_query(db, dq, query_in)
+    detail = None
+    action = "UPDATE_DATA_QUERY"
+    if query_in.status and query_in.status != old_status:
+        detail = f"DataQuery {query_id} status {old_status} -> {query_in.status}"
+        action = "DATA_QUERY_STATUS_CHANGE"
+    await audit_crud.log_action(
+        db,
+        study_id=study_id,
+        entity_type="data_query",
+        entity_id=query_id,
+        action=action,
+        detail=detail or "DataQuery updated",
+        operator_id=current_user.id,
+        operator_role=current_user.role,
+    )
+    obj = DataQueryRead.model_validate(updated)
+    obj.is_overdue = _is_overdue(obj)
+    return obj
diff --git a/backend/app/api/v1/router.py b/backend/app/api/v1/router.py
index e5174483..13c689c5 100644
--- a/backend/app/api/v1/router.py
+++ b/backend/app/api/v1/router.py
@@ -1,6 +1,6 @@
 from fastapi import APIRouter
 
-from app.api.v1 import auth, users, studies, sites, members, comments, attachments, audit_logs, milestones, tasks, dashboard, subjects, visits, aes, issues
+from app.api.v1 import auth, users, studies, sites, members, comments, attachments, audit_logs, milestones, tasks, dashboard, subjects, visits, aes, issues, data_queries, verifications
 
 api_router = APIRouter()
 api_router.include_router(auth.router, prefix="/auth", tags=["auth"])
@@ -18,3 +18,5 @@ api_router.include_router(subjects.router, prefix="/studies/{study_id}/subjects"
 api_router.include_router(visits.router, prefix="/studies/{study_id}/subjects/{subject_id}/visits", tags=["visits"])
 api_router.include_router(aes.router, prefix="/studies/{study_id}/aes", tags=["aes"])
 api_router.include_router(issues.router, prefix="/studies/{study_id}/issues", tags=["issues"])
+api_router.include_router(data_queries.router, prefix="/studies/{study_id}/data-queries", tags=["data-queries"])
+api_router.include_router(verifications.router, prefix="/studies/{study_id}/verifications", tags=["verifications"])
diff --git a/backend/app/api/v1/verifications.py b/backend/app/api/v1/verifications.py
new file mode 100644
index 00000000..b643ce95
--- /dev/null
+++ b/backend/app/api/v1/verifications.py
@@ -0,0 +1,115 @@
+import uuid
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.deps import get_current_user, get_db_session, require_study_member, require_study_roles
+from app.crud import audit as audit_crud
+from app.crud import verification as verification_crud
+from app.crud import study as study_crud
+from app.schemas.verification import VerificationCreate, VerificationRead, VerificationUpdate
+
+router = APIRouter()
+
+
+async def _ensure_study_exists(db: AsyncSession, study_id: uuid.UUID):
+    study = await study_crud.get(db, study_id)
+    if not study:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Study not found")
+    return study
+
+
+@router.put(
+    "/",
+    response_model=VerificationRead,
+    status_code=status.HTTP_200_OK,
+    dependencies=[Depends(require_study_roles(["PM", "CRA"]))],
+)
+async def upsert_verification(
+    study_id: uuid.UUID,
+    payload: VerificationCreate,
+    db: AsyncSession = Depends(get_db_session),
+    current_user=Depends(get_current_user),
+) -> VerificationRead:
+    await _ensure_study_exists(db, study_id)
+    try:
+        vp = await verification_crud.upsert_progress(db, study_id, payload)
+    except ValueError as exc:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(exc)) from exc
+    await audit_crud.log_action(
+        db,
+        study_id=study_id,
+        entity_type="verification",
+        entity_id=vp.id,
+        action="UPSERT_VERIFICATION",
+        detail=f"{payload.level} progress subject {payload.subject_id} upserted",
+        operator_id=current_user.id,
+        operator_role=current_user.role,
+    )
+    return VerificationRead.model_validate(vp)
+
+
+@router.get(
+    "/",
+    response_model=list[VerificationRead],
+    dependencies=[Depends(require_study_member())],
+)
+async def list_verifications(
+    study_id: uuid.UUID,
+    site_id: uuid.UUID | None = None,
+    subject_id: uuid.UUID | None = None,
+    level: str | None = None,
+    db: AsyncSession = Depends(get_db_session),
+) -> list[VerificationRead]:
+    await _ensure_study_exists(db, study_id)
+    items = await verification_crud.list_progress(db, study_id, site_id=site_id, subject_id=subject_id, level=level)
+    return [VerificationRead.model_validate(i) for i in items]
+
+
+@router.get(
+    "/subjects/{subject_id}/{level}",
+    response_model=VerificationRead,
+    dependencies=[Depends(require_study_member())],
+)
+async def get_verification(
+    study_id: uuid.UUID,
+    subject_id: uuid.UUID,
+    level: str,
+    db: AsyncSession = Depends(get_db_session),
+) -> VerificationRead:
+    await _ensure_study_exists(db, study_id)
+    vp = await verification_crud.get_progress(db, study_id, subject_id, level)
+    if not vp:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Verification not found")
+    return VerificationRead.model_validate(vp)
+
+
+@router.patch(
+    "/{verification_id}",
+    response_model=VerificationRead,
+    dependencies=[Depends(require_study_roles(["PM", "CRA"]))],
+)
+async def update_verification(
+    study_id: uuid.UUID,
+    verification_id: uuid.UUID,
+    payload: VerificationUpdate,
+    db: AsyncSession = Depends(get_db_session),
+    current_user=Depends(get_current_user),
+) -> VerificationRead:
+    await _ensure_study_exists(db, study_id)
+    vp = await verification_crud.get_by_id(db, verification_id)
+    if not vp or vp.study_id != study_id:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Verification not found")
+
+    updated = await verification_crud.update_progress(db, vp, payload)
+    await audit_crud.log_action(
+        db,
+        study_id=study_id,
+        entity_type="verification",
+        entity_id=verification_id,
+        action="UPSERT_VERIFICATION",
+        detail=f"{updated.level} progress subject {updated.subject_id} updated",
+        operator_id=current_user.id,
+        operator_role=current_user.role,
+    )
+    return VerificationRead.model_validate(updated)
diff --git a/backend/app/crud/data_query.py b/backend/app/crud/data_query.py
new file mode 100644
index 00000000..b2803ddc
--- /dev/null
+++ b/backend/app/crud/data_query.py
@@ -0,0 +1,117 @@
+import uuid
+from datetime import date, datetime, timezone
+from typing import Sequence
+
+from sqlalchemy import select, update as sa_update
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.data_query import DataQuery
+from app.models.site import Site
+from app.models.subject import Subject
+from app.schemas.data_query import DataQueryCreate, DataQueryUpdate
+
+
+async def _validate_site_subject(db: AsyncSession, study_id: uuid.UUID, site_id: uuid.UUID | None, subject_id: uuid.UUID | None):
+    if site_id:
+        result = await db.execute(select(Site).where(Site.id == site_id))
+        site = result.scalar_one_or_none()
+        if not site or site.study_id != study_id:
+            raise ValueError("Site not found in study")
+    subject_site = None
+    if subject_id:
+        result = await db.execute(select(Subject).where(Subject.id == subject_id))
+        subj = result.scalar_one_or_none()
+        if not subj or subj.study_id != study_id:
+            raise ValueError("Subject not found in study")
+        subject_site = subj.site_id
+    if site_id and subject_site and site_id != subject_site:
+        raise ValueError("Site and subject mismatch")
+
+
+async def create_query(
+    db: AsyncSession,
+    study_id: uuid.UUID,
+    query_in: DataQueryCreate,
+    *,
+    created_by: uuid.UUID,
+) -> DataQuery:
+    await _validate_site_subject(db, study_id, query_in.site_id, query_in.subject_id)
+    dq = DataQuery(
+        study_id=study_id,
+        site_id=query_in.site_id,
+        subject_id=query_in.subject_id,
+        visit_id=query_in.visit_id,
+        title=query_in.title,
+        description=query_in.description,
+        category=query_in.category,
+        priority=query_in.priority,
+        assigned_to=query_in.assigned_to,
+        due_date=query_in.due_date,
+        status="OPEN",
+        resolution=None,
+        closed_at=None,
+        created_by=created_by,
+    )
+    db.add(dq)
+    await db.commit()
+    await db.refresh(dq)
+    return dq
+
+
+async def get_query(db: AsyncSession, query_id: uuid.UUID) -> DataQuery | None:
+    result = await db.execute(select(DataQuery).where(DataQuery.id == query_id))
+    return result.scalar_one_or_none()
+
+
+async def list_queries(
+    db: AsyncSession,
+    study_id: uuid.UUID,
+    *,
+    status: str | None = None,
+    site_id: uuid.UUID | None = None,
+    subject_id: uuid.UUID | None = None,
+    assigned_to: uuid.UUID | None = None,
+    overdue: bool | None = None,
+    category: str | None = None,
+    priority: str | None = None,
+    skip: int = 0,
+    limit: int = 100,
+) -> Sequence[DataQuery]:
+    stmt = select(DataQuery).where(DataQuery.study_id == study_id)
+    if status:
+        stmt = stmt.where(DataQuery.status == status)
+    if site_id:
+        stmt = stmt.where(DataQuery.site_id == site_id)
+    if subject_id:
+        stmt = stmt.where(DataQuery.subject_id == subject_id)
+    if assigned_to:
+        stmt = stmt.where(DataQuery.assigned_to == assigned_to)
+    if category:
+        stmt = stmt.where(DataQuery.category == category)
+    if priority:
+        stmt = stmt.where(DataQuery.priority == priority)
+    if overdue is True:
+        stmt = stmt.where(DataQuery.due_date < date.today(), DataQuery.status != "CLOSED")
+    if overdue is False:
+        stmt = stmt.where((DataQuery.due_date >= date.today()) | (DataQuery.due_date.is_(None)) | (DataQuery.status == "CLOSED"))
+    stmt = stmt.offset(skip).limit(limit)
+    result = await db.execute(stmt)
+    return result.scalars().all()
+
+
+async def update_query(db: AsyncSession, dq: DataQuery, dq_in: DataQueryUpdate) -> DataQuery:
+    update_data = dq_in.model_dump(exclude_unset=True)
+    if "status" in update_data:
+        if update_data["status"] == "CLOSED":
+            update_data["closed_at"] = datetime.now(timezone.utc)
+        else:
+            update_data["closed_at"] = None
+    if update_data:
+        await db.execute(
+            sa_update(DataQuery)
+            .where(DataQuery.id == dq.id)
+            .values(**update_data)
+        )
+        await db.commit()
+    await db.refresh(dq)
+    return dq
diff --git a/backend/app/crud/verification.py b/backend/app/crud/verification.py
new file mode 100644
index 00000000..abe73eeb
--- /dev/null
+++ b/backend/app/crud/verification.py
@@ -0,0 +1,108 @@
+import uuid
+from datetime import date
+from typing import Sequence
+
+from sqlalchemy import select, update as sa_update
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.subject import Subject
+from app.models.verification import VerificationProgress
+from app.schemas.verification import VerificationCreate, VerificationUpdate
+
+
+async def _validate_site_subject(db: AsyncSession, study_id: uuid.UUID, site_id: uuid.UUID, subject_id: uuid.UUID):
+    result = await db.execute(select(Subject).where(Subject.id == subject_id))
+    subj = result.scalar_one_or_none()
+    if not subj or subj.study_id != study_id:
+        raise ValueError("Subject not found in study")
+    if subj.site_id != site_id:
+        raise ValueError("Site does not match subject")
+
+
+async def upsert_progress(
+    db: AsyncSession,
+    study_id: uuid.UUID,
+    data: VerificationCreate,
+) -> VerificationProgress:
+    await _validate_site_subject(db, study_id, data.site_id, data.subject_id)
+
+    result = await db.execute(
+        select(VerificationProgress).where(
+            VerificationProgress.study_id == study_id,
+            VerificationProgress.subject_id == data.subject_id,
+            VerificationProgress.level == data.level,
+        )
+    )
+    existing = result.scalar_one_or_none()
+    if existing:
+        update_data = data.model_dump()
+        await db.execute(
+            sa_update(VerificationProgress)
+            .where(VerificationProgress.id == existing.id)
+            .values(**update_data)
+        )
+        await db.commit()
+        await db.refresh(existing)
+        return existing
+
+    vp = VerificationProgress(
+        study_id=study_id,
+        site_id=data.site_id,
+        subject_id=data.subject_id,
+        level=data.level,
+        percent=data.percent,
+        last_verified_at=data.last_verified_at,
+        verifier_id=data.verifier_id,
+        notes=data.notes,
+    )
+    db.add(vp)
+    await db.commit()
+    await db.refresh(vp)
+    return vp
+
+
+async def get_progress(db: AsyncSession, study_id: uuid.UUID, subject_id: uuid.UUID, level: str) -> VerificationProgress | None:
+    result = await db.execute(
+        select(VerificationProgress).where(
+            VerificationProgress.study_id == study_id,
+            VerificationProgress.subject_id == subject_id,
+            VerificationProgress.level == level,
+        )
+    )
+    return result.scalar_one_or_none()
+
+
+async def get_by_id(db: AsyncSession, verification_id: uuid.UUID) -> VerificationProgress | None:
+    result = await db.execute(select(VerificationProgress).where(VerificationProgress.id == verification_id))
+    return result.scalar_one_or_none()
+
+
+async def list_progress(
+    db: AsyncSession,
+    study_id: uuid.UUID,
+    site_id: uuid.UUID | None = None,
+    subject_id: uuid.UUID | None = None,
+    level: str | None = None,
+) -> Sequence[VerificationProgress]:
+    stmt = select(VerificationProgress).where(VerificationProgress.study_id == study_id)
+    if site_id:
+        stmt = stmt.where(VerificationProgress.site_id == site_id)
+    if subject_id:
+        stmt = stmt.where(VerificationProgress.subject_id == subject_id)
+    if level:
+        stmt = stmt.where(VerificationProgress.level == level)
+    result = await db.execute(stmt)
+    return result.scalars().all()
+
+
+async def update_progress(db: AsyncSession, vp: VerificationProgress, data: VerificationUpdate) -> VerificationProgress:
+    update_data = data.model_dump(exclude_unset=True)
+    if update_data:
+        await db.execute(
+            sa_update(VerificationProgress)
+            .where(VerificationProgress.id == vp.id)
+            .values(**update_data)
+        )
+        await db.commit()
+    await db.refresh(vp)
+    return vp
diff --git a/backend/app/db/base.py b/backend/app/db/base.py
index a1aeb9dd..8a18a1c3 100644
--- a/backend/app/db/base.py
+++ b/backend/app/db/base.py
@@ -14,3 +14,5 @@ from app.models.subject import Subject  # noqa: F401
 from app.models.visit import Visit  # noqa: F401
 from app.models.ae import AdverseEvent  # noqa: F401
 from app.models.issue import Issue  # noqa: F401
+from app.models.data_query import DataQuery  # noqa: F401
+from app.models.verification import VerificationProgress  # noqa: F401
diff --git a/backend/app/models/data_query.py b/backend/app/models/data_query.py
new file mode 100644
index 00000000..135f5bce
--- /dev/null
+++ b/backend/app/models/data_query.py
@@ -0,0 +1,32 @@
+import uuid
+from datetime import datetime, date
+
+from sqlalchemy import Date, DateTime, ForeignKey, String, Text, func
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.db.base_class import Base
+
+
+class DataQuery(Base):
+    __tablename__ = "data_queries"
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    study_id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("studies.id"), index=True, nullable=False)
+    site_id: Mapped[uuid.UUID | None] = mapped_column(UUID(as_uuid=True), ForeignKey("sites.id"), index=True, nullable=True)
+    subject_id: Mapped[uuid.UUID | None] = mapped_column(UUID(as_uuid=True), ForeignKey("subjects.id"), index=True, nullable=True)
+    visit_id: Mapped[uuid.UUID | None] = mapped_column(UUID(as_uuid=True), nullable=True)
+    title: Mapped[str] = mapped_column(String(255), nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    category: Mapped[str] = mapped_column(String(50), nullable=False)
+    priority: Mapped[str] = mapped_column(String(20), nullable=False)
+    assigned_to: Mapped[uuid.UUID | None] = mapped_column(UUID(as_uuid=True), ForeignKey("users.id"), nullable=True)
+    due_date: Mapped[date | None] = mapped_column(Date, nullable=True)
+    status: Mapped[str] = mapped_column(String(20), nullable=False, default="OPEN")
+    resolution: Mapped[str | None] = mapped_column(Text, nullable=True)
+    closed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+    created_by: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("users.id"), nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
+    )
diff --git a/backend/app/models/verification.py b/backend/app/models/verification.py
new file mode 100644
index 00000000..6802b1b2
--- /dev/null
+++ b/backend/app/models/verification.py
@@ -0,0 +1,27 @@
+import uuid
+from datetime import datetime, date
+
+from sqlalchemy import Date, DateTime, ForeignKey, Integer, String, Text, UniqueConstraint, func
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.db.base_class import Base
+
+
+class VerificationProgress(Base):
+    __tablename__ = "verification_progress"
+    __table_args__ = (UniqueConstraint("study_id", "subject_id", "level", name="uq_verification_subject_level"),)
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    study_id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("studies.id"), index=True, nullable=False)
+    site_id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("sites.id"), index=True, nullable=False)
+    subject_id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("subjects.id"), index=True, nullable=False)
+    level: Mapped[str] = mapped_column(String(10), nullable=False)  # SDR / SDV
+    percent: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+    last_verified_at: Mapped[date | None] = mapped_column(Date, nullable=True)
+    verifier_id: Mapped[uuid.UUID | None] = mapped_column(UUID(as_uuid=True), ForeignKey("users.id"), nullable=True)
+    notes: Mapped[str | None] = mapped_column(Text, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False, server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
+    )
diff --git a/backend/app/schemas/data_query.py b/backend/app/schemas/data_query.py
new file mode 100644
index 00000000..0d44b183
--- /dev/null
+++ b/backend/app/schemas/data_query.py
@@ -0,0 +1,51 @@
+import uuid
+from datetime import date, datetime
+from typing import Optional
+
+from pydantic import BaseModel, ConfigDict
+
+
+class DataQueryCreate(BaseModel):
+    title: str
+    description: Optional[str] = None
+    category: str
+    priority: str
+    site_id: Optional[uuid.UUID] = None
+    subject_id: Optional[uuid.UUID] = None
+    visit_id: Optional[uuid.UUID] = None
+    assigned_to: Optional[uuid.UUID] = None
+    due_date: Optional[date] = None
+
+
+class DataQueryUpdate(BaseModel):
+    title: Optional[str] = None
+    description: Optional[str] = None
+    category: Optional[str] = None
+    priority: Optional[str] = None
+    assigned_to: Optional[uuid.UUID] = None
+    due_date: Optional[date] = None
+    status: Optional[str] = None
+    resolution: Optional[str] = None
+
+
+class DataQueryRead(BaseModel):
+    id: uuid.UUID
+    study_id: uuid.UUID
+    site_id: Optional[uuid.UUID]
+    subject_id: Optional[uuid.UUID]
+    visit_id: Optional[uuid.UUID]
+    title: str
+    description: Optional[str]
+    category: str
+    priority: str
+    assigned_to: Optional[uuid.UUID]
+    due_date: Optional[date]
+    status: str
+    resolution: Optional[str]
+    closed_at: Optional[datetime]
+    created_by: uuid.UUID
+    created_at: datetime
+    updated_at: datetime
+    is_overdue: bool | None = None
+
+    model_config = ConfigDict(from_attributes=True)
diff --git a/backend/app/schemas/verification.py b/backend/app/schemas/verification.py
new file mode 100644
index 00000000..587c21bf
--- /dev/null
+++ b/backend/app/schemas/verification.py
@@ -0,0 +1,38 @@
+import uuid
+from datetime import date, datetime
+from typing import Optional
+
+from pydantic import BaseModel, ConfigDict, Field
+
+
+class VerificationCreate(BaseModel):
+    site_id: uuid.UUID
+    subject_id: uuid.UUID
+    level: str
+    percent: int = Field(ge=0, le=100)
+    last_verified_at: Optional[date] = None
+    verifier_id: Optional[uuid.UUID] = None
+    notes: Optional[str] = None
+
+
+class VerificationUpdate(BaseModel):
+    percent: Optional[int] = Field(default=None, ge=0, le=100)
+    last_verified_at: Optional[date] = None
+    verifier_id: Optional[uuid.UUID] = None
+    notes: Optional[str] = None
+
+
+class VerificationRead(BaseModel):
+    id: uuid.UUID
+    study_id: uuid.UUID
+    site_id: uuid.UUID
+    subject_id: uuid.UUID
+    level: str
+    percent: int
+    last_verified_at: Optional[date]
+    verifier_id: Optional[uuid.UUID]
+    notes: Optional[str]
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = ConfigDict(from_attributes=True)
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