diff --git a/data_plane/src/storage_engines/sketch_db/schema/eviction.rs b/data_plane/src/storage_engines/sketch_db/lifecycle/eviction.rs
similarity index 99%
rename from data_plane/src/storage_engines/sketch_db/schema/eviction.rs
rename to data_plane/src/storage_engines/sketch_db/lifecycle/eviction.rs
index b982be5a..07334a56 100644
--- a/data_plane/src/storage_engines/sketch_db/schema/eviction.rs
+++ b/data_plane/src/storage_engines/sketch_db/lifecycle/eviction.rs
@@ -54,7 +54,7 @@ use tracing::{info, warn};
 
 use crate::storage_engines::sketch_db::backfill::{BackfillRegistry, BackfillStatus};
 use crate::storage_engines::sketch_db::index::SketchStore;
-use super::{AggStatus, SchemaRegistry};
+use crate::storage_engines::sketch_db::schema::{AggStatus, SchemaRegistry};
 
 /// Configuration for the eviction loop. Separate from
 /// `SchemaRegistry`'s `retirement_retention` because the service
diff --git a/data_plane/src/storage_engines/sketch_db/lifecycle/mod.rs b/data_plane/src/storage_engines/sketch_db/lifecycle/mod.rs
new file mode 100644
index 00000000..45b73c19
--- /dev/null
+++ b/data_plane/src/storage_engines/sketch_db/lifecycle/mod.rs
@@ -0,0 +1,27 @@
+//! Sid lifecycle — `Active`/`Retired`/`Expired` over per-sid metadata,
+//! eviction services, and the ingest barrier.
+//!
+//! Post-M2.3 reorg #5. The sid-level lifecycle state itself (the
+//! `retired_at_ms` / `expires_at_ms` fields on
+//! [`crate::storage_engines::sketch_db::index::SketchInstanceMetadata`],
+//! plus `force_retire` / `force_expire` / `is_writable` / `list_by_status`
+//! / `remove_instance` / `remove_instances_for_agg_config` methods on
+//! `SketchStore`) lives in `index/` next to the data it gates. This
+//! module owns the **services** that drive lifecycle transitions:
+//!
+//! - [`eviction::SchemaEvictionService`] — background tokio task that
+//!   sweeps `Expired` agg-configs (from the `SchemaRegistry`) and
+//!   removes their residual sids from `SketchStore` via
+//!   `remove_instances_for_agg_config`. Schedule-driven half of the
+//!   "controller dropped a config → its sids go away" flow.
+//!
+//! Future content:
+//! - `reconcile_from_streaming_config` — once schema/ is retired, the
+//!   "controller-reconcile-driven bulk-retire" entrypoint moves here
+//!   and operates on sids directly.
+
+pub mod eviction;
+
+pub use eviction::{
+    warn_if_retention_inverted, SchemaEvictionConfig, SchemaEvictionHandle, SchemaEvictionService,
+};
diff --git a/data_plane/src/storage_engines/sketch_db/mod.rs b/data_plane/src/storage_engines/sketch_db/mod.rs
index 7075eda8..38a7ca43 100644
--- a/data_plane/src/storage_engines/sketch_db/mod.rs
+++ b/data_plane/src/storage_engines/sketch_db/mod.rs
@@ -32,6 +32,7 @@ pub mod accuracy;
 pub mod backfill;
 pub mod data;
 pub mod index;
+pub mod lifecycle;
 pub mod metrics;
 pub mod persistence;
 pub mod query;
diff --git a/data_plane/src/storage_engines/sketch_db/schema/mod.rs b/data_plane/src/storage_engines/sketch_db/schema/mod.rs
index 13fda708..2e07a1f4 100644
--- a/data_plane/src/storage_engines/sketch_db/schema/mod.rs
+++ b/data_plane/src/storage_engines/sketch_db/schema/mod.rs
@@ -1276,8 +1276,9 @@ mod tests {
     }
 }
 
-// 2026-05 reorg: schema_eviction.rs moved alongside as a submodule.
-pub mod eviction;
-pub use eviction::{
+// Post-M2.3 reorg: eviction moved to `sketch_db::lifecycle::eviction`.
+// Legacy re-exports keep `sketch_db::schema::SchemaEvictionService` callers
+// compiling until they migrate to `sketch_db::lifecycle::*`.
+pub use crate::storage_engines::sketch_db::lifecycle::{
     warn_if_retention_inverted, SchemaEvictionConfig, SchemaEvictionHandle, SchemaEvictionService,
 };