diff --git a/crates/asap-aware-mapping/src/replacement.rs b/crates/asap-aware-mapping/src/replacement.rs
index b69df8a33..386bd028d 100644
--- a/crates/asap-aware-mapping/src/replacement.rs
+++ b/crates/asap-aware-mapping/src/replacement.rs
@@ -358,6 +358,7 @@ use asap_types::post_asap::{
 };
 use asap_types::post_asap::{AccuracyError, CompositionOperator, GuaranteeSource, ResultGuarantee};
 use asap_types::pre_asap::agg_intent::{agg_is_mergeable, AggIntent};
+use asap_types::pre_asap::column_resolution::resolve_column_ref;
 use asap_types::pre_asap::cse::{share_common_subtrees, structural_hash, HashCache};
 use asap_types::pre_asap::expr_ir::{ArithmeticOpKind, ColumnRef};
 use asap_types::pre_asap::query_expr::any_measure_filtered;
@@ -2867,6 +2868,15 @@ fn construct_summary_agg(
         {
             // State identity is independent of which statistic reads it.
             field.name = "univmon".into();
+        } else if let (AggIntent::Quantile { .. }, SummaryInputExpr::Column(col)) =
+            (intent, &summary_input.weight)
+        {
+            // The quantile is a readout parameter: name the state after the
+            // column it summarizes, not after the query's output column.
+            let child_schema = input.child.output_schema()?;
+            if let Ok(i) = resolve_column_ref(col, &child_schema) {
+                field.name = child_schema.columns[i].name.clone();
+            }
         }
     }
 
@@ -9791,9 +9801,10 @@ mod tests {
         );
         assert_eq!(input, &SummaryUpdate::column(ColumnRef::SampleValue));
         assert_eq!(reduction, &ReductionTy::by(vec![2]));
-        // SummaryAgg edge: the state column carries the committed family.
+        // SummaryAgg edge: the state column, named after its input, carries
+        // the committed family.
         assert_eq!(
-            field(&summary_input.schema, "quantile_0_99").dtype,
+            field(&summary_input.schema, "value").dtype,
             SummaryFamilyType::Sketch(
                 SketchKind::new(SketchAlgorithm::Kll, SketchParams::Kll { k: 269 }),
                 GroupingStrategy::default()
diff --git a/crates/integration-tests/tests/promql_to_post_asap.rs b/crates/integration-tests/tests/promql_to_post_asap.rs
index 18ebd9c76..1a8d364e0 100644
--- a/crates/integration-tests/tests/promql_to_post_asap.rs
+++ b/crates/integration-tests/tests/promql_to_post_asap.rs
@@ -887,7 +887,7 @@ fn planner_heap_topk_reference_execution_matches_ground_truth() {
 ///
 /// ```text
 /// SummaryEstimate { query: Quantile{0.99} }          → {quantile_0_99: Float64}
-/// └─ SummaryAgg { Kll{k:269}, input: SampleValue }   → {quantile_0_99: Sketch(Kll, {k:269})}
+/// └─ SummaryAgg { Kll{k:269}, input: SampleValue }   → {value: Sketch(Kll, {k:269})}
 ///    └─ SummaryAgg { Rate, input: SampleValue }      → {ts, value: ExactAggregate(Rate), …}
 ///       └─ KeepPreAsap(TimeRange{5m} → Scan)         → {ts, value}
 /// ```
@@ -948,7 +948,7 @@ fn promql_quantile_of_rate_binds_kll_over_rate_accumulator() {
         "global quantile — no group keys, full reduction"
     );
     assert_eq!(
-        dtype(&summary_input.schema, "quantile_0_99"),
+        dtype(&summary_input.schema, "value"),
         &SummaryFamilyType::Sketch(
             SketchKind::new(SketchAlgorithm::Kll, SketchParams::Kll { k: 269 }),
             GroupingStrategy::default()
diff --git a/crates/planner/tests/summary_sharing.rs b/crates/planner/tests/summary_sharing.rs
index 2346537e7..c344296bf 100644
--- a/crates/planner/tests/summary_sharing.rs
+++ b/crates/planner/tests/summary_sharing.rs
@@ -267,6 +267,19 @@ async fn different_producers_are_not_shared() {
     }
 }
 
+/// Cross-series quantiles name their KLL state after the input column, not the
+/// quantile, so p50 and p99 over one selector share it.
+#[tokio::test]
+async fn cross_series_p50_and_p99_share_one_producer() {
+    let output = plan_promql(
+        &[("quantile(0.5, lat)", 0.01), ("quantile(0.99, lat)", 0.01)],
+        &CHEAP_SUMMARY,
+    )
+    .await;
+    assert!(same_states(&states(&output)));
+    assert_eq!(unique_deployments(&output), 1);
+}
+
 /// An ungrouped aggregate has no unique key, so pre-ASAP CSE keeps the two
 /// copies apart; their identical producers (rate, then sum) are shared here.
 #[tokio::test]
@@ -278,8 +291,7 @@ async fn identical_ungrouped_queries_share_their_producers() {
 }
 
 /// The SQL frontend reaches the same sharing for two copies of one filtered
-/// percentile. (Its state schema names the query's output column, so p50 and
-/// p99 over one SQL sketch are not yet structurally identical.)
+/// percentile.
 #[tokio::test]
 async fn identical_sql_percentiles_share_one_producer() {
     let query =
@@ -289,6 +301,55 @@ async fn identical_sql_percentiles_share_one_producer() {
     assert_eq!(unique_deployments(&output), 1);
 }
 
+/// The quantile is a readout parameter: SQL p50 and p99 over one filtered
+/// column build one KLL, named after its input, while each query keeps its
+/// own output column.
+#[tokio::test]
+async fn sql_p50_and_p99_share_one_producer() {
+    let p50 =
+        "SELECT approx_percentile_cont(l_extendedprice, 0.5) FROM lineitem WHERE l_orderkey > 10";
+    let p99 =
+        "SELECT approx_percentile_cont(l_extendedprice, 0.99) FROM lineitem WHERE l_orderkey > 10";
+    let output = plan_sql(&[p50, p99], &CHEAP_SUMMARY).await;
+    assert!(same_states(&states(&output)));
+    assert_eq!(unique_deployments(&output), 1);
+    let names: Vec<_> = output
+        .plans
+        .iter()
+        .map(|plan| {
+            plan.plan
+                .root
+                .schema
+                .fields
+                .iter()
+                .map(|field| field.name.clone())
+                .collect::<Vec<_>>()
+        })
+        .collect();
+    assert_eq!(
+        names,
+        [
+            ["approx_percentile_cont(lineitem.l_extendedprice,Float64(0.5))"],
+            ["approx_percentile_cont(lineitem.l_extendedprice,Float64(0.99))"],
+        ]
+    );
+
+    for queries in [
+        [
+            p50,
+            "SELECT approx_percentile_cont(l_extendedprice, 0.99) FROM lineitem WHERE l_orderkey > 20",
+        ],
+        [
+            p50,
+            "SELECT approx_percentile_cont(l_orderkey, 0.99) FROM lineitem WHERE l_orderkey > 10",
+        ],
+    ] {
+        let output = plan_sql(&queries, &CHEAP_SUMMARY).await;
+        assert!(!same_states(&states(&output)), "{queries:?}");
+        assert_eq!(unique_deployments(&output), 2, "{queries:?}");
+    }
+}
+
 /// A state costs 100 and recomputing a query costs 60 over its six reads:
 /// alone, the query recomputes raw. Shared by p50 and p99, the state costs 50
 /// per query, so both keep it.