diff --git a/esphome/components/runtime_stats/runtime_stats.h b/esphome/components/runtime_stats/runtime_stats.h
index 7299fd7315..888d48e672 100644
--- a/esphome/components/runtime_stats/runtime_stats.h
+++ b/esphome/components/runtime_stats/runtime_stats.h
@@ -42,9 +42,9 @@ class RuntimeStatsCollector {
   //   before_us = time spent in Phase A (scheduler tick) excluding time
   //               already attributed to per-component stats.
   //   tail_us   = time spent in after_component_phase_ + the trailing record/stats
-  //               prefix. On Phase A-only ticks (component phase gated) this
-  //               is just the small trailing prefix between loop_before_end_us
-  //               and loop_now_us — non-zero but typically a few µs.
+  //               prefix. Only meaningful on component-phase ticks; reported
+  //               as 0 on Phase A-only ticks (no component phase ran, so any
+  //               overhead between Phase A and stats belongs to "residual").
   // Residual overhead at log time = active − Σ(component) − before − tail,
   // which captures per-iteration inter-component bookkeeping (set_current_component,
   // WarnIfComponentBlockingGuard construction/destruction, feed_wdt_with_time calls,
diff --git a/esphome/core/application.h b/esphome/core/application.h
index e1a6109f3e..d3851a32da 100644
--- a/esphome/core/application.h
+++ b/esphome/core/application.h
@@ -649,10 +649,10 @@ inline void ESPHOME_ALWAYS_INLINE Application::loop() {
 #ifdef USE_RUNTIME_STATS
   uint32_t loop_before_end_us = micros();
   uint64_t loop_before_scheduled_us = ComponentRuntimeStats::global_recorded_us - loop_recorded_snap;
-  // Default tail_start to end-of-before so tail_us on Phase A-only ticks
-  // captures only the small gate-check + record_loop_active prefix between
-  // here and the loop_now_us sample below (not strictly zero, but tiny).
-  uint32_t loop_tail_start_us = loop_before_end_us;
+  // Only meaningful when do_component_phase is true; initialized to 0 so the
+  // tail bucket receives 0 on Phase A-only ticks (no component tail happened,
+  // the gate-check / stats-prefix overhead belongs to "residual", not "tail").
+  uint32_t loop_tail_start_us = 0;
 #endif
 
   // Gate the component phase on loop_interval_, an active high-frequency
@@ -711,8 +711,10 @@ inline void ESPHOME_ALWAYS_INLINE Application::loop() {
     uint32_t loop_before_overhead_us = loop_before_wall_us > loop_before_scheduled_us
                                            ? loop_before_wall_us - static_cast<uint32_t>(loop_before_scheduled_us)
                                            : 0;
-    global_runtime_stats->record_loop_active(loop_now_us - loop_active_start_us, loop_before_overhead_us,
-                                             loop_now_us - loop_tail_start_us);
+    // tail_us is only defined when Phase B ran; 0 on Phase A-only ticks so the
+    // stats bucket keeps its "component-phase trailing overhead" meaning.
+    uint32_t loop_tail_us = do_component_phase ? (loop_now_us - loop_tail_start_us) : 0;
+    global_runtime_stats->record_loop_active(loop_now_us - loop_active_start_us, loop_before_overhead_us, loop_tail_us);
     global_runtime_stats->process_pending_stats(now);
   }
 #endif