diff --git a/core/src/banking_stage/qos_service.rs b/core/src/banking_stage/qos_service.rs
index 8c1507ae3fb91c..c9e1d98d64822e 100644
--- a/core/src/banking_stage/qos_service.rs
+++ b/core/src/banking_stage/qos_service.rs
@@ -120,6 +120,7 @@ impl QosService {
                 }
             })
             .collect();
+        cost_tracker.add_transactions_in_flight(num_included);
 
         cost_tracking_time.stop();
         self.metrics
@@ -167,17 +168,20 @@ impl QosService {
         bank: &Bank,
     ) {
         let mut cost_tracker = bank.write_cost_tracker().unwrap();
+        let mut num_included = 0;
         transaction_cost_results
             .zip(transaction_committed_status)
             .for_each(|(tx_cost, transaction_committed_details)| {
                 // Only transactions that the qos service included have to be
                 // checked for update
                 if let Ok(tx_cost) = tx_cost {
+                    num_included += 1;
                     if *transaction_committed_details == CommitTransactionDetails::NotCommitted {
                         cost_tracker.remove(tx_cost)
                     }
                 }
             });
+        cost_tracker.sub_transactions_in_flight(num_included);
     }
 
     fn update_committed_transaction_costs<'a>(
@@ -206,13 +210,16 @@ impl QosService {
         bank: &Bank,
     ) {
         let mut cost_tracker = bank.write_cost_tracker().unwrap();
+        let mut num_included = 0;
         transaction_cost_results.for_each(|tx_cost| {
             // Only transactions that the qos service included have to be
             // removed
             if let Ok(tx_cost) = tx_cost {
+                num_included += 1;
                 cost_tracker.remove(tx_cost);
             }
         });
+        cost_tracker.sub_transactions_in_flight(num_included);
     }
 
     // metrics are reported by bank slot
diff --git a/core/src/cost_update_service.rs b/core/src/cost_update_service.rs
index 6b49c8fdf1db46..58ef6c48ed7721 100644
--- a/core/src/cost_update_service.rs
+++ b/core/src/cost_update_service.rs
@@ -7,6 +7,7 @@ use {
     std::{
         sync::Arc,
         thread::{self, Builder, JoinHandle},
+        time::Duration,
     },
 };
 pub enum CostUpdate {
@@ -19,6 +20,12 @@ pub struct CostUpdateService {
     thread_hdl: JoinHandle<()>,
 }
 
+// The maximum number of retries to check if CostTracker::in_flight_transaction_count() has settled
+// to zero. Bail out after this many retries; the in-flight count is reported so this is ok
+const MAX_LOOP_COUNT: usize = 25;
+// Throttle checking the count to avoid excessive polling
+const LOOP_LIMITER: Duration = Duration::from_millis(10);
+
 impl CostUpdateService {
     pub fn new(blockstore: Arc<Blockstore>, cost_update_receiver: CostUpdateReceiver) -> Self {
         let thread_hdl = Builder::new()
@@ -39,7 +46,28 @@ impl CostUpdateService {
         for cost_update in cost_update_receiver.iter() {
             match cost_update {
                 CostUpdate::FrozenBank { bank } => {
-                    bank.read_cost_tracker().unwrap().report_stats(bank.slot());
+                    for loop_count in 1..=MAX_LOOP_COUNT {
+                        {
+                            // Release the lock so that the thread that will
+                            // update the count is able to obtain a write lock
+                            //
+                            // Use inner scope to avoid sleeping with the lock
+                            let cost_tracker = bank.read_cost_tracker().unwrap();
+                            let in_flight_transaction_count =
+                                cost_tracker.in_flight_transaction_count();
+
+                            if in_flight_transaction_count == 0 || loop_count == MAX_LOOP_COUNT {
+                                let slot = bank.slot();
+                                trace!(
+                                    "inflight transaction count is {in_flight_transaction_count} \
+                                    for slot {slot} after {loop_count} iteration(s)"
+                                );
+                                cost_tracker.report_stats(slot);
+                                break;
+                            }
+                        }
+                        std::thread::sleep(LOOP_LIMITER);
+                    }
                 }
             }
         }
diff --git a/cost-model/src/cost_tracker.rs b/cost-model/src/cost_tracker.rs
index b5e3f9f4932a59..64185edb6c77ca 100644
--- a/cost-model/src/cost_tracker.rs
+++ b/cost-model/src/cost_tracker.rs
@@ -61,6 +61,10 @@ pub struct CostTracker {
     transaction_signature_count: u64,
     secp256k1_instruction_signature_count: u64,
     ed25519_instruction_signature_count: u64,
+    /// The number of transactions that have had their estimated cost added to
+    /// the tracker, but are still waiting for an update with actual usage or
+    /// removal if the transaction does not end up getting committed.
+    in_flight_transaction_count: usize,
 }
 
 impl Default for CostTracker {
@@ -83,6 +87,7 @@ impl Default for CostTracker {
             transaction_signature_count: 0,
             secp256k1_instruction_signature_count: 0,
             ed25519_instruction_signature_count: 0,
+            in_flight_transaction_count: 0,
         }
     }
 }
@@ -100,6 +105,23 @@ impl CostTracker {
         self.vote_cost_limit = vote_cost_limit;
     }
 
+    pub fn in_flight_transaction_count(&self) -> usize {
+        self.in_flight_transaction_count
+    }
+
+    pub fn add_transactions_in_flight(&mut self, in_flight_transaction_count: usize) {
+        saturating_add_assign!(
+            self.in_flight_transaction_count,
+            in_flight_transaction_count
+        );
+    }
+
+    pub fn sub_transactions_in_flight(&mut self, in_flight_transaction_count: usize) {
+        self.in_flight_transaction_count = self
+            .in_flight_transaction_count
+            .saturating_sub(in_flight_transaction_count);
+    }
+
     pub fn try_add(&mut self, tx_cost: &TransactionCost) -> Result<u64, CostTrackerError> {
         self.would_fit(tx_cost)?;
         self.add_transaction_cost(tx_cost);
@@ -174,6 +196,11 @@ impl CostTracker {
                 self.ed25519_instruction_signature_count,
                 i64
             ),
+            (
+                "inflight_transaction_count",
+                self.in_flight_transaction_count,
+                i64
+            ),
         );
     }