diff --git a/src/api/schemas/v3/entities/transaction-summaries.ts b/src/api/schemas/v3/entities/transaction-summaries.ts
index c9d2ff6204..c5d875df39 100644
--- a/src/api/schemas/v3/entities/transaction-summaries.ts
+++ b/src/api/schemas/v3/entities/transaction-summaries.ts
@@ -56,6 +56,9 @@ export const BaseTransactionSummarySchema = Type.Object({
   block: BlockPositionSchema,
   bitcoin_block: BitcoinBlockPositionSchema,
   status: TransactionStatusSchema,
+  event_count: Type.Integer({
+    description: 'Number of events in the transaction',
+  }),
 });
 export type BaseTransactionSummary = Static<typeof BaseTransactionSummarySchema>;
 
diff --git a/src/api/schemas/v3/entities/transactions.ts b/src/api/schemas/v3/entities/transactions.ts
index e65009737f..4d4529ed09 100644
--- a/src/api/schemas/v3/entities/transactions.ts
+++ b/src/api/schemas/v3/entities/transactions.ts
@@ -31,9 +31,6 @@ const BaseTransactionSchema = Type.Composite([
         description: 'Only present when requested via the `include=post_conditions` query param.',
       })
     ),
-    event_count: Type.Integer({
-      description: 'Number of events in the transaction',
-    }),
     execution_cost: ExecutionCostSchema,
     vm_error: Nullable(
       Type.String({
diff --git a/src/api/serializers/v3/transactions.ts b/src/api/serializers/v3/transactions.ts
index db61b9334c..16ab34e2e0 100644
--- a/src/api/serializers/v3/transactions.ts
+++ b/src/api/serializers/v3/transactions.ts
@@ -120,6 +120,7 @@ export function serializeDbTransactionSummary(summary: DbTransactionSummary): Tr
       time_iso: unixEpochToIso(summary.burn_block_time),
     },
     status: serializeDbTransactionStatus(summary.status),
+    event_count: summary.event_count,
   };
   switch (summary.type_id) {
     case DbTxTypeId.TokenTransfer: {
@@ -241,7 +242,6 @@ export function serializeDbTransaction(
       hash: transaction.parent_block_hash,
       index_hash: transaction.parent_index_block_hash,
     },
-    event_count: transaction.event_count,
     // execution_cost_* arrive as decimal strings from Postgres (BIGINT). Coerce to ints
     // to match the response schema; v1/v2 do the same in `datastore/helpers.ts`.
     execution_cost: {
diff --git a/src/datastore/v3/constants.ts b/src/datastore/v3/constants.ts
index 5fe6d79eb0..c1aec95359 100644
--- a/src/datastore/v3/constants.ts
+++ b/src/datastore/v3/constants.ts
@@ -37,6 +37,7 @@ export const TX_SUMMARY_COLUMNS = [
   'contract_call_function_name',
   'coinbase_alt_recipient',
   'tenure_change_cause',
+  'event_count',
 ];
 
 // Heavy columns (post_conditions, raw_result, smart_contract_source_code,
@@ -46,7 +47,6 @@ export const TX_COLUMNS = [
   ...TX_SUMMARY_COLUMNS,
   'parent_block_hash',
   'parent_index_block_hash',
-  'event_count',
   'execution_cost_read_count',
   'execution_cost_read_length',
   'execution_cost_runtime',
diff --git a/src/datastore/v3/types.ts b/src/datastore/v3/types.ts
index 22919b68c9..d0cc76ccb6 100644
--- a/src/datastore/v3/types.ts
+++ b/src/datastore/v3/types.ts
@@ -51,11 +51,11 @@ export interface DbTransactionSummary extends DbTxLocation {
   contract_call_function_name: string | null;
   coinbase_alt_recipient: string | null;
   tenure_change_cause: number | null;
+  event_count: number;
 }
 
 export interface DbTransaction extends DbTransactionSummary {
   post_conditions: string;
-  event_count: number;
   execution_cost_read_count: number;
   execution_cost_read_length: number;
   execution_cost_runtime: number;
diff --git a/tests/api/blocks/block-v3.test.ts b/tests/api/blocks/block-v3.test.ts
index 0d81dd8d27..e123232155 100644
--- a/tests/api/blocks/block-v3.test.ts
+++ b/tests/api/blocks/block-v3.test.ts
@@ -118,6 +118,7 @@ describe('v3 blocks', () => {
             burn_block_time: 1000,
             tx_index: 1,
             fee_rate: 75n,
+            event_count: 2,
             type_id: DbTxTypeId.TokenTransfer,
             status: DbTxStatus.Success,
             sender_address: SENDER,
@@ -166,6 +167,7 @@ describe('v3 blocks', () => {
         },
         sponsor: null,
         fee_rate: '75',
+        event_count: 2,
         token_transfer: {
           recipient: RECIPIENT,
           amount: '100',
@@ -198,6 +200,7 @@ describe('v3 blocks', () => {
         },
         sponsor: null,
         fee_rate: '50',
+        event_count: 0,
         coinbase: {
           alt_recipient: null,
         },
diff --git a/tests/api/principal-v3/principals.test.ts b/tests/api/principal-v3/principals.test.ts
index 36d0507f6a..71c4e18d2e 100644
--- a/tests/api/principal-v3/principals.test.ts
+++ b/tests/api/principal-v3/principals.test.ts
@@ -164,6 +164,7 @@ describe('principals', () => {
           },
           sponsor: null,
           fee_rate: '50',
+          event_count: 0,
           block: {
             height: 2,
             hash: hex(2),
@@ -211,6 +212,7 @@ describe('principals', () => {
           },
           sponsor: null,
           fee_rate: '50',
+          event_count: 0,
           block: {
             height: 1,
             hash: hex(1),
diff --git a/tests/api/transactions/tx-batch-v3.test.ts b/tests/api/transactions/tx-batch-v3.test.ts
index a566642d6c..c9c456c78c 100644
--- a/tests/api/transactions/tx-batch-v3.test.ts
+++ b/tests/api/transactions/tx-batch-v3.test.ts
@@ -101,6 +101,7 @@ describe('v3 transactions batch', () => {
         .addTx({
           tx_id: TX_3,
           tx_index: 0,
+          event_count: 4,
           block_hash: '0x0002',
           index_block_hash: '0x0002',
           type_id: DbTxTypeId.Coinbase,
@@ -137,13 +138,13 @@ describe('v3 transactions batch', () => {
       body.results.map((r: { tx_id: string }) => r.tx_id),
       [TX_3, TX_1]
     );
-    // Summary shape, not full transaction: no event_count / execution_cost / post_conditions.
+    // Summary shape, not full transaction: no execution_cost / post_conditions.
     const summary = body.results[0];
     assert.equal(summary.block.height, 2);
     assert.equal(summary.sender.address, SENDER);
     assert.equal(summary.status, 'success');
     assert.equal(summary.type, 'coinbase');
-    assert.equal('event_count' in summary, false);
+    assert.equal(summary.event_count, 4);
     assert.equal('execution_cost' in summary, false);
   });
 
diff --git a/tests/api/transactions/tx-v3.test.ts b/tests/api/transactions/tx-v3.test.ts
index 40307dc943..3c0a90f609 100644
--- a/tests/api/transactions/tx-v3.test.ts
+++ b/tests/api/transactions/tx-v3.test.ts
@@ -81,6 +81,7 @@ describe('v3 transactions', () => {
             tx_id: '0x0002',
             tx_index: 0,
             fee_rate: 50n,
+            event_count: 3,
             block_hash: '0x0002',
             index_block_hash: '0x0002',
             block_time: 2000,
@@ -131,6 +132,7 @@ describe('v3 transactions', () => {
         },
         sponsor: null,
         fee_rate: '50',
+        event_count: 3,
         token_transfer: {
           recipient: 'STB44HYPYAT2BB2QE513NSP81HTMYWBJP02HPGK6',
           amount: '100',
@@ -163,6 +165,7 @@ describe('v3 transactions', () => {
         },
         sponsor: null,
         fee_rate: '50',
+        event_count: 0,
         coinbase: {
           alt_recipient: null,
         },