diff --git a/lib/datadog/ci/ext/test.rb b/lib/datadog/ci/ext/test.rb
index 0d219b96..ecb184a5 100644
--- a/lib/datadog/ci/ext/test.rb
+++ b/lib/datadog/ci/ext/test.rb
@@ -26,6 +26,7 @@ module Test
         # ITR tags
         TAG_ITR_TEST_SKIPPING_ENABLED = "test.itr.tests_skipping.enabled"
         TAG_ITR_TEST_SKIPPING_TYPE = "test.itr.tests_skipping.type"
+        TAG_ITR_SKIPPED_BY_ITR = "test.itr.skipped_by_itr"
 
         # Code coverage tags
         TAG_CODE_COVERAGE_ENABLED = "test.code_coverage.enabled"
diff --git a/lib/datadog/ci/itr/runner.rb b/lib/datadog/ci/itr/runner.rb
index 44d72877..7e8ac877 100644
--- a/lib/datadog/ci/itr/runner.rb
+++ b/lib/datadog/ci/itr/runner.rb
@@ -2,6 +2,8 @@
 
 require "pp"
 
+require "datadog/core/utils/forking"
+
 require_relative "../ext/test"
 require_relative "../ext/transport"
 
@@ -19,7 +21,9 @@ module ITR
       # Integrates with backend to provide test impact analysis data and
       # skip tests that are not impacted by the changes
       class Runner
-        attr_reader :correlation_id, :skippable_tests
+        include Core::Utils::Forking
+
+        attr_reader :correlation_id, :skippable_tests, :skipped_tests_count
 
         def initialize(
           dd_env:,
@@ -39,6 +43,9 @@ def initialize(
           @correlation_id = nil
           @skippable_tests = []
 
+          @skipped_tests_count = 0
+          @mutex = Mutex.new
+
           Datadog.logger.debug("ITR Runner initialized with enabled: #{@enabled}")
         end
 
@@ -113,6 +120,32 @@ def stop_coverage(test)
           event
         end
 
+        def mark_if_skippable(test)
+          return unless enabled? && skipping_tests?
+
+          test_full_name = Utils::TestRun.test_full_name(test.name, test.test_suite_name)
+
+          if @skippable_tests.include?(test_full_name)
+            test.set_tag(Ext::Test::TAG_ITR_SKIPPED_BY_ITR, "true")
+            increment_skipped_tests_counter
+
+            Datadog.logger.debug { "Marked test as skippable: #{test_full_name}" }
+          else
+            Datadog.logger.debug { "Test is not skippable: #{test_full_name}" }
+          end
+        end
+
+        def increment_skipped_tests_counter
+          if forked?
+            Datadog.logger.warn { "ITR is not supported for forking test runners yet" }
+            return
+          end
+
+          @mutex.synchronize do
+            @skipped_tests_count += 1
+          end
+        end
+
         def shutdown!
           @coverage_writer&.stop
         end
diff --git a/lib/datadog/ci/test.rb b/lib/datadog/ci/test.rb
index a72acddf..191528ce 100644
--- a/lib/datadog/ci/test.rb
+++ b/lib/datadog/ci/test.rb
@@ -62,6 +62,12 @@ def source_file
         get_tag(Ext::Test::TAG_SOURCE_FILE)
       end
 
+      # Returns "true" if the test is skipped by the ITR.
+      # @return [Boolean] true if the test is skipped by the ITR, false otherwise.
+      def skipped_by_itr?
+        get_tag(Ext::Test::TAG_ITR_SKIPPED_BY_ITR) == "true"
+      end
+
       # Sets the status of the span to "pass".
       # @return [void]
       def passed!
diff --git a/lib/datadog/ci/test_visibility/recorder.rb b/lib/datadog/ci/test_visibility/recorder.rb
index d3a07414..52b759f9 100644
--- a/lib/datadog/ci/test_visibility/recorder.rb
+++ b/lib/datadog/ci/test_visibility/recorder.rb
@@ -127,21 +127,18 @@ def trace_test(test_name, test_suite_name, service: nil, tags: {}, &block)
               test = build_test(tracer_span, tags)
 
               @local_context.activate_test(test) do
-                @itr.start_coverage
-
+                on_test_started(test)
                 res = block.call(test)
                 on_test_finished(test)
-
                 res
               end
             end
           else
             tracer_span = start_datadog_tracer_span(test_name, span_options)
-
             test = build_test(tracer_span, tags)
 
             @local_context.activate_test(test)
-            @itr.start_coverage
+            on_test_started(test)
 
             test
           end
@@ -402,6 +399,11 @@ def validate_test_suite_level_visibility_correctness(test)
         def on_test_finished(test)
           @itr.stop_coverage(test)
         end
+
+        def on_test_started(test)
+          @itr.mark_if_skippable(test)
+          @itr.start_coverage
+        end
       end
     end
   end
diff --git a/sig/datadog/ci/ext/test.rbs b/sig/datadog/ci/ext/test.rbs
index dc308af1..c5b954a3 100644
--- a/sig/datadog/ci/ext/test.rbs
+++ b/sig/datadog/ci/ext/test.rbs
@@ -36,6 +36,8 @@ module Datadog
 
         TAG_ITR_TEST_SKIPPING_TYPE: "test.itr.tests_skipping.type"
 
+        TAG_ITR_SKIPPED_BY_ITR: "test.itr.skipped_by_itr"
+
         TAG_CODE_COVERAGE_ENABLED: "test.code_coverage.enabled"
 
         TAG_TEST_SESSION_ID: "_test.session_id"
diff --git a/sig/datadog/ci/itr/runner.rbs b/sig/datadog/ci/itr/runner.rbs
index 180d7aca..4da4dd1e 100644
--- a/sig/datadog/ci/itr/runner.rbs
+++ b/sig/datadog/ci/itr/runner.rbs
@@ -2,16 +2,21 @@ module Datadog
   module CI
     module ITR
       class Runner
+        include Datadog::Core::Utils::Forking
+
         @enabled: bool
         @test_skipping_enabled: bool
         @code_coverage_enabled: bool
         @correlation_id: String
-        @skippable_tests: Array[Datadog::CI::ITR::Skippable::Test]
+        @skippable_tests: Array[String]
         @coverage_writer: Datadog::CI::ITR::Coverage::Writer?
 
         @api: Datadog::CI::Transport::Api::Base?
         @dd_env: String?
 
+        @skipped_tests_count: Integer
+        @mutex: Thread::Mutex
+
         def initialize: (dd_env: String?, ?enabled: bool, coverage_writer: Datadog::CI::ITR::Coverage::Writer?, api: Datadog::CI::Transport::Api::Base?) -> void
 
         def configure: (Hash[String, untyped] remote_configuration, test_session: Datadog::CI::TestSession, git_tree_upload_worker: Datadog::CI::Worker) -> void
@@ -26,6 +31,8 @@ module Datadog
 
         def stop_coverage: (Datadog::CI::Test test) -> Datadog::CI::ITR::Coverage::Event?
 
+        def mark_if_skippable: (Datadog::CI::Test test) -> void
+
         def shutdown!: () -> void
 
         private
@@ -39,6 +46,8 @@ module Datadog
         def ensure_test_source_covered: (String test_source_file, Hash[String, untyped] coverage) -> void
 
         def fetch_skippable_tests: (test_session: Datadog::CI::TestSession, git_tree_upload_worker: Datadog::CI::Worker) -> void
+
+        def increment_skipped_tests_counter: () -> void
       end
     end
   end
diff --git a/sig/datadog/ci/test.rbs b/sig/datadog/ci/test.rbs
index ab77f7d0..c79be5ff 100644
--- a/sig/datadog/ci/test.rbs
+++ b/sig/datadog/ci/test.rbs
@@ -7,6 +7,7 @@ module Datadog
       def test_suite_name: () -> String?
       def test_module_id: () -> String?
       def test_session_id: () -> String?
+      def skipped_by_itr?: () -> bool
       def source_file: () -> String?
 
       private
diff --git a/sig/datadog/ci/test_visibility/recorder.rbs b/sig/datadog/ci/test_visibility/recorder.rbs
index 0363922b..a753203c 100644
--- a/sig/datadog/ci/test_visibility/recorder.rbs
+++ b/sig/datadog/ci/test_visibility/recorder.rbs
@@ -93,6 +93,8 @@ module Datadog
         def validate_test_suite_level_visibility_correctness: (Datadog::CI::Test test) -> void
 
         def on_test_finished: (Datadog::CI::Test test) -> void
+
+        def on_test_started: (Datadog::CI::Test test) -> void
       end
     end
   end
diff --git a/sig/datadog/ci/utils/test_run.rbs b/sig/datadog/ci/utils/test_run.rbs
index 66fef457..887b5292 100644
--- a/sig/datadog/ci/utils/test_run.rbs
+++ b/sig/datadog/ci/utils/test_run.rbs
@@ -6,7 +6,7 @@ module Datadog
 
         def self.command: () -> String
 
-        def self.test_full_name: (String test_name, String test_suite) -> String
+        def self.test_full_name: (String test_name, String? test_suite) -> String
       end
     end
   end
diff --git a/spec/datadog/ci/itr/runner_spec.rb b/spec/datadog/ci/itr/runner_spec.rb
index 6fd53fd5..f9e6f028 100644
--- a/spec/datadog/ci/itr/runner_spec.rb
+++ b/spec/datadog/ci/itr/runner_spec.rb
@@ -201,4 +201,92 @@
       end
     end
   end
+
+  describe "#mark_if_skippable" do
+    subject { runner.mark_if_skippable(test_span) }
+
+    context "when skipping tests" do
+      let(:remote_configuration) { {"itr_enabled" => true, "code_coverage" => true, "tests_skipping" => true} }
+      let(:skippable) do
+        instance_double(
+          Datadog::CI::ITR::Skippable,
+          fetch_skippable_tests: instance_double(
+            Datadog::CI::ITR::Skippable::Response,
+            correlation_id: "42",
+            tests: Set.new(["suite.test"])
+          )
+        )
+      end
+
+      before do
+        expect(Datadog::CI::ITR::Skippable).to receive(:new).and_return(skippable)
+
+        configure
+      end
+
+      context "when test is skippable" do
+        let(:test_span) do
+          Datadog::CI::Test.new(
+            Datadog::Tracing::SpanOperation.new("test", tags: {"test.name" => "test", "test.suite" => "suite"})
+          )
+        end
+
+        it "marks test as skippable" do
+          expect { subject }
+            .to change { test_span.skipped_by_itr? }
+            .from(false)
+            .to(true)
+        end
+
+        it "increments skipped tests count" do
+          expect { subject }
+            .to change { runner.skipped_tests_count }
+            .from(0)
+            .to(1)
+        end
+      end
+
+      context "when test is not skippable" do
+        let(:test_span) do
+          Datadog::CI::Test.new(
+            Datadog::Tracing::SpanOperation.new("test", tags: {"test.name" => "test", "test.suite" => "test"})
+          )
+        end
+
+        it "does not mark test as skippable" do
+          expect { subject }
+            .not_to change { test_span.skipped_by_itr? }
+        end
+
+        it "does not increment skipped tests count" do
+          expect { subject }
+            .not_to change { runner.skipped_tests_count }
+        end
+      end
+    end
+
+    context "when not skipping tests" do
+      let(:remote_configuration) { {"itr_enabled" => true, "code_coverage" => true, "tests_skipping" => false} }
+
+      before do
+        configure
+      end
+
+      let(:test_span) do
+        Datadog::CI::Test.new(
+          Datadog::Tracing::SpanOperation.new("test", tags: {"test.name" => "test", "test.suite" => "suite"})
+        )
+      end
+
+      it "does not mark test as skippable" do
+        expect { subject }
+          .not_to change { test_span.skipped_by_itr? }
+      end
+
+      it "does not increment skipped tests count" do
+        expect { subject }
+          .not_to change { runner.skipped_tests_count }
+      end
+    end
+  end
 end
diff --git a/spec/datadog/ci/test_spec.rb b/spec/datadog/ci/test_spec.rb
index f474145f..5f8053ef 100644
--- a/spec/datadog/ci/test_spec.rb
+++ b/spec/datadog/ci/test_spec.rb
@@ -99,6 +99,26 @@
     it { is_expected.to eq("foo/bar.rb") }
   end
 
+  describe "#skipped_by_itr?" do
+    subject(:skipped_by_itr) { ci_test.skipped_by_itr? }
+
+    context "when tag is set" do
+      before do
+        allow(tracer_span).to(
+          receive(:get_tag).with(Datadog::CI::Ext::Test::TAG_ITR_SKIPPED_BY_ITR).and_return("true")
+        )
+      end
+
+      it { is_expected.to be true }
+    end
+
+    context "when tag is not set" do
+      before { allow(tracer_span).to receive(:get_tag).with(Datadog::CI::Ext::Test::TAG_ITR_SKIPPED_BY_ITR).and_return(nil) }
+
+      it { is_expected.to be false }
+    end
+  end
+
   describe "#set_parameters" do
     let(:parameters) { {"foo" => "bar", "baz" => "qux"} }