diff --git a/contributing/samples/a2a_basic/agent.py b/contributing/samples/a2a_basic/agent.py
index 275511f4..294a9c0d 100755
--- a/contributing/samples/a2a_basic/agent.py
+++ b/contributing/samples/a2a_basic/agent.py
@@ -93,7 +93,7 @@ prime_agent = RemoteA2aAgent(
 
 
 root_agent = Agent(
-    model="gemini-1.5-flash",
+    model="gemini-2.0-flash",
     name="root_agent",
     instruction="""
       You are a helpful assistant that can roll dice and check if numbers are prime.
diff --git a/contributing/samples/a2a_human_in_loop/agent.py b/contributing/samples/a2a_human_in_loop/agent.py
index d15b5bb3..3b1313f2 100644
--- a/contributing/samples/a2a_human_in_loop/agent.py
+++ b/contributing/samples/a2a_human_in_loop/agent.py
@@ -33,7 +33,7 @@ approval_agent = RemoteA2aAgent(
 
 
 root_agent = Agent(
-    model='gemini-1.5-flash',
+    model='gemini-2.0-flash',
     name='reimbursement_agent',
     instruction="""
       You are an agent whose job is to handle the reimbursement process for
diff --git a/contributing/samples/a2a_human_in_loop/remote_a2a/human_in_loop/agent.py b/contributing/samples/a2a_human_in_loop/remote_a2a/human_in_loop/agent.py
index acf7e456..913fa44c 100644
--- a/contributing/samples/a2a_human_in_loop/remote_a2a/human_in_loop/agent.py
+++ b/contributing/samples/a2a_human_in_loop/remote_a2a/human_in_loop/agent.py
@@ -39,7 +39,7 @@ def ask_for_approval(
 
 
 root_agent = Agent(
-    model='gemini-1.5-flash',
+    model='gemini-2.0-flash',
     name='reimbursement_agent',
     instruction="""
       You are an agent whose job is to handle the reimbursement process for