diff --git a/codex-rs/core/src/config/edit.rs b/codex-rs/core/src/config/edit.rs
index 3940adf40b..a24c09e36b 100644
--- a/codex-rs/core/src/config/edit.rs
+++ b/codex-rs/core/src/config/edit.rs
@@ -631,36 +631,6 @@ impl ConfigEditsBuilder {
         self
     }
 
-    pub fn set_pending_model_migration_notice(mut self, from_model: &str, to_model: &str) -> Self {
-        self.edits.push(ConfigEdit::SetPath {
-            segments: vec![
-                Notice::TABLE_KEY.to_string(),
-                "pending_model_migration".to_string(),
-                "from_model".to_string(),
-            ],
-            value: value(from_model.to_string()),
-        });
-        self.edits.push(ConfigEdit::SetPath {
-            segments: vec![
-                Notice::TABLE_KEY.to_string(),
-                "pending_model_migration".to_string(),
-                "to_model".to_string(),
-            ],
-            value: value(to_model.to_string()),
-        });
-        self
-    }
-
-    pub fn clear_pending_model_migration_notice(mut self) -> Self {
-        self.edits.push(ConfigEdit::ClearPath {
-            segments: vec![
-                Notice::TABLE_KEY.to_string(),
-                "pending_model_migration".to_string(),
-            ],
-        });
-        self
-    }
-
     pub fn set_windows_wsl_setup_acknowledged(mut self, acknowledged: bool) -> Self {
         self.edits
             .push(ConfigEdit::SetWindowsWslSetupAcknowledged(acknowledged));
diff --git a/codex-rs/core/src/config/types.rs b/codex-rs/core/src/config/types.rs
index 4dcf96c7a2..3aa72d5ce5 100644
--- a/codex-rs/core/src/config/types.rs
+++ b/codex-rs/core/src/config/types.rs
@@ -514,12 +514,6 @@ const fn default_true() -> bool {
 /// Settings for notices we display to users via the tui and app-server clients
 /// (primarily the Codex IDE extension). NOTE: these are different from
 /// notifications - notices are warnings, NUX screens, acknowledgements, etc.
-#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq)]
-pub struct PendingModelMigrationNotice {
-    pub from_model: String,
-    pub to_model: String,
-}
-
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
 pub struct Notice {
     /// Tracks whether the user has acknowledged the full access warning prompt.
@@ -536,8 +530,6 @@ pub struct Notice {
     /// Tracks acknowledged model migrations as old->new model slug mappings.
     #[serde(default)]
     pub model_migrations: BTreeMap<String, String>,
-    /// Persisted "show on next run" model migration notice.
-    pub pending_model_migration: Option<PendingModelMigrationNotice>,
 }
 
 impl Notice {
diff --git a/codex-rs/tui/src/app.rs b/codex-rs/tui/src/app.rs
index 4270fd30e2..d7be885ebd 100644
--- a/codex-rs/tui/src/app.rs
+++ b/codex-rs/tui/src/app.rs
@@ -217,9 +217,20 @@ impl App {
     }
 
     async fn maybe_emit_pending_model_migration_notice(&mut self, used_model: &str) {
-        let Some(pending) = self.config.notices.pending_model_migration.take() else {
-            return;
-        };
+        let pending =
+            match crate::model_migration_notice::read_pending_model_migration_notice(&self.config)
+                .await
+            {
+                Ok(Some(pending)) => pending,
+                Ok(None) => return,
+                Err(err) => {
+                    tracing::error!(
+                        error = %err,
+                        "failed to read pending model migration notice"
+                    );
+                    return;
+                }
+            };
 
         let should_show = pending.from_model == used_model;
         if should_show {
@@ -237,20 +248,31 @@ impl App {
                 .insert(pending.from_model.clone(), pending.to_model.clone());
         }
 
-        let mut edits = ConfigEditsBuilder::new(&self.config.codex_home);
         if should_show {
-            edits = edits.record_model_migration_seen(
-                pending.from_model.as_str(),
-                pending.to_model.as_str(),
-            );
+            if let Err(err) = ConfigEditsBuilder::new(&self.config.codex_home)
+                .record_model_migration_seen(pending.from_model.as_str(), pending.to_model.as_str())
+                .apply()
+                .await
+            {
+                tracing::error!(
+                    error = %err,
+                    "failed to persist model migration notice acknowledgement"
+                );
+                self.chat_widget.add_error_message(format!(
+                    "Failed to persist model migration notice acknowledgement: {err}"
+                ));
+            }
         }
-        if let Err(err) = edits.clear_pending_model_migration_notice().apply().await {
+
+        if let Err(err) =
+            crate::model_migration_notice::clear_pending_model_migration_notice(&self.config).await
+        {
             tracing::error!(
                 error = %err,
-                "failed to clear pending model migration notice"
+                "failed to clear pending model migration notice file"
             );
             self.chat_widget.add_error_message(format!(
-                "Failed to persist model migration notice state: {err}"
+                "Failed to clear pending model migration notice: {err}"
             ));
         }
     }
@@ -285,10 +307,12 @@ impl App {
                 return;
             }
 
-            if let Err(err) = ConfigEditsBuilder::new(&config.codex_home)
-                .set_pending_model_migration_notice(used_model.as_str(), target_model.as_str())
-                .apply()
-                .await
+            if let Err(err) = crate::model_migration_notice::write_pending_model_migration_notice(
+                &config,
+                used_model.as_str(),
+                target_model.as_str(),
+            )
+            .await
             {
                 tracing::error!(
                     error = %err,
diff --git a/codex-rs/tui/src/lib.rs b/codex-rs/tui/src/lib.rs
index ba10c147e4..42f3f4a07b 100644
--- a/codex-rs/tui/src/lib.rs
+++ b/codex-rs/tui/src/lib.rs
@@ -57,6 +57,7 @@ pub mod live_wrap;
 mod markdown;
 mod markdown_render;
 mod markdown_stream;
+pub mod model_migration_notice;
 // Model migration prompt UI is no longer used in production; keep it for snapshot tests.
 #[cfg(test)]
 mod model_migration;
diff --git a/codex-rs/tui2/src/app.rs b/codex-rs/tui2/src/app.rs
index 69aef667f1..7f4fe4ea89 100644
--- a/codex-rs/tui2/src/app.rs
+++ b/codex-rs/tui2/src/app.rs
@@ -283,8 +283,20 @@ impl App {
     }
 
     async fn maybe_emit_pending_model_migration_notice(&mut self, used_model: &str) {
-        let Some(pending) = self.config.notices.pending_model_migration.take() else {
-            return;
+        let pending = match codex_tui::model_migration_notice::read_pending_model_migration_notice(
+            &self.config,
+        )
+        .await
+        {
+            Ok(Some(pending)) => pending,
+            Ok(None) => return,
+            Err(err) => {
+                tracing::error!(
+                    error = %err,
+                    "failed to read pending model migration notice"
+                );
+                return;
+            }
         };
 
         let should_show = pending.from_model == used_model;
@@ -303,20 +315,32 @@ impl App {
                 .insert(pending.from_model.clone(), pending.to_model.clone());
         }
 
-        let mut edits = ConfigEditsBuilder::new(&self.config.codex_home);
         if should_show {
-            edits = edits.record_model_migration_seen(
-                pending.from_model.as_str(),
-                pending.to_model.as_str(),
-            );
+            if let Err(err) = ConfigEditsBuilder::new(&self.config.codex_home)
+                .record_model_migration_seen(pending.from_model.as_str(), pending.to_model.as_str())
+                .apply()
+                .await
+            {
+                tracing::error!(
+                    error = %err,
+                    "failed to persist model migration notice acknowledgement"
+                );
+                self.chat_widget.add_error_message(format!(
+                    "Failed to persist model migration notice acknowledgement: {err}"
+                ));
+            }
         }
-        if let Err(err) = edits.clear_pending_model_migration_notice().apply().await {
+
+        if let Err(err) =
+            codex_tui::model_migration_notice::clear_pending_model_migration_notice(&self.config)
+                .await
+        {
             tracing::error!(
                 error = %err,
-                "failed to clear pending model migration notice"
+                "failed to clear pending model migration notice file"
             );
             self.chat_widget.add_error_message(format!(
-                "Failed to persist model migration notice state: {err}"
+                "Failed to clear pending model migration notice: {err}"
             ));
         }
     }
@@ -351,9 +375,12 @@ impl App {
                 return;
             }
 
-            if let Err(err) = ConfigEditsBuilder::new(&config.codex_home)
-                .set_pending_model_migration_notice(used_model.as_str(), target_model.as_str())
-                .apply()
+            if let Err(err) =
+                codex_tui::model_migration_notice::write_pending_model_migration_notice(
+                    &config,
+                    used_model.as_str(),
+                    target_model.as_str(),
+                )
                 .await
             {
                 tracing::error!(