diff --git a/app/src/androidTest/java/com/m57/hermescontrol/ui/model/ModelScreenTest.kt b/app/src/androidTest/java/com/m57/hermescontrol/ui/model/ModelScreenTest.kt
index c2b9a66e..1ddf87c3 100644
--- a/app/src/androidTest/java/com/m57/hermescontrol/ui/model/ModelScreenTest.kt
+++ b/app/src/androidTest/java/com/m57/hermescontrol/ui/model/ModelScreenTest.kt
@@ -2,7 +2,9 @@ package com.m57.hermescontrol.ui.model
 
 import androidx.compose.ui.test.assertIsDisplayed
 import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onNodeWithContentDescription
 import androidx.compose.ui.test.onNodeWithText
+import androidx.compose.ui.test.performClick
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.filters.MediumTest
 import com.m57.hermescontrol.data.model.ModelProvider
@@ -62,6 +64,34 @@ class ModelScreenTest {
         composeTestRule.onNodeWithText("Pinned Models").assertDoesNotExist()
     }
 
+    @Test
+    fun modelScreen_providerExpansionArrowMatchesState() {
+        uiStateFlow.value =
+            ModelUiState(
+                providers =
+                    listOf(
+                        ModelProvider(
+                            slug = "openai",
+                            name = "OpenAI",
+                            models = listOf("gpt-4"),
+                        ),
+                    ),
+            )
+
+        composeTestRule.setContent {
+            ModelScreen(
+                onOpenDrawer = {},
+                viewModel = mockViewModel,
+            )
+        }
+
+        composeTestRule.onNodeWithText("gpt-4").assertDoesNotExist()
+        composeTestRule.onNodeWithContentDescription("Expand OpenAI models").performClick()
+        composeTestRule.onNodeWithText("gpt-4").assertIsDisplayed()
+        composeTestRule.onNodeWithContentDescription("Collapse OpenAI models").performClick()
+        composeTestRule.onNodeWithText("gpt-4").assertDoesNotExist()
+    }
+
     @Test
     fun modelScreen_rendersPinnedModels_whenPresent() {
         uiStateFlow.value =
diff --git a/app/src/androidTest/java/com/m57/hermescontrol/ui/model/components/ModelPickerDialogTest.kt b/app/src/androidTest/java/com/m57/hermescontrol/ui/model/components/ModelPickerDialogTest.kt
new file mode 100644
index 00000000..cfffcad7
--- /dev/null
+++ b/app/src/androidTest/java/com/m57/hermescontrol/ui/model/components/ModelPickerDialogTest.kt
@@ -0,0 +1,151 @@
+package com.m57.hermescontrol.ui.model.components
+
+import androidx.compose.ui.test.assertCountEquals
+import androidx.compose.ui.test.assertIsDisplayed
+import androidx.compose.ui.test.hasSetTextAction
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onAllNodesWithText
+import androidx.compose.ui.test.onNodeWithContentDescription
+import androidx.compose.ui.test.onNodeWithText
+import androidx.compose.ui.test.performClick
+import androidx.compose.ui.test.performTextInput
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.MediumTest
+import com.m57.hermescontrol.data.model.ModelCapabilities
+import com.m57.hermescontrol.data.model.ModelProvider
+import com.m57.hermescontrol.data.model.PinnedModel
+import com.m57.hermescontrol.theme.HermesControlTheme
+import org.junit.Assert.assertEquals
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+@MediumTest
+class ModelPickerDialogTest {
+    @get:Rule
+    val composeTestRule = createComposeRule()
+
+    @Test
+    fun providers_startCollapsed_andOnlyOneProviderExpands() {
+        composeTestRule.setContent {
+            HermesControlTheme {
+                ModelPickerDialog(
+                    providers =
+                        listOf(
+                            ModelProvider(slug = "openai", name = "OpenAI", models = listOf("gpt-4")),
+                            ModelProvider(slug = "anthropic", name = "Anthropic", models = listOf("claude-3")),
+                        ),
+                    title = "Choose model",
+                    onSelect = { _, _ -> },
+                    onDismiss = {},
+                )
+            }
+        }
+
+        composeTestRule.onNodeWithText("gpt-4").assertDoesNotExist()
+        composeTestRule.onNodeWithText("claude-3").assertDoesNotExist()
+        composeTestRule.onAllNodesWithText("1 model").assertCountEquals(2)
+        composeTestRule.onNodeWithContentDescription("Expand OpenAI models").assertIsDisplayed()
+        composeTestRule.onNodeWithContentDescription("Expand Anthropic models").assertIsDisplayed()
+
+        composeTestRule.onNodeWithContentDescription("Expand OpenAI models").performClick()
+        composeTestRule.onNodeWithText("gpt-4").assertIsDisplayed()
+        composeTestRule.onNodeWithContentDescription("Collapse OpenAI models").assertIsDisplayed()
+        composeTestRule.onNodeWithText("claude-3").assertDoesNotExist()
+
+        composeTestRule.onNodeWithContentDescription("Expand Anthropic models").performClick()
+        composeTestRule.onNodeWithText("gpt-4").assertDoesNotExist()
+        composeTestRule.onNodeWithText("claude-3").assertIsDisplayed()
+        composeTestRule.onNodeWithContentDescription("Collapse Anthropic models").assertIsDisplayed()
+
+        composeTestRule.onNodeWithContentDescription("Collapse Anthropic models").performClick()
+        composeTestRule.onNodeWithText("claude-3").assertDoesNotExist()
+        composeTestRule.onNodeWithContentDescription("Expand Anthropic models").assertIsDisplayed()
+    }
+
+    @Test
+    fun search_filtersModelsAndCountsMatches_beforeSelection() {
+        var selectedProvider = ""
+        var selectedModel = ""
+
+        composeTestRule.setContent {
+            HermesControlTheme {
+                ModelPickerDialog(
+                    providers =
+                        listOf(
+                            ModelProvider(
+                                slug = "openai",
+                                name = "OpenAI",
+                                models = listOf("gpt-4", "embedding-3"),
+                            ),
+                            ModelProvider(slug = "anthropic", name = "Anthropic", models = listOf("claude-3")),
+                        ),
+                    title = "Choose model",
+                    onSelect = { provider, model ->
+                        selectedProvider = provider
+                        selectedModel = model
+                    },
+                    onDismiss = {},
+                )
+            }
+        }
+
+        composeTestRule.onNodeWithText("2 models").assertIsDisplayed()
+        composeTestRule.onNode(hasSetTextAction()).performTextInput("gpt-4")
+        composeTestRule.onNodeWithText("1 model").assertIsDisplayed()
+        composeTestRule.onNodeWithText("embedding-3").assertDoesNotExist()
+        composeTestRule.onAllNodesWithText("gpt-4").assertCountEquals(1)
+
+        composeTestRule.onNodeWithContentDescription("Expand OpenAI models").performClick()
+        composeTestRule.onAllNodesWithText("gpt-4").get(1).performClick()
+
+        assertEquals("openai", selectedProvider)
+        assertEquals("gpt-4", selectedModel)
+    }
+
+    @Test
+    fun pinnedModels_remainVisibleAndPreserveCapabilitiesAndCallbacks() {
+        var toggledProvider = ""
+        var toggledModel = ""
+        var selectedProvider = ""
+        var selectedModel = ""
+
+        composeTestRule.setContent {
+            HermesControlTheme {
+                ModelPickerDialog(
+                    providers =
+                        listOf(
+                            ModelProvider(
+                                slug = "openai",
+                                name = "OpenAI",
+                                models = listOf("gpt-4"),
+                                capabilities = mapOf("gpt-4" to ModelCapabilities(reasoning = false)),
+                            ),
+                        ),
+                    title = "Choose model",
+                    pinnedModels = listOf(PinnedModel(providerSlug = "openai", modelName = "gpt-4")),
+                    onPinToggle = { provider, model ->
+                        toggledProvider = provider
+                        toggledModel = model
+                    },
+                    onSelect = { provider, model ->
+                        selectedProvider = provider
+                        selectedModel = model
+                    },
+                    onDismiss = {},
+                )
+            }
+        }
+
+        composeTestRule.onNodeWithText("gpt-4").assertIsDisplayed()
+        composeTestRule.onNodeWithText("no reasoning").assertIsDisplayed()
+        composeTestRule.onNodeWithContentDescription("Unpin model").performClick()
+        composeTestRule.onNodeWithText("gpt-4").performClick()
+
+        assertEquals("openai", toggledProvider)
+        assertEquals("gpt-4", toggledModel)
+        assertEquals("openai", selectedProvider)
+        assertEquals("gpt-4", selectedModel)
+    }
+}
diff --git a/app/src/main/java/com/m57/hermescontrol/ui/model/ModelScreen.kt b/app/src/main/java/com/m57/hermescontrol/ui/model/ModelScreen.kt
index a8baf000..b9790328 100644
--- a/app/src/main/java/com/m57/hermescontrol/ui/model/ModelScreen.kt
+++ b/app/src/main/java/com/m57/hermescontrol/ui/model/ModelScreen.kt
@@ -720,7 +720,7 @@ private fun ProviderCard(
                 horizontalArrangement = Arrangement.SpaceBetween,
                 verticalAlignment = Alignment.CenterVertically,
             ) {
-                Column {
+                Column(modifier = Modifier.weight(1f)) {
                     Text(
                         text = provider.name,
                         style = MaterialTheme.typography.titleMedium,
@@ -733,12 +733,36 @@ private fun ProviderCard(
                     )
                 }
 
-                if (isCurrent) {
-                    Text(
-                        text = stringResource(R.string.model_status_current),
-                        style = MaterialTheme.typography.labelMedium,
-                        color = MaterialTheme.colorScheme.primary,
-                        fontWeight = FontWeight.Bold,
+                Row(
+                    verticalAlignment = Alignment.CenterVertically,
+                    horizontalArrangement = Arrangement.spacedBy(4.dp),
+                ) {
+                    if (isCurrent) {
+                        Text(
+                            text = stringResource(R.string.model_status_current),
+                            style = MaterialTheme.typography.labelMedium,
+                            color = MaterialTheme.colorScheme.primary,
+                            fontWeight = FontWeight.Bold,
+                        )
+                    }
+                    Icon(
+                        imageVector =
+                            if (isExpanded) {
+                                Icons.Filled.KeyboardArrowUp
+                            } else {
+                                Icons.Filled.KeyboardArrowDown
+                            },
+                        contentDescription =
+                            stringResource(
+                                if (isExpanded) {
+                                    R.string.content_desc_collapse_provider
+                                } else {
+                                    R.string.content_desc_expand_provider
+                                },
+                                provider.name,
+                            ),
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                        modifier = Modifier.size(24.dp),
                     )
                 }
             }
diff --git a/app/src/main/java/com/m57/hermescontrol/ui/model/components/ModelPickerDialog.kt b/app/src/main/java/com/m57/hermescontrol/ui/model/components/ModelPickerDialog.kt
index 942f056a..0b576cb1 100644
--- a/app/src/main/java/com/m57/hermescontrol/ui/model/components/ModelPickerDialog.kt
+++ b/app/src/main/java/com/m57/hermescontrol/ui/model/components/ModelPickerDialog.kt
@@ -16,6 +16,8 @@ import androidx.compose.foundation.lazy.items
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Close
+import androidx.compose.material.icons.filled.KeyboardArrowDown
+import androidx.compose.material.icons.filled.KeyboardArrowUp
 import androidx.compose.material.icons.filled.PushPin
 import androidx.compose.material.icons.outlined.PushPin
 import androidx.compose.material3.AlertDialog
@@ -25,6 +27,7 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -32,6 +35,7 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.res.pluralStringResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
@@ -65,6 +69,7 @@ fun ModelPickerDialog(
     onDismiss: () -> Unit,
 ) {
     var pickerQuery by remember { mutableStateOf("") }
+    var expandedProviderSlug by remember { mutableStateOf<String?>(null) }
 
     AlertDialog(
         onDismissRequest = onDismiss,
@@ -149,6 +154,17 @@ fun ModelPickerDialog(
                             }
                         }
 
+                    LaunchedEffect(filteredProvidersWithModels) {
+                        if (
+                            expandedProviderSlug != null &&
+                            filteredProvidersWithModels.none { (provider, _) ->
+                                provider.slug == expandedProviderSlug
+                            }
+                        ) {
+                            expandedProviderSlug = null
+                        }
+                    }
+
                     SearchBar(
                         query = pickerQuery,
                         onQueryChange = { pickerQuery = it },
@@ -205,45 +221,83 @@ fun ModelPickerDialog(
 
                         // ── All providers / models (lazy item per model) ──
                         filteredProvidersWithModels.forEach { (provider, models) ->
+                            val isExpanded = expandedProviderSlug == provider.slug
                             item(key = "header:${provider.slug}") {
                                 Row(
+                                    modifier =
+                                        Modifier
+                                            .fillMaxWidth()
+                                            .clickable {
+                                                expandedProviderSlug =
+                                                    if (isExpanded) {
+                                                        null
+                                                    } else {
+                                                        provider.slug
+                                                    }
+                                            }.padding(top = 12.dp, bottom = 6.dp),
                                     verticalAlignment = Alignment.CenterVertically,
-                                    modifier = Modifier.padding(top = 12.dp, bottom = 6.dp),
+                                    horizontalArrangement = Arrangement.spacedBy(8.dp),
                                 ) {
                                     Text(
                                         text = provider.name,
                                         style = MaterialTheme.typography.labelLarge,
                                         fontWeight = FontWeight.Bold,
                                         color = MaterialTheme.colorScheme.onSurface,
+                                        modifier = Modifier.weight(1f),
                                     )
-                                    Spacer(modifier = Modifier.weight(1f))
                                     Text(
-                                        text = "${models.size} models",
+                                        text =
+                                            pluralStringResource(
+                                                R.plurals.model_provider_count,
+                                                models.size,
+                                                models.size,
+                                            ),
                                         style = MaterialTheme.typography.labelSmall,
                                         color = MaterialTheme.colorScheme.onSurfaceVariant,
                                     )
+                                    Icon(
+                                        imageVector =
+                                            if (isExpanded) {
+                                                Icons.Filled.KeyboardArrowUp
+                                            } else {
+                                                Icons.Filled.KeyboardArrowDown
+                                            },
+                                        contentDescription =
+                                            stringResource(
+                                                if (isExpanded) {
+                                                    R.string.content_desc_collapse_provider
+                                                } else {
+                                                    R.string.content_desc_expand_provider
+                                                },
+                                                provider.name,
+                                            ),
+                                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                                        modifier = Modifier.size(24.dp),
+                                    )
                                 }
                             }
 
-                            items(
-                                items = models,
-                                key = { model -> "${provider.slug}:$model" },
-                            ) { model ->
-                                val isPinned = "${provider.slug}:$model" in pinnedSet
-                                val caps = provider.capabilities?.get(model)
-                                ModelItemCard(
-                                    modelName = model,
-                                    isPinned = isPinned,
-                                    onPinToggle =
-                                        if (onPinToggle != null) {
-                                            { onPinToggle(provider.slug, model) }
-                                        } else {
-                                            null
-                                        },
-                                    onClick = { onSelect(provider.slug, model) },
-                                    canDisableReasoning = caps?.can_disable_reasoning,
-                                    supportsReasoning = caps?.reasoning,
-                                )
+                            if (isExpanded) {
+                                items(
+                                    items = models,
+                                    key = { model -> "${provider.slug}:$model" },
+                                ) { model ->
+                                    val isPinned = "${provider.slug}:$model" in pinnedSet
+                                    val caps = provider.capabilities?.get(model)
+                                    ModelItemCard(
+                                        modelName = model,
+                                        isPinned = isPinned,
+                                        onPinToggle =
+                                            if (onPinToggle != null) {
+                                                { onPinToggle(provider.slug, model) }
+                                            } else {
+                                                null
+                                            },
+                                        onClick = { onSelect(provider.slug, model) },
+                                        canDisableReasoning = caps?.can_disable_reasoning,
+                                        supportsReasoning = caps?.reasoning,
+                                    )
+                                }
                             }
                         }
                     }
diff --git a/app/src/main/res/values-ar/strings.xml b/app/src/main/res/values-ar/strings.xml
index dc295d82..3b45c33a 100644
--- a/app/src/main/res/values-ar/strings.xml
+++ b/app/src/main/res/values-ar/strings.xml
@@ -503,9 +503,19 @@
 <string name="model_label_available">النماذج المتاحة:</string>
 <string name="model_no_models">لم يتم العثور على نماذج أو أن المزود يحتاج إلى مصادقة.</string>
 <string name="content_desc_active_model">النموذج النشط</string>
+<string name="content_desc_expand_provider">توسيع نماذج %1$s</string>
+<string name="content_desc_collapse_provider">طي نماذج %1$s</string>
 <string name="model_section_pinned">النماذج المثبتة</string>
 <string name="content_desc_unpin_model">إلغاء تثبيت النموذج</string>
 <string name="content_desc_pinned_section_toggle">تبديل ظهور قسم المثبتات</string>
+<plurals name="model_provider_count">
+    <item quantity="zero">لا توجد نماذج</item>
+    <item quantity="one">%1$d نموذج</item>
+    <item quantity="two">%1$d نموذجان</item>
+    <item quantity="few">%1$d نماذج</item>
+    <item quantity="many">%1$d نموذجًا</item>
+    <item quantity="other">%1$d نموذج</item>
+</plurals>
 <string name="history_empty_title">لا يوجد سجل</string>
 <string name="history_empty_desc">ستظهر جلسات المحادثة السابقة من Hermes هنا.</string>
 <string name="history_untitled">بلا عنوان</string>
diff --git a/app/src/main/res/values-ko/strings.xml b/app/src/main/res/values-ko/strings.xml
index 40b7a9ba..2de852ca 100644
--- a/app/src/main/res/values-ko/strings.xml
+++ b/app/src/main/res/values-ko/strings.xml
@@ -393,10 +393,16 @@
     <string name="model_label_available">사용 가능한 모델:</string>
     <string name="model_no_models">보고된 모델이 없거나 인증이 필요합니다.</string>
     <string name="content_desc_active_model">활성 모델</string>
+    <string name="content_desc_expand_provider">%1$s 모델 펼치기</string>
+    <string name="content_desc_collapse_provider">%1$s 모델 접기</string>
     <string name="model_section_pinned">고정된 모델</string>
     <string name="model_confirm_continue">계속</string>
     <string name="content_desc_unpin_model">모델 고정 해제</string>
     <string name="content_desc_pinned_section_toggle">고정 섹션 표시 전환</string>
+    <plurals name="model_provider_count">
+        <item quantity="one">%1$d개 모델</item>
+        <item quantity="other">%1$d개 모델</item>
+    </plurals>
 
     <!-- Sessions (History) Screen -->
     <string name="history_empty_title">히스토리 없음</string>
diff --git a/app/src/main/res/values-zh/strings.xml b/app/src/main/res/values-zh/strings.xml
index 9cc43ed8..fa1c1d3c 100644
--- a/app/src/main/res/values-zh/strings.xml
+++ b/app/src/main/res/values-zh/strings.xml
@@ -494,9 +494,15 @@
     <string name="model_label_available">可用模型：</string>
     <string name="model_no_models">没有可用的模型，或提供商需要认证。</string>
     <string name="content_desc_active_model">当前模型</string>
+    <string name="content_desc_expand_provider">展开 %1$s 模型</string>
+    <string name="content_desc_collapse_provider">折叠 %1$s 模型</string>
     <string name="model_section_pinned">固定模型</string>
     <string name="content_desc_unpin_model">取消固定模型</string>
     <string name="content_desc_pinned_section_toggle">切换固定区显示</string>
+    <plurals name="model_provider_count">
+        <item quantity="one">%1$d 个模型</item>
+        <item quantity="other">%1$d 个模型</item>
+    </plurals>
     <string name="history_empty_title">暂无历史</string>
     <string name="history_empty_desc">之前的 Hermes 对话会话将显示在这里。</string>
     <string name="history_untitled">未命名</string>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 338bf909..a1b0d0ca 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -586,9 +586,15 @@
     <string name="model_label_available">Available Models:</string>
     <string name="model_no_models">No models reported or provider needs authentication.</string>
     <string name="content_desc_active_model">Active Model</string>
+    <string name="content_desc_expand_provider">Expand %1$s models</string>
+    <string name="content_desc_collapse_provider">Collapse %1$s models</string>
     <string name="model_section_pinned">Pinned Models</string>
     <string name="content_desc_unpin_model">Unpin model</string>
     <string name="content_desc_pinned_section_toggle">Toggle pinned section visibility</string>
+    <plurals name="model_provider_count">
+        <item quantity="one">%1$d model</item>
+        <item quantity="other">%1$d models</item>
+    </plurals>
 
     <!-- Sessions (History) Screen -->
     <string name="history_empty_title">No history</string>