diff --git a/extensions/cornerstone-dicom-seg/src/getToolbarModule.ts b/extensions/cornerstone-dicom-seg/src/getToolbarModule.ts
index ab1dcd58b35..f2d7aec8291 100644
--- a/extensions/cornerstone-dicom-seg/src/getToolbarModule.ts
+++ b/extensions/cornerstone-dicom-seg/src/getToolbarModule.ts
@@ -17,6 +17,15 @@ export function getToolbarModule({ servicesManager }: withAppTypes) {
           };
         }
 
+        const activeSegmentation = segmentationService.getActiveSegmentation(viewportId);
+        if (!Object.keys(activeSegmentation.segments).length) {
+          return {
+            disabled: true,
+            className: '!text-common-bright !bg-black opacity-50',
+            disabledText: 'Add segment to enable this tool',
+          };
+        }
+
         const toolGroup = toolGroupService.getToolGroupForViewport(viewportId);
 
         if (!toolGroup) {
diff --git a/extensions/cornerstone/src/index.tsx b/extensions/cornerstone/src/index.tsx
index 41f4c33ff0d..d51c8ff51c6 100644
--- a/extensions/cornerstone/src/index.tsx
+++ b/extensions/cornerstone/src/index.tsx
@@ -96,6 +96,7 @@ const cornerstoneExtension: Types.Extensions.Extension = {
     toolbarService.registerEventForToolbarUpdate(segmentationService, [
       segmentationService.EVENTS.SEGMENTATION_REMOVED,
       segmentationService.EVENTS.SEGMENTATION_MODIFIED,
+      segmentationService.EVENTS.SEGMENTATION_CHANGED,
     ]);
 
     toolbarService.registerEventForToolbarUpdate(cornerstone.eventTarget, [
diff --git a/extensions/cornerstone/src/services/SegmentationService/SegmentationService.ts b/extensions/cornerstone/src/services/SegmentationService/SegmentationService.ts
index b2595585459..e30ad66cb3e 100644
--- a/extensions/cornerstone/src/services/SegmentationService/SegmentationService.ts
+++ b/extensions/cornerstone/src/services/SegmentationService/SegmentationService.ts
@@ -28,6 +28,7 @@ import { updateLabelmapSegmentationImageReferences } from '@cornerstonejs/tools/
 import { triggerSegmentationRepresentationModified } from '@cornerstonejs/tools/segmentation/triggerSegmentationEvents';
 import { convertStackToVolumeLabelmap } from '@cornerstonejs/tools/segmentation/helpers/convertStackToVolumeLabelmap';
 import { getLabelmapImageIds } from '@cornerstonejs/tools/segmentation';
+import setSegToolModeForToolGroups from '../../utils/setSegToolModeForToolGroups';
 
 const LABELMAP = csToolsEnums.SegmentationRepresentations.Labelmap;
 const CONTOUR = csToolsEnums.SegmentationRepresentations.Contour;
@@ -64,6 +65,8 @@ const EVENTS = {
   SEGMENTATION_DATA_MODIFIED: 'event::segmentation_data_modified',
   // fired when the segmentation is removed
   SEGMENTATION_REMOVED: 'event::segmentation_removed',
+  // fired when the segmentation is changed
+  SEGMENTATION_CHANGED: 'event::segmentation_changed',
   //
   // fired when segmentation representation is added
   SEGMENTATION_REPRESENTATION_MODIFIED: 'event::segmentation_representation_modified',
@@ -361,11 +364,11 @@ class SegmentationService extends PubSubService {
           options.segments && Object.keys(options.segments).length > 0
             ? options.segments
             : {
-              1: {
-                label: 'Segment 1',
-                active: true,
+                1: {
+                  label: 'Segment 1',
+                  active: true,
+                },
               },
-            },
         cachedStats: {
           info: `S${displaySet.SeriesNumber}: ${displaySet.SeriesDescription}`,
         },
@@ -382,8 +385,8 @@ class SegmentationService extends PubSubService {
       segmentationId?: string;
       type: SegmentationRepresentations;
     } = {
-        type: LABELMAP,
-      }
+      type: LABELMAP,
+    }
   ): Promise<string> {
     const { type } = options;
     let { segmentationId } = options;
@@ -535,8 +538,8 @@ class SegmentationService extends PubSubService {
       segmentationId?: string;
       type: SegmentationRepresentations;
     } = {
-        type: CONTOUR,
-      }
+      type: CONTOUR,
+    }
   ): Promise<string> {
     const { type } = options;
     let { segmentationId } = options;
@@ -687,10 +690,28 @@ class SegmentationService extends PubSubService {
       // Add a new segmentation
       this.addSegmentationToSource(data as cstTypes.SegmentationPublicInput);
     }
+    const { toolGroupService } = this.servicesManager.services;
+    setSegToolModeForToolGroups(toolGroupService, csToolsEnums.ToolModes.Active);
   }
 
   public setActiveSegmentation(viewportId: string, segmentationId: string): void {
+    const segmentation = this.getSegmentation(segmentationId);
+    const segments = segmentation.segments;
+    const { toolGroupService } = this.servicesManager.services;
+
+    // Set the tool mode based on the presence of segments
+    const toolMode = Object.keys(segments).length
+      ? csToolsEnums.ToolModes.Active
+      : csToolsEnums.ToolModes.Passive;
+
     cstSegmentation.activeSegmentation.setActiveSegmentation(viewportId, segmentationId);
+
+    // Set the tool mode for the tool group
+    setSegToolModeForToolGroups(toolGroupService, toolMode);
+
+    this._broadcastEvent(EVENTS.SEGMENTATION_CHANGED, {
+      segmentationId,
+    });
   }
 
   /**
@@ -808,7 +829,7 @@ class SegmentationService extends PubSubService {
     if (!segmentIndex) {
       // grab the next available segment index based on the object keys,
       // so basically get the highest segment index value + 1
-      segmentIndex = Math.max(...Object.keys(csSegmentation.segments).map(Number)) + 1;
+      segmentIndex = Math.max(0, ...Object.keys(csSegmentation.segments).map(Number)) + 1;
     }
 
     // update the segmentation
@@ -874,6 +895,15 @@ class SegmentationService extends PubSubService {
    */
   public removeSegment(segmentationId: string, segmentIndex: number): void {
     cstSegmentation.removeSegment(segmentationId, segmentIndex);
+    const segmentation = this.getSegmentation(segmentationId);
+    const segments = segmentation.segments;
+
+    // Set the tool to passive mode if there are no segments in the active segmentation.
+    if (!Object.keys(segments).length) {
+      const { toolGroupService } = this.servicesManager.services;
+
+      setSegToolModeForToolGroups(toolGroupService, csToolsEnums.ToolModes.Passive);
+    }
   }
 
   public setSegmentVisibility(
@@ -1704,7 +1734,17 @@ class SegmentationService extends PubSubService {
   };
 
   private _setActiveSegment(segmentationId: string, segmentIndex: number) {
+    const segmentation = this.getSegmentation(segmentationId);
+    const segments = segmentation.segments;
+
     cstSegmentation.segmentIndex.setActiveSegmentIndex(segmentationId, segmentIndex);
+
+    // Set the tool to active mode if there is at least one segment in the active segmentation.
+    if (Object.keys(segments).length) {
+      const { toolGroupService } = this.servicesManager.services;
+
+      setSegToolModeForToolGroups(toolGroupService, csToolsEnums.ToolModes.Active);
+    }
   }
 
   private _getVolumeIdForDisplaySet(displaySet) {
diff --git a/extensions/cornerstone/src/utils/SegmentationTools.ts b/extensions/cornerstone/src/utils/SegmentationTools.ts
new file mode 100644
index 00000000000..d9ceb195d53
--- /dev/null
+++ b/extensions/cornerstone/src/utils/SegmentationTools.ts
@@ -0,0 +1,14 @@
+const segmentationTools = [
+  'CircularBrush',
+  'SphereBrush',
+  'CircularEraser',
+  'SphereEraser',
+  'CircleScissor',
+  'RectangleScissor',
+  'SphereScissor',
+  'ThresholdCircularBrush',
+  'ThresholdSphereBrush',
+  'ThresholdCircularBrushDynamic',
+];
+
+export { segmentationTools };
diff --git a/extensions/cornerstone/src/utils/setSegToolModeForToolGroups.ts b/extensions/cornerstone/src/utils/setSegToolModeForToolGroups.ts
new file mode 100644
index 00000000000..b8c616ab476
--- /dev/null
+++ b/extensions/cornerstone/src/utils/setSegToolModeForToolGroups.ts
@@ -0,0 +1,33 @@
+import { Enums } from '@cornerstonejs/tools';
+import ToolGroupService from '../services/ToolGroupService';
+import { segmentationTools } from './SegmentationTools';
+
+/**
+ * Sets the mode for segmentation tools in all tool groups managed by the tool group service.
+ *
+ * @param toolGroupService - The service managing the tool groups.
+ * @param mode - The mode to set for the tools (e.g., Active, Enabled, Passive, Disabled).
+ */
+const setSegToolModeForToolGroups = (toolGroupService: ToolGroupService, mode: Enums.ToolModes) => {
+  const toolGroupIds = toolGroupService.getToolGroupIds();
+  toolGroupIds.forEach(toolGroupId => {
+    const toolGroup = toolGroupService.getToolGroup(toolGroupId);
+    if (!toolGroup) {
+      return;
+    }
+    const toolName = toolGroup.currentActivePrimaryToolName;
+    if (!toolName || !toolGroup.hasTool(toolName) || !segmentationTools.includes(toolName)) {
+      return;
+    }
+    let options;
+
+    if (mode === Enums.ToolModes.Active) {
+      options = {
+        bindings: [{ mouseButton: Enums.MouseBindings.Primary }],
+      };
+    }
+    toolGroup.setToolMode(toolName, mode, options);
+  });
+};
+
+export default setSegToolModeForToolGroups;