diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/BindableDerivedListGeneratorTests.FromReactiveProperties#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/BindableDerivedListGeneratorTests.FromReactiveProperties#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..f529f0c 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/BindableDerivedListGeneratorTests.FromReactiveProperties#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/BindableDerivedListGeneratorTests.FromReactiveProperties#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.AccessModifiers#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.AccessModifiers#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
new file mode 100644
index 0000000..07ca7a2
--- /dev/null
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.AccessModifiers#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -0,0 +1,28 @@
+//HintName: ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.cs
+// Copyright (c) 2026 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+// <auto-generated/>
+#pragma warning disable
+#nullable enable
+namespace ReactiveUI.SourceGenerators;
+
+/// <summary>
+/// ReactiveAttribute.
+/// </summary>
+/// <seealso cref="Attribute" />
+[global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
+#nullable restore
+#pragma warning restore
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.AccessModifiers#TestNs.TestVM.BindableDerivedList.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.AccessModifiers#TestNs.TestVM.BindableDerivedList.g.verified.cs
new file mode 100644
index 0000000..51b6f37
--- /dev/null
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.AccessModifiers#TestNs.TestVM.BindableDerivedList.g.verified.cs
@@ -0,0 +1,36 @@
+//HintName: TestNs.TestVM.BindableDerivedList.g.cs
+// <auto-generated/>
+using System.Collections.ObjectModel;
+using DynamicData;
+using ReactiveUI;
+
+#pragma warning disable
+#nullable enable
+
+namespace TestNs
+{
+    
+    public partial class TestVM
+    {
+        /// <inheritdoc cref="_publicItems"/>
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        public global::System.Collections.ObjectModel.ReadOnlyObservableCollection<string>? PublicItems => _publicItems;
+        /// <inheritdoc cref="_protectedItems"/>
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        protected global::System.Collections.ObjectModel.ReadOnlyObservableCollection<string>? ProtectedItems => _protectedItems;
+        /// <inheritdoc cref="_internalItems"/>
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        internal global::System.Collections.ObjectModel.ReadOnlyObservableCollection<string>? InternalItems => _internalItems;
+        /// <inheritdoc cref="_privateItems"/>
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        private global::System.Collections.ObjectModel.ReadOnlyObservableCollection<string>? PrivateItems => _privateItems;
+        /// <inheritdoc cref="_internalProtectedItems"/>
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        protected internal global::System.Collections.ObjectModel.ReadOnlyObservableCollection<string>? InternalProtectedItems => _internalProtectedItems;
+        /// <inheritdoc cref="_privateProtectedItems"/>
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        private protected global::System.Collections.ObjectModel.ReadOnlyObservableCollection<string>? PrivateProtectedItems => _privateProtectedItems;
+    }
+}
+#nullable restore
+#pragma warning restore
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.ComplexGeneric#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.ComplexGeneric#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..f529f0c 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.ComplexGeneric#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.ComplexGeneric#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.DateTimeType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.DateTimeType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..f529f0c 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.DateTimeType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.DateTimeType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.DiffNamespaces#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.DiffNamespaces#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..07ca7a2 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.DiffNamespaces#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.DiffNamespaces#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
-#pragma warning restore
\ No newline at end of file
+#pragma warning restore
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.EnumType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.EnumType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..f529f0c 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.EnumType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.EnumType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.GenericClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.GenericClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..07ca7a2 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.GenericClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.GenericClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
-#pragma warning restore
\ No newline at end of file
+#pragma warning restore
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.GuidType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.GuidType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..f529f0c 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.GuidType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.GuidType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.InterfaceType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.InterfaceType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..07ca7a2 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.InterfaceType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.InterfaceType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
-#pragma warning restore
\ No newline at end of file
+#pragma warning restore
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.InternalClassGeneratesPublicProperty#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.InternalClassGeneratesPublicProperty#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
new file mode 100644
index 0000000..f529f0c
--- /dev/null
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.InternalClassGeneratesPublicProperty#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -0,0 +1,28 @@
+//HintName: ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.cs
+// Copyright (c) 2026 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+// <auto-generated/>
+#pragma warning disable
+#nullable enable
+namespace ReactiveUI.SourceGenerators;
+
+/// <summary>
+/// ReactiveAttribute.
+/// </summary>
+/// <seealso cref="Attribute" />
+[global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
+#nullable restore
+#pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.InternalClassGeneratesPublicProperty#TestNs.ViewModel.BindableDerivedList.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.InternalClassGeneratesPublicProperty#TestNs.ViewModel.BindableDerivedList.g.verified.cs
new file mode 100644
index 0000000..666ec0d
--- /dev/null
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.InternalClassGeneratesPublicProperty#TestNs.ViewModel.BindableDerivedList.g.verified.cs
@@ -0,0 +1,21 @@
+//HintName: TestNs.ViewModel.BindableDerivedList.g.cs
+// <auto-generated/>
+using System.Collections.ObjectModel;
+using DynamicData;
+using ReactiveUI;
+
+#pragma warning disable
+#nullable enable
+
+namespace TestNs
+{
+    
+    internal partial class ViewModel
+    {
+        /// <inheritdoc cref="_theList"/>
+        [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+        public global::System.Collections.ObjectModel.ReadOnlyObservableCollection<string>? TheList => _theList;
+    }
+}
+#nullable restore
+#pragma warning restore
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.MultipleLists#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.MultipleLists#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..f529f0c 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.MultipleLists#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.MultipleLists#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.NestedClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.NestedClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..f529f0c 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.NestedClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.NestedClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.NullableElements#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.NullableElements#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..f529f0c 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.NullableElements#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.NullableElements#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.RecordClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.RecordClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..f529f0c 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.RecordClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.RecordClass#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.StructType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.StructType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..07ca7a2 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.StructType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.StructType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
-#pragma warning restore
\ No newline at end of file
+#pragma warning restore
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.TupleType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.TupleType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..f529f0c 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.TupleType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.TupleType#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.WithReactive#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.WithReactive#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
index 105caa6..f529f0c 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.WithReactive#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/DERIVEDLIST/DerivedListExtTests.WithReactive#ReactiveUI.SourceGenerators.BindableDerivedListAttribute.g.verified.cs
@@ -14,6 +14,15 @@ namespace ReactiveUI.SourceGenerators;
 /// </summary>
 /// <seealso cref="Attribute" />
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
\ No newline at end of file
diff --git a/src/ReactiveUI.SourceGenerator.Tests/UnitTests/DerivedListExtTests.cs b/src/ReactiveUI.SourceGenerator.Tests/UnitTests/DerivedListExtTests.cs
index 1f5939d..370704d 100644
--- a/src/ReactiveUI.SourceGenerator.Tests/UnitTests/DerivedListExtTests.cs
+++ b/src/ReactiveUI.SourceGenerator.Tests/UnitTests/DerivedListExtTests.cs
@@ -402,4 +402,66 @@ public partial class TestVM : ReactiveObject
 
         return TestHelper.TestPass(sourceCode);
     }
+
+    /// <summary>
+    /// Tests BindableDerivedList always generates public properties even for internal classes.
+    /// </summary>
+    /// <returns>A task to monitor the async.</returns>
+    [Test]
+    public Task InternalClassGeneratesPublicProperty()
+    {
+        const string sourceCode = """
+            using System.Collections.ObjectModel;
+            using DynamicData;
+            using ReactiveUI;
+
+            namespace TestNs;
+
+            internal partial class ViewModel : ReactiveObject
+            {
+                [BindableDerivedList]
+                private readonly ReadOnlyObservableCollection<string>? _theList;
+            }
+            """;
+
+        return TestHelper.TestPass(sourceCode);
+    }
+
+    /// <summary>
+    /// Tests BindableDerivedList with all supported property access modifiers.
+    /// </summary>
+    /// <returns>A task to monitor the async.</returns>
+    [Test]
+    public Task AccessModifiers()
+    {
+        const string sourceCode = """
+            using System.Collections.ObjectModel;
+            using DynamicData;
+
+            namespace TestNs;
+
+            public partial class TestVM
+            {
+                [BindableDerivedList(AccessModifier = PropertyAccessModifier.Public)]
+                private ReadOnlyObservableCollection<string>? _publicItems;
+
+                [BindableDerivedList(AccessModifier = PropertyAccessModifier.Protected)]
+                private ReadOnlyObservableCollection<string>? _protectedItems;
+
+                [BindableDerivedList(AccessModifier = PropertyAccessModifier.Internal)]
+                private ReadOnlyObservableCollection<string>? _internalItems;
+
+                [BindableDerivedList(AccessModifier = PropertyAccessModifier.Private)]
+                private ReadOnlyObservableCollection<string>? _privateItems;
+
+                [BindableDerivedList(AccessModifier = PropertyAccessModifier.InternalProtected)]
+                private ReadOnlyObservableCollection<string>? _internalProtectedItems;
+
+                [BindableDerivedList(AccessModifier = PropertyAccessModifier.PrivateProtected)]
+                private ReadOnlyObservableCollection<string>? _privateProtectedItems;
+            }
+            """;
+
+        return TestHelper.TestPass(sourceCode);
+    }
 }
diff --git a/src/ReactiveUI.SourceGenerators.Roslyn/AttributeDefinitions.cs b/src/ReactiveUI.SourceGenerators.Roslyn/AttributeDefinitions.cs
index 9c38ce3..1ee66da 100644
--- a/src/ReactiveUI.SourceGenerators.Roslyn/AttributeDefinitions.cs
+++ b/src/ReactiveUI.SourceGenerators.Roslyn/AttributeDefinitions.cs
@@ -519,7 +519,16 @@ namespace ReactiveUI.SourceGenerators;
 /// <seealso cref="Attribute" />
 [global::System.CodeDom.Compiler.GeneratedCode("{{ReactiveGenerator.GeneratorName}}", "{{ReactiveGenerator.GeneratorVersion}}")]
 [global::System.AttributeUsage(global::System.AttributeTargets.Field, AllowMultiple = false, Inherited = false)]
-internal sealed class BindableDerivedListAttribute : global::System.Attribute;
+internal sealed class BindableDerivedListAttribute : global::System.Attribute
+{
+    /// <summary>
+    /// Gets the AccessModifier of the BindableDerivedList property.
+    /// </summary>
+    /// <value>
+    /// The AccessModifier of the property.
+    /// </value>
+    public PropertyAccessModifier AccessModifier { get; init; }
+}
 #nullable restore
 #pragma warning restore
 """;
diff --git a/src/ReactiveUI.SourceGenerators.Roslyn/BindableDerivedList/BindableDerivedListGenerator.Execute.cs b/src/ReactiveUI.SourceGenerators.Roslyn/BindableDerivedList/BindableDerivedListGenerator.Execute.cs
index 6de2884..a7b037e 100644
--- a/src/ReactiveUI.SourceGenerators.Roslyn/BindableDerivedList/BindableDerivedListGenerator.Execute.cs
+++ b/src/ReactiveUI.SourceGenerators.Roslyn/BindableDerivedList/BindableDerivedListGenerator.Execute.cs
@@ -73,6 +73,19 @@ public sealed partial class BindableDerivedListGenerator
 
         token.ThrowIfCancellationRequested();
 
+        // Get AccessModifier enum value from the attribute
+        var accessModifier = attributeData.GetNamedArgument<int>("AccessModifier") switch
+        {
+            1 => "protected",
+            2 => "internal",
+            3 => "private",
+            4 => "protected internal",
+            5 => "private protected",
+            _ => "public",
+        };
+
+        token.ThrowIfCancellationRequested();
+
         // Get the nullability info for the property
         fieldSymbol.GetNullabilityInfo(
         context.SemanticModel,
@@ -104,7 +117,8 @@ public sealed partial class BindableDerivedListGenerator
             propertyName,
             isReferenceTypeOrUnconstraindTypeParameter,
             includeMemberNotNullOnSetAccessor,
-            forwardedAttributesString),
+            forwardedAttributesString,
+            accessModifier),
             builder.ToImmutable());
     }
 
@@ -177,7 +191,7 @@ private static string GetPropertySyntax(BindableDerivedListInfo propertyInfo)
 $$"""
         /// <inheritdoc cref="{{propertyInfo.FieldName}}"/>
         {{propertyAttributes}}
-        {{propertyInfo.TargetInfo.TargetVisibility}} {{propertyInfo.TypeNameWithNullabilityAnnotations}} {{propertyInfo.PropertyName}} => {{propertyInfo.FieldName}};
+        {{propertyInfo.AccessModifier}} {{propertyInfo.TypeNameWithNullabilityAnnotations}} {{propertyInfo.PropertyName}} => {{propertyInfo.FieldName}};
 """;
     }
 }
diff --git a/src/ReactiveUI.SourceGenerators.Roslyn/BindableDerivedList/Models/BindableDerivedListInfo.cs b/src/ReactiveUI.SourceGenerators.Roslyn/BindableDerivedList/Models/BindableDerivedListInfo.cs
index 921f032..74a4374 100644
--- a/src/ReactiveUI.SourceGenerators.Roslyn/BindableDerivedList/Models/BindableDerivedListInfo.cs
+++ b/src/ReactiveUI.SourceGenerators.Roslyn/BindableDerivedList/Models/BindableDerivedListInfo.cs
@@ -18,4 +18,5 @@ internal sealed record BindableDerivedListInfo(
     string PropertyName,
     bool IsReferenceTypeOrUnconstrainedTypeParameter,
     bool IncludeMemberNotNullOnSetAccessor,
-    EquatableArray<string> ForwardedAttributes);
+    EquatableArray<string> ForwardedAttributes,
+    string AccessModifier);