diff --git a/PolyShim.Tests/Net50/InterlockedTests.cs b/PolyShim.Tests/Net50/InterlockedTests.cs
new file mode 100644
index 0000000..8743c23
--- /dev/null
+++ b/PolyShim.Tests/Net50/InterlockedTests.cs
@@ -0,0 +1,59 @@
+using System.Threading;
+using FluentAssertions;
+using Xunit;
+
+namespace PolyShim.Tests.Net50;
+
+public class InterlockedTests
+{
+    [Fact]
+    public void And_Test()
+    {
+        // uint
+        uint ui = 0xFFFFFFFF;
+        Interlocked.And(ref ui, 0xAAAAAAAA).Should().Be(0xFFFFFFFF);
+        ui.Should().Be(0xAAAAAAAA);
+
+        // int
+        int i = unchecked((int)0xFFFFFFFF);
+        Interlocked.And(ref i, unchecked((int)0xAAAAAAAA)).Should().Be(unchecked((int)0xFFFFFFFF));
+        i.Should().Be(unchecked((int)0xAAAAAAAA));
+
+        // ulong
+        ulong ul = 0xFFFFFFFFFFFFFFFF;
+        Interlocked.And(ref ul, 0xAAAAAAAAAAAAAAAA).Should().Be(0xFFFFFFFFFFFFFFFF);
+        ul.Should().Be(0xAAAAAAAAAAAAAAAA);
+
+        // long
+        long l = unchecked((long)0xFFFFFFFFFFFFFFFF);
+        Interlocked
+            .And(ref l, unchecked((long)0xAAAAAAAAAAAAAAAA))
+            .Should()
+            .Be(unchecked((long)0xFFFFFFFFFFFFFFFF));
+        l.Should().Be(unchecked((long)0xAAAAAAAAAAAAAAAA));
+    }
+
+    [Fact]
+    public void Or_Test()
+    {
+        // uint
+        uint ui = 0x0000FFFF;
+        Interlocked.Or(ref ui, 0xFFFF0000).Should().Be(0x0000FFFF);
+        ui.Should().Be(0xFFFFFFFF);
+
+        // int
+        int i = 0x0000FFFF;
+        Interlocked.Or(ref i, unchecked((int)0xFFFF0000)).Should().Be(0x0000FFFF);
+        i.Should().Be(unchecked((int)0xFFFFFFFF));
+
+        // ulong
+        ulong ul = 0x00000000FFFFFFFF;
+        Interlocked.Or(ref ul, 0xFFFFFFFF00000000).Should().Be(0x00000000FFFFFFFF);
+        ul.Should().Be(0xFFFFFFFFFFFFFFFF);
+
+        // long
+        long l = 0x00000000FFFFFFFF;
+        Interlocked.Or(ref l, unchecked((long)0xFFFFFFFF00000000)).Should().Be(0x00000000FFFFFFFF);
+        l.Should().Be(unchecked((long)0xFFFFFFFFFFFFFFFF));
+    }
+}
diff --git a/PolyShim/Net50/Interlocked.cs b/PolyShim/Net50/Interlocked.cs
new file mode 100644
index 0000000..576834e
--- /dev/null
+++ b/PolyShim/Net50/Interlocked.cs
@@ -0,0 +1,142 @@
+#if (NETCOREAPP && !NET5_0_OR_GREATER) || (NETFRAMEWORK) || (NETSTANDARD)
+#nullable enable
+// ReSharper disable RedundantUsingDirective
+// ReSharper disable CheckNamespace
+// ReSharper disable InconsistentNaming
+// ReSharper disable PartialTypeWithSinglePart
+
+using System.Diagnostics.CodeAnalysis;
+using System.Threading;
+
+[ExcludeFromCodeCoverage]
+internal static class MemberPolyfills_Net50_Interlocked
+{
+    extension(Interlocked)
+    {
+        // https://learn.microsoft.com/dotnet/api/system.threading.interlocked.and#system-threading-interlocked-and(system-int32@-system-int32)
+        public static int And(ref int location1, int value)
+        {
+            int current,
+                newValue,
+                original;
+            do
+            {
+                current = location1;
+                newValue = current & value;
+                original = Interlocked.CompareExchange(ref location1, newValue, current);
+            } while (original != current);
+
+            return original;
+        }
+
+#if ALLOW_UNSAFE_BLOCKS
+        // https://learn.microsoft.com/dotnet/api/system.threading.interlocked.and#system-threading-interlocked-and(system-uint32@-system-uint32)
+        public static uint And(ref uint location1, uint value)
+        {
+            unsafe
+            {
+                fixed (uint* ptr = &location1)
+                {
+                    int result = Interlocked.And(ref *(int*)ptr, *(int*)&value);
+                    return *(uint*)&result;
+                }
+            }
+        }
+#endif
+
+        // https://learn.microsoft.com/dotnet/api/system.threading.interlocked.and#system-threading-interlocked-and(system-int64@-system-int64)
+        public static long And(ref long location1, long value)
+        {
+            long current,
+                newValue,
+                original;
+            do
+            {
+                current = location1;
+                newValue = current & value;
+                original = Interlocked.CompareExchange(ref location1, newValue, current);
+            } while (original != current);
+
+            return original;
+        }
+
+#if ALLOW_UNSAFE_BLOCKS
+        // https://learn.microsoft.com/dotnet/api/system.threading.interlocked.and#system-threading-interlocked-and(system-uint64@-system-uint64)
+        public static ulong And(ref ulong location1, ulong value)
+        {
+            unsafe
+            {
+                fixed (ulong* ptr = &location1)
+                {
+                    long result = Interlocked.And(ref *(long*)ptr, *(long*)&value);
+                    return *(ulong*)&result;
+                }
+            }
+        }
+#endif
+
+        // https://learn.microsoft.com/dotnet/api/system.threading.interlocked.or#system-threading-interlocked-or(system-int32@-system-int32)
+        public static int Or(ref int location1, int value)
+        {
+            int current,
+                newValue,
+                original;
+            do
+            {
+                current = location1;
+                newValue = current | value;
+                original = Interlocked.CompareExchange(ref location1, newValue, current);
+            } while (original != current);
+
+            return original;
+        }
+
+#if ALLOW_UNSAFE_BLOCKS
+        // https://learn.microsoft.com/dotnet/api/system.threading.interlocked.or#system-threading-interlocked-or(system-uint32@-system-uint32)
+        public static uint Or(ref uint location1, uint value)
+        {
+            unsafe
+            {
+                fixed (uint* ptr = &location1)
+                {
+                    int result = Interlocked.Or(ref *(int*)ptr, *(int*)&value);
+                    return *(uint*)&result;
+                }
+            }
+        }
+#endif
+
+        // https://learn.microsoft.com/dotnet/api/system.threading.interlocked.or#system-threading-interlocked-or(system-int64@-system-int64)
+        public static long Or(ref long location1, long value)
+        {
+            long current,
+                newValue,
+                original;
+            do
+            {
+                current = location1;
+                newValue = current | value;
+                original = Interlocked.CompareExchange(ref location1, newValue, current);
+            } while (original != current);
+
+            return original;
+        }
+
+#if ALLOW_UNSAFE_BLOCKS
+        // https://learn.microsoft.com/dotnet/api/system.threading.interlocked.or#system-threading-interlocked-or(system-uint64@-system-uint64)
+        public static ulong Or(ref ulong location1, ulong value)
+        {
+            unsafe
+            {
+                fixed (ulong* ptr = &location1)
+                {
+                    long result = Interlocked.Or(ref *(long*)ptr, *(long*)&value);
+                    return *(ulong*)&result;
+                }
+            }
+        }
+#endif
+    }
+}
+
+#endif
diff --git a/PolyShim/Signatures.md b/PolyShim/Signatures.md
index 5456834..8a19aca 100644
--- a/PolyShim/Signatures.md
+++ b/PolyShim/Signatures.md
@@ -1,8 +1,8 @@
 # Signatures
 
-- **Total:** 364
+- **Total:** 372
 - **Types:** 78
-- **Members:** 286
+- **Members:** 294
 
 ___
 
@@ -175,6 +175,15 @@ ___
   - [**[struct]**](https://learn.microsoft.com/dotnet/api/system.index) <sup><sub>.NET Core 3.0</sub></sup>
 - `int`
   - [`bool TryParse(string, IFormatProvider?, out int)`](https://learn.microsoft.com/dotnet/api/system.int32.tryparse#system-int32-tryparse(system-string-system-iformatprovider-system-int32@)) <sup><sub>.NET 7.0</sub></sup>
+- `Interlocked`
+  - [`int And(ref int, int)`](https://learn.microsoft.com/dotnet/api/system.threading.interlocked.and#system-threading-interlocked-and(system-int32@-system-int32)) <sup><sub>.NET 5.0</sub></sup>
+  - [`int Or(ref int, int)`](https://learn.microsoft.com/dotnet/api/system.threading.interlocked.or#system-threading-interlocked-or(system-int32@-system-int32)) <sup><sub>.NET 5.0</sub></sup>
+  - [`long And(ref long, long)`](https://learn.microsoft.com/dotnet/api/system.threading.interlocked.and#system-threading-interlocked-and(system-int64@-system-int64)) <sup><sub>.NET 5.0</sub></sup>
+  - [`long Or(ref long, long)`](https://learn.microsoft.com/dotnet/api/system.threading.interlocked.or#system-threading-interlocked-or(system-int64@-system-int64)) <sup><sub>.NET 5.0</sub></sup>
+  - [`uint And(ref uint, uint)`](https://learn.microsoft.com/dotnet/api/system.threading.interlocked.and#system-threading-interlocked-and(system-uint32@-system-uint32)) <sup><sub>.NET 5.0</sub></sup>
+  - [`uint Or(ref uint, uint)`](https://learn.microsoft.com/dotnet/api/system.threading.interlocked.or#system-threading-interlocked-or(system-uint32@-system-uint32)) <sup><sub>.NET 5.0</sub></sup>
+  - [`ulong And(ref ulong, ulong)`](https://learn.microsoft.com/dotnet/api/system.threading.interlocked.and#system-threading-interlocked-and(system-uint64@-system-uint64)) <sup><sub>.NET 5.0</sub></sup>
+  - [`ulong Or(ref ulong, ulong)`](https://learn.microsoft.com/dotnet/api/system.threading.interlocked.or#system-threading-interlocked-or(system-uint64@-system-uint64)) <sup><sub>.NET 5.0</sub></sup>
 - `IntPtr`
   - [`bool TryParse(string, IFormatProvider?, out IntPtr)`](https://learn.microsoft.com/dotnet/api/system.intptr.tryparse#system-intptr-tryparse(system-string-system-iformatprovider-system-intptr@)) <sup><sub>.NET 7.0</sub></sup>
   - [`bool TryParse(string?, out IntPtr)`](https://learn.microsoft.com/dotnet/api/system.intptr.tryparse#system-intptr-tryparse(system-string-system-intptr@)) <sup><sub>.NET 5.0</sub></sup>