diff --git a/PdbLibrary/PdbLibrary.cs b/PdbLibrary/PdbLibrary.cs
index 6ce02fb..3c0252a 100644
--- a/PdbLibrary/PdbLibrary.cs
+++ b/PdbLibrary/PdbLibrary.cs
@@ -318,6 +318,18 @@ public PDBFile(FileInfo pdbFileInfo)
                 byte[] bytes = new byte[PdbSignature.signature.Length];
                 int n = fp.Read(bytes, 0, PdbSignature.signature.Length);
 
+                // A Portable PDB (ECMA-335, "BSJB" magic — the format modern .NET Core /
+                // SDK projects emit, including a .NET app's own assembly PDB) is CLI
+                // metadata, not an MSF container. Its debug identity is read from the
+                // metadata "PDB id" instead of the MSF streams; the resulting {GUID}{age}
+                // key matches the one a dump's CodeView record names, so it indexes into
+                // the symsrv store the same way an MSF PDB's key does.
+                if (n >= 4 && bytes[0] == (byte)'B' && bytes[1] == (byte)'S' && bytes[2] == (byte)'J' && bytes[3] == (byte)'B')
+                {
+                    this.GUID = ReadPortableIdentity(pdbFileInfo);
+                    return;
+                }
+
                 if (n != PdbSignature.signature.Length)
                 {
                     throw new Exception("Invalid PDB signature");
@@ -373,6 +385,55 @@ public PDBFile(FileInfo pdbFileInfo)
                 }
             }
         }
+
+#if NET
+        // Portable PDB (BSJB) debug identity: the 16-byte GUID prefix of the metadata
+        // "PDB id" (System.Reflection.Metadata's DebugMetadataHeader.Id), with age fixed
+        // at 1 — the value Roslyn writes into the PE's CodeView RSDS record for portable
+        // PDBs — so GUID.Value() yields the same {GUID}{age} symbol-server key a dump's
+        // PdbStoreKey computes. The GUID bytes are laid out exactly as a System.Guid
+        // constructed from the same 16 bytes formats under "N", matching the store key.
+        //
+        // In-box on the net10.0 target; the netstandard2.0 flavor has no
+        // System.Reflection.Metadata, so portable identity is a .NET-target capability
+        // (the MSF-PDB / PE key extraction stays pure BCL and cross-platform there).
+        private static GUID ReadPortableIdentity(FileInfo pdbFileInfo)
+        {
+            using (FileStream stream = new FileStream(pdbFileInfo.FullName, FileMode.Open, FileAccess.Read))
+            using (var provider = System.Reflection.Metadata.MetadataReaderProvider.FromPortablePdbStream(stream))
+            {
+                var reader = provider.GetMetadataReader();
+                var header = reader.DebugMetadataHeader;
+                if (header == null)
+                {
+                    throw new Exception("Not a portable PDB: file has no debug metadata header");
+                }
+
+                var idBlob = header.Id; // 20-byte PDB id: 16-byte GUID + 4-byte stamp
+                if (idBlob.Length < 16)
+                {
+                    throw new Exception($"Portable PDB id too short: {idBlob.Length} bytes");
+                }
+
+                byte[] id = new byte[idBlob.Length];
+                idBlob.CopyTo(id);
+
+                uint data1 = BitConverter.ToUInt32(id, 0);
+                ushort data2 = BitConverter.ToUInt16(id, 4);
+                ushort data3 = BitConverter.ToUInt16(id, 6);
+                byte[] data4 = new byte[8];
+                Array.Copy(id, 8, data4, 0, 8);
+
+                const uint PortablePdbAge = 1; // Roslyn's fixed RSDS age for portable PDBs
+                return new GUID(data1, data2, data3, data4, PortablePdbAge);
+            }
+        }
+#else
+        private static GUID ReadPortableIdentity(FileInfo pdbFileInfo)
+            => throw new NotSupportedException(
+                "Portable PDB identity requires the .NET (net10.0) target of PdbLibrary; " +
+                "the netstandard2.0 flavor reads only MSF/CodeView PDBs.");
+#endif
     }
 
     public class PEFile
diff --git a/PdbLibrary/PdbLibrary.csproj b/PdbLibrary/PdbLibrary.csproj
index cb65f9d..2a433a1 100644
--- a/PdbLibrary/PdbLibrary.csproj
+++ b/PdbLibrary/PdbLibrary.csproj
@@ -1,27 +1,33 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <!--
-    Retargeted from the legacy net472 project to an SDK-style netstandard2.0
-    library (2026-07): the GUID parser is pure BCL (FileStream + BitConverter),
-    so netstandard2.0 runs unchanged on .NET 10 (BugSplat's cross-platform crash
-    processor consumes it there) while staying consumable by the existing net472
-    NuGet package users. Builds on Windows, macOS, and Linux.
+    Retargeted from the legacy net472 project to an SDK-style library (2026-07).
+    Multi-targeted netstandard2.0;net10.0:
+      - netstandard2.0: the MSF-PDB / PE GUID parser is pure BCL (FileStream +
+        BitConverter), so it runs unchanged on .NET 10 and stays consumable by the
+        existing net472 NuGet package users. Builds on Windows, macOS, and Linux.
+      - net10.0: additionally reads PORTABLE PDB (ECMA-335 "BSJB") debug identity via
+        the in-box System.Reflection.Metadata (see ReadPortableIdentity, #if NET). No
+        package reference is needed — the net10.0 target ships it in the framework, and
+        the netstandard2.0 flavor stays pure BCL (portable identity is a .NET-only
+        capability there).
   -->
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;net10.0</TargetFrameworks>
     <RootNamespace>PdbLibrary</RootNamespace>
     <AssemblyName>PdbLibrary</AssemblyName>
     <LangVersion>latest</LangVersion>
     <Nullable>disable</Nullable>
     <GenerateDocumentationFile>false</GenerateDocumentationFile>
 
-    <!-- NuGet package identity (was in Properties/AssemblyInfo.cs) -->
+    <!-- NuGet package identity (was in Properties/AssemblyInfo.cs). Published (signed)
+         manually from a controlled machine; there is no publish CI in this repo. -->
     <PackageId>PdbLibrary</PackageId>
-    <Version>1.1.0</Version>
+    <Version>1.2.0</Version>
     <Authors>BugSplat</Authors>
     <Company>BugSplat</Company>
     <Product>PdbLibrary</Product>
-    <Description>Extract GUIDs from Windows Executables and Symbol Files</Description>
+    <Description>Extract debug identity (GUID+age) from Windows PE images, MSF/CodeView PDBs, and Portable (ECMA-335) PDBs</Description>
     <Copyright>Copyright BugSplat, All Rights Reserved</Copyright>
   </PropertyGroup>
 
diff --git a/UnitTestPdbLibrary/PdbLibraryTests.cs b/UnitTestPdbLibrary/PdbLibraryTests.cs
index 752614a..1dcc348 100644
--- a/UnitTestPdbLibrary/PdbLibraryTests.cs
+++ b/UnitTestPdbLibrary/PdbLibraryTests.cs
@@ -33,6 +33,19 @@ public void TestPDBFileGuid()
             Assert.That(guid, Is.EqualTo("0C0E0F8243B54897952E4DB3E538A2361"));
         }
 
+        [Test]
+        public void TestPortablePdbGuid()
+        {
+            // A Portable PDB (BSJB) — the format a .NET Core / modern SDK app's own
+            // assembly PDB ships in. Its {GUID}{age} key must equal the one a dump's
+            // CodeView record names, so the backend indexes it into the symsrv store
+            // under the same key bugsplat-cdb later looks it up by. This fixture's key
+            // is the directory it lives under in bugsplat-cdb's data/symbols-core store.
+            PDBFile pdbFile = new PDBFile(new FileInfo(TestData("MyDotNetCrasher.pdb")));
+            string guid = pdbFile.GUID.Value();
+            Assert.That(guid, Is.EqualTo("0023F679780F4F5D8DE2F203E88AB6721"));
+        }
+
         [Test]
         public void TestPEFileGuid()
         {
diff --git a/UnitTestPdbLibrary/testdata/MyDotNetCrasher.pdb b/UnitTestPdbLibrary/testdata/MyDotNetCrasher.pdb
new file mode 100644
index 0000000..a657fff
Binary files /dev/null and b/UnitTestPdbLibrary/testdata/MyDotNetCrasher.pdb differ