diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 46d3163..0891f4b 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -3,10 +3,10 @@ on:
   push:
     branches:
       - main
-  pull_request: 
+  pull_request:
     branches:
       - main
-permissions: 
+permissions:
   pull-requests: write #allow benchmark-action to comment on PRs
 jobs:
   build:
@@ -20,7 +20,18 @@ jobs:
         uses: actions/setup-dotnet@v4
 
       - name: Build & test
-        run: dotnet test --configuration Release --report-github
+        run: >-
+          dotnet test --configuration Release --report-github --
+          --coverage --coverage-output-format cobertura
+          --coverage-output coverage.cobertura.xml
+          --results-directory ${{ github.workspace }}/coverage-results
+      - name: Upload coverage to Codecov
+        if: ${{ !cancelled() }}
+        uses: codecov/codecov-action@v5
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: ${{ github.workspace }}/coverage-results/coverage.cobertura.xml
+          fail_ci_if_error: false
       - name: Download previous benchmark data
         uses: actions/cache@v4
         with:
@@ -28,11 +39,10 @@ jobs:
           key: ${{ runner.os }}-benchmark
       - name: Continuous Benchmark
         uses: benchmark-action/github-action-benchmark@v1.20.4
-        with: 
+        with:
           tool: benchmarkdotnet
           output-file-path: src/artifacts/bin/SIL.Harmony.Tests/release/BenchmarkDotNet.Artifacts/results/SIL.Harmony.Tests.DataModelPerformanceBenchmarks-report-full-compressed.json
           external-data-json-path: ./cache/benchmark-data.json
           fail-on-alert: true
           comment-on-alert: true
           github-token: ${{ secrets.GITHUB_TOKEN }}
-          
\ No newline at end of file
diff --git a/Directory.Packages.props b/Directory.Packages.props
index 2217c19..549b010 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -12,6 +12,7 @@
     <PackageVersion Include="SQLitePCLRaw.bundle_e_sqlite3" Version="2.1.12" />
     <!-- Transitively referenced by xunit.v3.mtp-v2; pinned so the MTP v2 runner resolves consistently. -->
     <PackageVersion Include="Microsoft.Testing.Platform" Version="2.0.2" />
+    <PackageVersion Include="Microsoft.Testing.Extensions.CodeCoverage" Version="18.3.1" />
     <PackageVersion Include="Nito.AsyncEx.Coordination" Version="5.1.2" />
     <PackageVersion Include="System.IO.Hashing" Version="10.0.7" />
     <PackageVersion Include="System.Linq.Async" Version="7.0.1" />
diff --git a/codecov.yml b/codecov.yml
new file mode 100644
index 0000000..8ec3603
--- /dev/null
+++ b/codecov.yml
@@ -0,0 +1,12 @@
+# Codecov configuration
+# Coverage is published as status checks only; no PR comment.
+comment: false
+coverage:
+  status:
+    project:
+      default:
+        # report coverage as a check without blocking merges
+        informational: true
+    patch:
+      default:
+        informational: true
diff --git a/src/SIL.Harmony.Tests/SIL.Harmony.Tests.csproj b/src/SIL.Harmony.Tests/SIL.Harmony.Tests.csproj
index a53c443..575f837 100644
--- a/src/SIL.Harmony.Tests/SIL.Harmony.Tests.csproj
+++ b/src/SIL.Harmony.Tests/SIL.Harmony.Tests.csproj
@@ -17,6 +17,7 @@
         <PackageReference Include="Verify.EntityFramework" />
         <PackageReference Include="Verify.XunitV3" />
         <PackageReference Include="xunit.v3.mtp-v2" />
+        <PackageReference Include="Microsoft.Testing.Extensions.CodeCoverage" />
         <PackageReference Include="System.Linq.Async"/>
         <PackageReference Include="linq2db" />
         <PackageReference Include="linq2db.Extensions" />