diff --git a/SharepointToolbox.Tests/Helpers/PermissionLevelMappingTests.cs b/SharepointToolbox.Tests/Helpers/PermissionLevelMappingTests.cs
new file mode 100644
index 0000000..ac6f035
--- /dev/null
+++ b/SharepointToolbox.Tests/Helpers/PermissionLevelMappingTests.cs
@@ -0,0 +1,87 @@
+using SharepointToolbox.Core.Helpers;
+using SharepointToolbox.Core.Models;
+
+namespace SharepointToolbox.Tests.Helpers;
+
+/// <summary>
+/// Unit tests for PermissionLevelMapping static helper.
+/// SIMP-01: Validates mapping correctness for known roles, unknown fallback,
+/// case insensitivity, semicolon splitting, risk ranking, and label generation.
+/// </summary>
+public class PermissionLevelMappingTests
+{
+    [Theory]
+    [InlineData("Full Control", RiskLevel.High)]
+    [InlineData("Site Collection Administrator", RiskLevel.High)]
+    [InlineData("Contribute", RiskLevel.Medium)]
+    [InlineData("Edit", RiskLevel.Medium)]
+    [InlineData("Design", RiskLevel.Medium)]
+    [InlineData("Approve", RiskLevel.Medium)]
+    [InlineData("Manage Hierarchy", RiskLevel.Medium)]
+    [InlineData("Read", RiskLevel.Low)]
+    [InlineData("Restricted Read", RiskLevel.Low)]
+    [InlineData("View Only", RiskLevel.ReadOnly)]
+    [InlineData("Restricted View", RiskLevel.ReadOnly)]
+    public void GetMapping_KnownRoles_ReturnsCorrectRiskLevel(string roleName, RiskLevel expected)
+    {
+        var result = PermissionLevelMapping.GetMapping(roleName);
+        Assert.Equal(expected, result.RiskLevel);
+        Assert.NotEmpty(result.Label);
+    }
+
+    [Fact]
+    public void GetMapping_UnknownRole_ReturnsMediumRiskWithRawName()
+    {
+        var result = PermissionLevelMapping.GetMapping("Custom Permission Level");
+        Assert.Equal(RiskLevel.Medium, result.RiskLevel);
+        Assert.Equal("Custom Permission Level", result.Label);
+    }
+
+    [Fact]
+    public void GetMapping_CaseInsensitive()
+    {
+        var lower = PermissionLevelMapping.GetMapping("full control");
+        var upper = PermissionLevelMapping.GetMapping("FULL CONTROL");
+        Assert.Equal(RiskLevel.High, lower.RiskLevel);
+        Assert.Equal(RiskLevel.High, upper.RiskLevel);
+    }
+
+    [Fact]
+    public void GetMappings_SemicolonDelimited_SplitsAndMaps()
+    {
+        var results = PermissionLevelMapping.GetMappings("Full Control; Read");
+        Assert.Equal(2, results.Count);
+        Assert.Equal(RiskLevel.High, results[0].RiskLevel);
+        Assert.Equal(RiskLevel.Low, results[1].RiskLevel);
+    }
+
+    [Fact]
+    public void GetMappings_EmptyString_ReturnsEmpty()
+    {
+        var results = PermissionLevelMapping.GetMappings("");
+        Assert.Empty(results);
+    }
+
+    [Fact]
+    public void GetHighestRisk_MultipleLevels_ReturnsHighest()
+    {
+        // Full Control (High) + Read (Low) => High
+        var risk = PermissionLevelMapping.GetHighestRisk("Full Control; Read");
+        Assert.Equal(RiskLevel.High, risk);
+    }
+
+    [Fact]
+    public void GetHighestRisk_SingleReadOnly_ReturnsReadOnly()
+    {
+        var risk = PermissionLevelMapping.GetHighestRisk("View Only");
+        Assert.Equal(RiskLevel.ReadOnly, risk);
+    }
+
+    [Fact]
+    public void GetSimplifiedLabels_JoinsLabels()
+    {
+        var labels = PermissionLevelMapping.GetSimplifiedLabels("Contribute; Read");
+        Assert.Contains("Can edit files and list items", labels);
+        Assert.Contains("Can view files and pages", labels);
+    }
+}
diff --git a/SharepointToolbox.Tests/Models/PermissionSummaryBuilderTests.cs b/SharepointToolbox.Tests/Models/PermissionSummaryBuilderTests.cs
new file mode 100644
index 0000000..6c4724b
--- /dev/null
+++ b/SharepointToolbox.Tests/Models/PermissionSummaryBuilderTests.cs
@@ -0,0 +1,82 @@
+using SharepointToolbox.Core.Models;
+
+namespace SharepointToolbox.Tests.Models;
+
+/// <summary>
+/// Unit tests for PermissionSummaryBuilder and SimplifiedPermissionEntry.
+/// SIMP-02: Validates summary aggregation, risk-level grouping, distinct user counting,
+/// and SimplifiedPermissionEntry wrapping behavior.
+/// </summary>
+public class PermissionSummaryBuilderTests
+{
+    private static PermissionEntry MakeEntry(string permLevels, string users = "User1", string logins = "user1@test.com") =>
+        new PermissionEntry(
+            ObjectType: "Site",
+            Title: "Test",
+            Url: "https://test.sharepoint.com",
+            HasUniquePermissions: true,
+            Users: users,
+            UserLogins: logins,
+            PermissionLevels: permLevels,
+            GrantedThrough: "Direct Permissions",
+            PrincipalType: "User");
+
+    [Fact]
+    public void Build_ReturnsAllFourRiskLevels()
+    {
+        var entries = SimplifiedPermissionEntry.WrapAll(new[]
+        {
+            MakeEntry("Full Control"),
+            MakeEntry("Contribute"),
+            MakeEntry("Read"),
+            MakeEntry("View Only")
+        });
+
+        var summaries = PermissionSummaryBuilder.Build(entries);
+
+        Assert.Equal(4, summaries.Count);
+        Assert.Contains(summaries, s => s.RiskLevel == RiskLevel.High && s.Count == 1);
+        Assert.Contains(summaries, s => s.RiskLevel == RiskLevel.Medium && s.Count == 1);
+        Assert.Contains(summaries, s => s.RiskLevel == RiskLevel.Low && s.Count == 1);
+        Assert.Contains(summaries, s => s.RiskLevel == RiskLevel.ReadOnly && s.Count == 1);
+    }
+
+    [Fact]
+    public void Build_EmptyCollection_ReturnsZeroCounts()
+    {
+        var summaries = PermissionSummaryBuilder.Build(Array.Empty<SimplifiedPermissionEntry>());
+
+        Assert.Equal(4, summaries.Count);
+        Assert.All(summaries, s => Assert.Equal(0, s.Count));
+    }
+
+    [Fact]
+    public void Build_CountsDistinctUsers()
+    {
+        var entries = SimplifiedPermissionEntry.WrapAll(new[]
+        {
+            MakeEntry("Full Control", "Alice", "alice@test.com"),
+            MakeEntry("Full Control", "Bob", "bob@test.com"),
+            MakeEntry("Full Control", "Alice", "alice@test.com"),  // duplicate user
+        });
+
+        var summaries = PermissionSummaryBuilder.Build(entries);
+        var high = summaries.Single(s => s.RiskLevel == RiskLevel.High);
+
+        Assert.Equal(3, high.Count);          // 3 entries
+        Assert.Equal(2, high.DistinctUsers);   // 2 distinct users
+    }
+
+    [Fact]
+    public void SimplifiedPermissionEntry_WrapAll_PreservesInner()
+    {
+        var original = MakeEntry("Contribute");
+        var wrapped = SimplifiedPermissionEntry.WrapAll(new[] { original });
+
+        Assert.Single(wrapped);
+        Assert.Same(original, wrapped[0].Inner);
+        Assert.Equal("Contribute", wrapped[0].PermissionLevels);
+        Assert.Equal(RiskLevel.Medium, wrapped[0].RiskLevel);
+        Assert.Contains("Can edit", wrapped[0].SimplifiedLabels);
+    }
+}