diff --git a/src/AR.Iec61850/Mms/MmsG27NativeEnvelopeBoundRuntimePlanner.cs b/src/AR.Iec61850/Mms/MmsG27NativeEnvelopeBoundRuntimePlanner.cs
new file mode 100644
index 00000000..15c20888
--- /dev/null
+++ b/src/AR.Iec61850/Mms/MmsG27NativeEnvelopeBoundRuntimePlanner.cs
@@ -0,0 +1,65 @@
+using AR.Iec61850.Acse;
+using AR.Iec61850.Discovery;
+
+namespace AR.Iec61850.Mms;
+
+/// <summary>
+/// Field-stability wrapper for the P1.7 native per-IED capability runtime.
+///
+/// A native dchg + cleanup witness proves that dynamic reporting may be generalized to
+/// fresh exact-resolved members, but it does not prove that a larger NamedVariableList than
+/// the G2.3 accepted envelope is safe for the IED association. Runtime therefore keeps the
+/// general member-capability semantics while capping each individual Dynamic DataSet to the
+/// physically proven G2.3 member-count envelope.
+///
+/// This planner does not alter identity/witness authorization, RCB availability, deterministic
+/// AR_HYB identity, ProductionEligible state, or polling fallback. Those remain owned by the
+/// existing stable P1.7 planner and its downstream hybrid planner.
+/// </summary>
+public static class MmsGuardedDynamicReportNativeFieldCapabilityEnvelopeBoundRuntimePlanner
+{
+    public static MmsCapabilityAwareHybridReportAcquisitionPlan Build(
+        Iec61850SignalCatalogDocument catalog,
+        IEnumerable<Iec61850SignalDescriptor> requestedSignals,
+        MmsReportInventory inventory,
+        MmsRcbAvailabilityResult availability,
+        MmsIedModelDirectory liveDirectory,
+        AcseMmsNegotiatedCapabilities? negotiatedCapabilities,
+        MmsHybridReportAcquisitionOptions? options,
+        MmsDynamicReportGuardedRuntimePlanningContext sourceContext,
+        MmsDynamicReportNativeFieldCapabilityEvidence evidence)
+    {
+        ArgumentNullException.ThrowIfNull(sourceContext);
+        options ??= new MmsHybridReportAcquisitionOptions();
+
+        var provenEnvelopeMembers = sourceContext.Profile.ProvenSafeMemberCount;
+        var boundedMembers = provenEnvelopeMembers > 1
+            ? Math.Min(options.MaxDynamicMembersPerReport, provenEnvelopeMembers)
+            : options.MaxDynamicMembersPerReport;
+
+        var boundedOptions = new MmsHybridReportAcquisitionOptions
+        {
+            MaxStaticReportPlans = options.MaxStaticReportPlans,
+            MaxDynamicReportPlans = options.MaxDynamicReportPlans,
+            MaxDynamicMembersPerReport = boundedMembers,
+            RequireExactAvailabilityEvidence = options.RequireExactAvailabilityEvidence,
+            AllowCallerOwnedReports = options.AllowCallerOwnedReports,
+            AllowStaticBrcb = options.AllowStaticBrcb,
+            AllowStaticUrcb = options.AllowStaticUrcb,
+            AllowDynamicBrcb = options.AllowDynamicBrcb,
+            AllowDynamicUrcb = options.AllowDynamicUrcb,
+            AllowPollingFallback = options.AllowPollingFallback
+        };
+
+        return MmsGuardedDynamicReportNativeFieldCapabilityStableRuntimePlanner.Build(
+            catalog,
+            requestedSignals,
+            inventory,
+            availability,
+            liveDirectory,
+            negotiatedCapabilities,
+            boundedOptions,
+            sourceContext,
+            evidence);
+    }
+}
diff --git a/tests/AR.Iec61850.Tests/Mms/MmsG27NativeEnvelopeBoundRuntimeTests.cs b/tests/AR.Iec61850.Tests/Mms/MmsG27NativeEnvelopeBoundRuntimeTests.cs
new file mode 100644
index 00000000..4c81122d
--- /dev/null
+++ b/tests/AR.Iec61850.Tests/Mms/MmsG27NativeEnvelopeBoundRuntimeTests.cs
@@ -0,0 +1,252 @@
+using AR.Iec61850.Acse;
+using AR.Iec61850.Discovery;
+using AR.Iec61850.Mms;
+
+namespace AR.Iec61850.Tests.Mms;
+
+public sealed class MmsG27NativeEnvelopeBoundRuntimeTests
+{
+    [Fact]
+    public void NativeRuntime_GenericLimitAbovePhysicalEnvelope_UsesMoreBoundedGroupsInsteadOfOversizedDataSet()
+    {
+        var signals = Enumerable.Range(1, 5).Select(Signal).ToArray();
+        var profile = NativeProfile();
+        var context = new MmsDynamicReportGuardedRuntimePlanningContext
+        {
+            Profile = profile,
+            CurrentIdentity = Identity()
+        };
+
+        var plan = MmsGuardedDynamicReportNativeFieldCapabilityEnvelopeBoundRuntimePlanner.Build(
+            new Iec61850SignalCatalogDocument
+            {
+                IedName = "G27_BOUND_IED",
+                Source = "P1.7 envelope-bound runtime fixture",
+                Signals = signals
+            },
+            signals,
+            DynamicInventory(1, 2, 3),
+            DynamicAvailability(1, 2, 3),
+            Directory(1, 2, 3, 4, 5),
+            new AcseMmsNegotiatedCapabilities
+            {
+                IsDecoded = true,
+                SupportsWrite = true,
+                SupportsDefineNamedVariableList = true,
+                SupportsDeleteNamedVariableList = true
+            },
+            new MmsHybridReportAcquisitionOptions
+            {
+                MaxDynamicReportPlans = 8,
+                MaxDynamicMembersPerReport = 64,
+                AllowStaticBrcb = false,
+                AllowStaticUrcb = false,
+                AllowDynamicBrcb = false,
+                AllowDynamicUrcb = true,
+                AllowCallerOwnedReports = false,
+                AllowPollingFallback = true,
+                RequireExactAvailabilityEvidence = true
+            },
+            context,
+            NativeEvidence());
+
+        Assert.False(plan.AutomaticDynamicActivationQuarantined);
+        Assert.Equal(5, plan.AcquisitionPlan.DynamicUrcbSignalCount);
+        Assert.Equal(0, plan.AcquisitionPlan.PollingFallbackSignalCount);
+
+        var groups = plan.AcquisitionPlan.Segments
+            .Where(segment => segment.Kind == MmsHybridAcquisitionKind.DynamicUrcb)
+            .ToArray();
+
+        Assert.Equal(3, groups.Length);
+        Assert.Equal(new[] { 2, 2, 1 }, groups.Select(group => group.Signals.Count).ToArray());
+        Assert.All(groups, group => Assert.True(group.Signals.Count <= profile.ProvenSafeMemberCount));
+        Assert.All(groups, group => Assert.Contains("AR_HYB_", group.DataSetReference, StringComparison.OrdinalIgnoreCase));
+    }
+
+    private static MmsDynamicReportQualificationProfile NativeProfile()
+    {
+        var members = new[] { Member(1), Member(2) };
+        var assessment = MmsDynamicDataSetQualificationLadder.Assess(
+        [
+            new MmsDynamicDataSetQualificationAttemptEvidence
+            {
+                AttemptId = "g27-bound-envelope",
+                ObservedAtUtc = Time(1),
+                DataSetReference = ProvenDataSetReference,
+                MemberReferences = members,
+                DefineRequestByteCount = 220,
+                NegotiatedMaxMmsPduSize = 65000,
+                RequestWithinKnownNegotiatedPdu = true,
+                IsSuccess = true,
+                FailureStage = MmsDynamicDataSetQualificationFailureStage.None,
+                DynamicMutationAttempted = true,
+                AssociationSurvived = true,
+                CleanupSucceeded = true
+            }
+        ]);
+        var envelope = MmsDynamicDataSetQualificationLadder.AcceptExactEnvelope(assessment, "g27-bound-envelope");
+        var profile = MmsDynamicReportQualificationProfilePolicy.CreateEnvelopeQualifiedProfile(
+            Identity(), envelope, assessment, null, "g27-bound-envelope-evidence", Time(2));
+
+        var activated = MmsDynamicReportQualificationProfilePolicy.RecordRcbActivationProof(
+            profile,
+            Identity(),
+            new MmsDynamicRcbActivationProof
+            {
+                EvidenceId = ActivationEvidenceId,
+                ObservedAtUtc = Time(3),
+                RcbReference = DynamicRcb(1),
+                DataSetReference = ProvenDataSetReference,
+                MemberReferences = members,
+                FreshRcbAvailabilityVerified = true,
+                DataSetReadbackVerified = true,
+                RcbDataSetBindingAccepted = true,
+                RptEnaAccepted = true,
+                AssociationHealthyAfterActivation = true
+            });
+
+        return MmsDynamicReportQualificationProfilePolicy.RecordInformationReportProof(
+            activated,
+            Identity(),
+            new MmsDynamicInformationReportProof
+            {
+                EvidenceId = ReportEvidenceId,
+                ObservedAtUtc = Time(4),
+                RcbReference = DynamicRcb(1),
+                DataSetReference = ProvenDataSetReference,
+                MemberReferences = members,
+                Kind = MmsDynamicInformationReportKind.DataChange,
+                ActualInformationReportReceived = true,
+                ReportIdentityVerified = true,
+                ExactMemberMappingVerified = true,
+                AssociationHealthyAfterReport = true,
+                ReportAuthoritativePointCount = 1
+            });
+    }
+
+    private static MmsDynamicReportNativeFieldCapabilityEvidence NativeEvidence()
+        => new()
+        {
+            EvidenceId = "g27-bound-native-witness",
+            ObservedAtUtc = Time(5),
+            StableIdentityKey = Identity().StableIdentityKey,
+            ModelFingerprint = Identity().ModelFingerprint,
+            ProfileRevision = Identity().ProfileRevision,
+            RcbReference = DynamicRcb(1),
+            DataSetReference = ProvenDataSetReference,
+            RcbActivationEvidenceId = ActivationEvidenceId,
+            InformationReportEvidenceId = ReportEvidenceId,
+            IncludedMemberReferences = [Member(1)],
+            ActualInformationReportReceived = true,
+            DataChangeReasonVerified = true,
+            GeneralInterrogationDisabled = true,
+            ExactMemberMappingVerified = true,
+            AssociationHealthyAfterReport = true,
+            MonitorCleanupSucceeded = true,
+            ProofFieldRestoreSucceeded = true,
+            FreshCleanupClosureSucceeded = true
+        };
+
+    private static MmsDynamicReportIedIdentity Identity()
+        => new()
+        {
+            StableIdentityKey = "ied:g27:bound",
+            ModelFingerprint = "sha256:g27-bound-model",
+            Manufacturer = "Example",
+            Model = "BoundIED",
+            FirmwareRevision = "1.0.0",
+            ProfileRevision = "cfg-bound"
+        };
+
+    private static MmsReportInventory DynamicInventory(params int[] indexes)
+    {
+        var inventory = new MmsReportInventory();
+        foreach (var index in indexes)
+        {
+            inventory.ReportControls.Add(new MmsReportControlCandidate
+            {
+                Domain = "LD0",
+                LogicalNode = "LLN0",
+                FunctionalConstraint = "RP",
+                Name = $"Unbuffer{index:00}",
+                Reference = DynamicRcb(index),
+                Buffered = false,
+                DataSetReference = string.Empty,
+                DataSetProbeState = MmsRcbDataSetProbeState.ReadSucceeded,
+                EnabledState = "false",
+                ReservationState = "false",
+                TriggerOptions = "dchg",
+                ReportId = $"Unbuffer{index:00}",
+                ConfRev = "1"
+            });
+        }
+        return inventory;
+    }
+
+    private static MmsRcbAvailabilityResult DynamicAvailability(params int[] indexes)
+        => new()
+        {
+            CheckedAtUtc = Time(10),
+            ReportControls = indexes.Select(index => new MmsRcbAvailabilitySnapshot
+            {
+                Reference = DynamicRcb(index),
+                Domain = "LD0",
+                LogicalNode = "LLN0",
+                Name = $"Unbuffer{index:00}",
+                Mode = "URCB",
+                Buffered = false,
+                DataSetReference = string.Empty,
+                DataSetProbeState = MmsRcbDataSetProbeState.ReadSucceeded,
+                ReportId = $"Unbuffer{index:00}",
+                ConfRev = "1",
+                EnabledState = "false",
+                ReservationState = "false",
+                TriggerOptions = "dchg",
+                DataSetDirectoryRead = false,
+                DataSetDirectorySuccess = false,
+                DataSetMemberCount = 0,
+                DataSetMembers = Array.Empty<MmsDataSetDirectoryMember>(),
+                Availability = MmsRcbOperationalAvailability.NoDataSet,
+                Confidence = MmsRcbAvailabilityConfidence.Exact,
+                Reason = "P1.7 exact empty URCB fixture",
+                Attributes = ["DatSet", "RptEna", "TrgOps", "OptFlds", "Resv"]
+            }).ToArray()
+        };
+
+    private static MmsIedModelDirectory Directory(params int[] indexes)
+        => new(indexes.Select(index => new MmsFcResolvedPoint
+        {
+            Domain = "LD0",
+            LogicalNode = "GGIO1",
+            FunctionalConstraint = "ST",
+            DataObjectPath = $"Ind{index}.stVal",
+            MmsItemName = $"GGIO1$ST$Ind{index}$stVal",
+            Source = "P1.7 synthetic live directory",
+            Confidence = 100
+        }));
+
+    private static Iec61850SignalDescriptor Signal(int index)
+        => new()
+        {
+            DesignReference = $"LD0/GGIO1.Ind{index}.stVal",
+            ObservedReference = $"LD0/GGIO1.Ind{index}.stVal",
+            CanonicalMmsReference = Member(index),
+            EffectiveMmsReference = Member(index),
+            PrimaryValueReference = $"LD0/GGIO1.Ind{index}.stVal",
+            PrimaryValueMmsReference = Member(index),
+            FunctionalConstraint = "ST",
+            SemanticRole = Iec61850DataAttributeSemanticRole.PrimaryValue,
+            IsOperationalCandidate = true,
+            ResolutionStatus = Iec61850SignalCatalogResolutionStatus.DesignAttribute,
+            LiveStatus = Iec61850DesignLiveStatus.Exact
+        };
+
+    private static string DynamicRcb(int index) => $"LD0/LLN0.RP.Unbuffer{index:00}";
+    private static string Member(int index) => $"LD0/GGIO1$ST$Ind{index}$stVal";
+    private static DateTimeOffset Time(int minutes) => DateTimeOffset.Parse("2026-09-03T00:00:00Z").AddMinutes(minutes);
+
+    private const string ProvenDataSetReference = "LD0/LLN0.AR_G27_BOUND";
+    private const string ActivationEvidenceId = "g27-bound-activation";
+    private const string ReportEvidenceId = "g27-bound-dchg-report";
+}