diff --git a/lib/graph/apply-proposal.js b/lib/graph/apply-proposal.js
index 2b9ddf1..cf5b542 100644
--- a/lib/graph/apply-proposal.js
+++ b/lib/graph/apply-proposal.js
@@ -4401,3 +4401,120 @@ export function applyValidatedProposal({
     reasoningState: nextReasoningState,
   };
 }
+
+// ── 60B.61 — decision remaining-material-factor detection ──
+
+const TERMINAL_STATUSES = ["known", "resolved", "contradicted"];
+
+function isUnresolvedUnknown(node) {
+  return (
+    node.kind === "unknown" && !TERMINAL_STATUSES.includes(node.status)
+  );
+}
+
+export function hasRemainingMaterialFactors(decisionNodeId, graph) {
+  return countRemainingMaterialFactors(decisionNodeId, graph) > 0;
+}
+
+// ── 60B.61 — count remaining material factors for a decision node ──
+
+/**
+ * Count unresolved unknown nodes that remain material to a decision
+ * after all proposal updates have been applied.
+ *
+ * Routes (mirrors hasRemainingMaterialFactors but returns count):
+ *  A: hierarchy   – unresolved unknown is ancestor/descendant of decision via parentId / childIds
+ *  B: direct dep  – unresolved unknown depends_on the decision node
+ *  C: consequence  – unresolved unknown affects/may_cause/causes an option contained in the decision
+ *  D: containment  – unresolved unknown ->[contained_in]-> option ->[contained_in]-> decision
+ */
+export function countRemainingMaterialFactors(decisionNodeId, graph) {
+  const nodes = graph.nodes || [];
+  const edges = graph.edges || [];
+  const nodesById = new Map(nodes.map((n) => [n.id, n]));
+
+  const decisionNode = nodesById.get(decisionNodeId);
+  if (!decisionNode) return 0;
+
+  // Collect all option IDs that belong to this decision via contained_in
+  const decisionOptionIds = new Set();
+  for (const edge of edges) {
+    if (
+      edge.relationship === "contained_in" &&
+      edge.toNodeId === decisionNodeId
+    ) {
+      decisionOptionIds.add(edge.fromNodeId);
+    }
+  }
+
+  // Build parentId upward chain for Route A
+  function getAncestorNode(nodeId, depth = 0) {
+    if (depth > 50) return null;
+    const n = nodesById.get(nodeId);
+    if (!n?.parentId) return null;
+    return nodesById.get(n.parentId) ?? null;
+  }
+
+  // All material factor node IDs (deduplicated)
+  const materialFactorIds = new Set();
+
+  // Route A: hierarchy (parentId chain reaches the decision — unknown is descendant)
+  for (const node of nodes) {
+    if (node.id === decisionNodeId || !isUnresolvedUnknown(node)) continue;
+    let currentParent = getAncestorNode(node.id);
+    while (currentParent) {
+      if (currentParent.id === decisionNodeId) {
+        materialFactorIds.add(node.id);
+        break;
+      }
+      currentParent = getAncestorNode(currentParent.id);
+    }
+  }
+
+  // Route A (cont.): direct childIds membership
+  for (const childId of decisionNode.childIds || []) {
+    const childNode = nodesById.get(childId);
+    if (childNode && isUnresolvedUnknown(childNode)) {
+      materialFactorIds.add(childId);
+    }
+  }
+
+  // Route B: direct dependency edge TO the decision
+  for (const edge of edges) {
+    if (edge.toNodeId !== decisionNodeId || edge.relationship !== "depends_on") continue;
+    const source = nodesById.get(edge.fromNodeId);
+    if (source && isUnresolvedUnknown(source)) {
+      materialFactorIds.add(edge.fromNodeId);
+    }
+  }
+
+  // Route C: consequence edge to option → contained_in → decision
+  for (const edge of edges) {
+    if (edge.relationship !== "affects" && edge.relationship !== "may_cause" && edge.relationship !== "causes") continue;
+    const source = nodesById.get(edge.fromNodeId);
+    const targetOptionId = edge.toNodeId;
+    if (!source || !isUnresolvedUnknown(source) || !decisionOptionIds.has(targetOptionId)) continue;
+    materialFactorIds.add(edge.fromNodeId);
+  }
+
+  // Route D: containment path — unknown ->[contained_in]-> option ->[contained_in]-> decision
+  for (const edge of edges) {
+    if (edge.relationship !== "contained_in") continue;
+    const fromNode = nodesById.get(edge.fromNodeId);
+    if (!fromNode || !isUnresolvedUnknown(fromNode)) continue;
+
+    // Check if the target is an option contained in the decision
+    for (const innerEdge of edges) {
+      if (
+        innerEdge.relationship === "contained_in" &&
+        innerEdge.fromNodeId === edge.toNodeId &&
+        innerEdge.toNodeId === decisionNodeId
+      ) {
+        materialFactorIds.add(edge.fromNodeId);
+        break;
+      }
+    }
+  }
+
+  return materialFactorIds.size;
+}
diff --git a/tests/graph/apply-proposal.test.js b/tests/graph/apply-proposal.test.js
index 9d35007..9afd32c 100644
--- a/tests/graph/apply-proposal.test.js
+++ b/tests/graph/apply-proposal.test.js
@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { applyValidatedProposal } from "@/lib/graph/apply-proposal.js";
+import { applyValidatedProposal, hasRemainingMaterialFactors } from "@/lib/graph/apply-proposal.js";
 import { makeEdge, makeGraph, makeNode } from "@/lib/graph/schema.js";
 import {
   selectActiveUnknownCandidate,
@@ -5008,3 +5008,357 @@ describe("60B.49 — reconciles updated-to-resolved unknown into resolvedUnknown
     }
   });
 });
+
+describe("60B.61 — decision remaining-material-factor detection", () => {
+
+  // Test 1 — exact 60B.56 containment-only factor
+  it("returns true when unresolved unknown is contained_in an option of the decision", () => {
+    const decision = makeNode({
+      id: "n_decision",
+      label: "Decision",
+      kind: "unknown",
+      status: "unknown",
+    });
+    const optA = makeNode({
+      id: "opt_a",
+      label: "Option A",
+      kind: "option",
+      status: "known",
+    });
+    const factor = makeNode({
+      id: "n_factor",
+      label: "Material factor",
+      kind: "unknown",
+      status: "unknown",
+    });
+
+    const graph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision, optA, factor],
+      edges: [
+        makeEdge({ fromNodeId: optA.id, toNodeId: decision.id, relationship: "contained_in" }),
+        makeEdge({ fromNodeId: factor.id, toNodeId: optA.id, relationship: "contained_in" }),
+      ],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(true);
+  });
+
+  // Test 2 — same factor resolved
+  it("returns false when the containment-only factor is resolved", () => {
+    const decision = makeNode({
+      id: "n_decision",
+      label: "Decision",
+      kind: "unknown",
+      status: "unknown",
+    });
+    const optA = makeNode({
+      id: "opt_a",
+      label: "Option A",
+      kind: "option",
+      status: "known",
+    });
+    const factor = makeNode({
+      id: "n_factor",
+      label: "Resolved factor",
+      kind: "unknown",
+      status: "resolved",
+    });
+
+    const graph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision, optA, factor],
+      edges: [
+        makeEdge({ fromNodeId: optA.id, toNodeId: decision.id, relationship: "contained_in" }),
+        makeEdge({ fromNodeId: factor.id, toNodeId: optA.id, relationship: "contained_in" }),
+      ],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(false);
+  });
+
+  // Test 3 — consequence-linked factor (Route C)
+  it("returns true when unresolved unknown has affects/may_cause/causes to an option of the decision", () => {
+    const decision = makeNode({
+      id: "n_decision",
+      label: "Decision",
+      kind: "unknown",
+      status: "unknown",
+    });
+    const optA = makeNode({
+      id: "opt_a",
+      label: "Option A",
+      kind: "option",
+      status: "known",
+    });
+    const factor = makeNode({
+      id: "n_factor",
+      label: "Consequence factor",
+      kind: "unknown",
+      status: "unknown",
+    });
+
+    const graph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision, optA, factor],
+      edges: [
+        makeEdge({ fromNodeId: optA.id, toNodeId: decision.id, relationship: "contained_in" }),
+        makeEdge({ fromNodeId: factor.id, toNodeId: optA.id, relationship: "may_cause" }),
+      ],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(true);
+  });
+
+  // Test 4 — direct dependency (Route B)
+  it("returns true when unresolved unknown directly depends_on the decision, and false once resolved", () => {
+    const decision = makeNode({
+      id: "n_decision",
+      label: "Decision",
+      kind: "unknown",
+      status: "unknown",
+    });
+    const depUnknown = makeNode({
+      id: "n_dep",
+      label: "Dependency unknown",
+      kind: "unknown",
+      status: "unknown",
+    });
+
+    const graph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision, depUnknown],
+      edges: [
+        makeEdge({ fromNodeId: depUnknown.id, toNodeId: decision.id, relationship: "depends_on" }),
+      ],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(true);
+
+    // Once resolved
+    const resolvedGraph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [
+        { ...decision },
+        { ...depUnknown, status: "resolved" },
+      ],
+      edges: [
+        makeEdge({ fromNodeId: depUnknown.id, toNodeId: decision.id, relationship: "depends_on" }),
+      ],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, resolvedGraph)).toBe(false);
+  });
+
+  // Test 5 — hierarchy (Route A)
+  it("returns true when the decision has an unresolved child unknown via parentId", () => {
+    const childUnknown = makeNode({
+      id: "n_child",
+      label: "Child unknown",
+      kind: "unknown",
+      status: "unknown",
+    });
+    const decision = makeNode({
+      id: "n_decision",
+      label: "Parent Decision",
+      kind: "unknown",
+      status: "unknown",
+      childIds: [childUnknown.id],
+    });
+    childUnknown.parentId = decision.id;
+
+    const graph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision, childUnknown],
+      edges: [],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(true);
+  });
+
+  // Test 6 — weak relationship excluded
+  it("returns false when only supports/measures connects unresolved node to decision or option", () => {
+    const decision = makeNode({
+      id: "n_decision",
+      label: "Decision",
+      kind: "unknown",
+      status: "unknown",
+    });
+    const optA = makeNode({
+      id: "opt_a",
+      label: "Option A",
+      kind: "option",
+      status: "known",
+    });
+    const weakUnknown = makeNode({
+      id: "n_weak",
+      label: "Weakly related unknown",
+      kind: "unknown",
+      status: "unknown",
+    });
+
+    const graph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision, optA, weakUnknown],
+      edges: [
+        makeEdge({ fromNodeId: optA.id, toNodeId: decision.id, relationship: "contained_in" }),
+        makeEdge({ fromNodeId: weakUnknown.id, toNodeId: optA.id, relationship: "supports" }),
+      ],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(false);
+
+    // Also test measures
+    const graphMeasures = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision, optA, weakUnknown],
+      edges: [
+        makeEdge({ fromNodeId: optA.id, toNodeId: decision.id, relationship: "contained_in" }),
+        makeEdge({ fromNodeId: weakUnknown.id, toNodeId: optA.id, relationship: "measures" }),
+      ],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graphMeasures)).toBe(false);
+  });
+
+  // Test 7 — parent decision does not self-count
+  it("returns false when the decision node itself is kind=unknown status=unknown with no subordinate factors", () => {
+    const decision = makeNode({
+      id: "n_decision_self",
+      label: "Decision itself is unknown",
+      kind: "unknown",
+      status: "unknown",
+    });
+
+    const graph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision],
+      edges: [],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(false);
+  });
+
+  // Test 8 — hierarchy child remains unresolved
+  it("returns true when a hierarchy child unknown stays unresolved", () => {
+    const childUnknown = makeNode({
+      id: "n_child_factor",
+      label: "Child factor",
+      kind: "unknown",
+      status: "unknown",
+    });
+    const decision = makeNode({
+      id: "n_parent_dec",
+      label: "Parent decision",
+      kind: "unknown",
+      status: "unknown",
+      childIds: [childUnknown.id],
+    });
+    childUnknown.parentId = decision.id;
+
+    const graph = makeGraph({
+      centralStatement: "hierarchy child remains", currentSummary: "Decision context under test.",
+      nodes: [decision, childUnknown],
+      edges: [],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(true);
+  });
+
+  // Test — status=known excluded (not terminal but also not unresolved)
+  it("returns false when unknown has status=known", () => {
+    const decision = makeNode({ id: "n_dec", label: "D", kind: "unknown", status: "unknown" });
+    const optA = makeNode({ id: "opt_a", label: "O", kind: "option", status: "known" });
+    const knownUnknown = makeNode({ id: "n_known", label: "Known unknown", kind: "unknown", status: "known" });
+
+    const graph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision, optA, knownUnknown],
+      edges: [
+        makeEdge({ fromNodeId: optA.id, toNodeId: decision.id, relationship: "contained_in" }),
+        makeEdge({ fromNodeId: knownUnknown.id, toNodeId: optA.id, relationship: "contained_in" }),
+      ],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(false);
+  });
+
+  // Test — contradicted excluded
+  it("returns false when unknown has status=contradicted", () => {
+    const decision = makeNode({ id: "n_dec", label: "D", kind: "unknown", status: "unknown" });
+    const optA = makeNode({ id: "opt_a", label: "O", kind: "option", status: "known" });
+    const contradictedUnknown = makeNode({ id: "n_contra", label: "Contradicted unknown", kind: "unknown", status: "contradicted" });
+
+    const graph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision, optA, contradictedUnknown],
+      edges: [
+        makeEdge({ fromNodeId: optA.id, toNodeId: decision.id, relationship: "contained_in" }),
+        makeEdge({ fromNodeId: contradictedUnknown.id, toNodeId: optA.id, relationship: "contained_in" }),
+      ],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(false);
+  });
+
+  // Test — non-unknown nodes excluded even if unresolved
+  it("returns false when only option-level unknowns of other kinds are present", () => {
+    const decision = makeNode({ id: "n_dec", label: "D", kind: "unknown", status: "unknown" });
+    const optA = makeNode({ id: "opt_a", label: "O", kind: "option", status: "known" });
+    const obsNode = makeNode({ id: "n_obs", label: "Observation", kind: "observation", status: "supported" });
+
+    const graph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision, optA, obsNode],
+      edges: [
+        makeEdge({ fromNodeId: optA.id, toNodeId: decision.id, relationship: "contained_in" }),
+        makeEdge({ fromNodeId: obsNode.id, toNodeId: optA.id, relationship: "measures" }),
+      ],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(false);
+  });
+
+  // Test 60B.56 sufficiency regression: all factors resolved, decision still unknown
+  it("returns false after customer-signing factor is resolved (60B.56 sufficiency)", () => {
+    const decision = makeNode({ id: "n_decision", label: "Decision", kind: "unknown", status: "unknown" });
+    const optA = makeNode({ id: "opt_a", label: "Option A", kind: "option", status: "known" });
+    const optB = makeNode({ id: "opt_b", label: "Option B", kind: "option", status: "known" });
+    const resolvedFactor = makeNode({ id: "n_factor", label: "Resolved factor", kind: "unknown", status: "resolved" });
+
+    const graph = makeGraph({
+      centralStatement: "60B.56 sufficiency: no unresolved factors remain", currentSummary: "Decision context under test.",
+      nodes: [decision, optA, optB, resolvedFactor],
+      edges: [
+        makeEdge({ fromNodeId: optA.id, toNodeId: decision.id, relationship: "contained_in" }),
+        makeEdge({ fromNodeId: optB.id, toNodeId: decision.id, relationship: "contained_in" }),
+        makeEdge({ fromNodeId: resolvedFactor.id, toNodeId: optA.id, relationship: "contained_in" }),
+      ],
+      activeUnknownNodeId: null,
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(false);
+  });
+
+  // Test — arbitrary connectivity excluded
+  it("returns false when unknown is only connected via non-approved edges to unrelated nodes", () => {
+    const decision = makeNode({ id: "n_dec", label: "D", kind: "unknown", status: "unknown" });
+    const optA = makeNode({ id: "opt_a", label: "O", kind: "option", status: "known" });
+    const farUnknown = makeNode({ id: "n_far", label: "Far unknown", kind: "unknown", status: "unknown" });
+    const bridgeOpt = makeNode({ id: "opt_bridge", label: "Bridge opt", kind: "option", status: "known" });
+
+    const graph = makeGraph({
+      centralStatement: "test", currentSummary: "Decision context under test.",
+      nodes: [decision, optA, farUnknown, bridgeOpt],
+      edges: [
+        makeEdge({ fromNodeId: optA.id, toNodeId: decision.id, relationship: "contained_in" }),
+        makeEdge({ fromNodeId: bridgeOpt.id, toNodeId: decision.id, relationship: "contained_in" }),
+        // farUnknown connected only via 'other' edge — not an approved route
+        makeEdge({ fromNodeId: farUnknown.id, toNodeId: bridgeOpt.id, relationship: "other" }),
+      ],
+    });
+
+    expect(hasRemainingMaterialFactors(decision.id, graph)).toBe(false);
+  });
+});
+