diff --git a/src/web-server/model-pricing.ts b/src/web-server/model-pricing.ts
index 4513d36c..dc05d2a6 100644
--- a/src/web-server/model-pricing.ts
+++ b/src/web-server/model-pricing.ts
@@ -151,6 +151,19 @@ const PRICING_REGISTRY: Record<string, ModelPricing> = {
     cacheCreationPerMillion: 3.75,
     cacheReadPerMillion: 0.3,
   },
+  // Claude 4.6 Sonnet ($3/$15)
+  'claude-sonnet-4-6': {
+    inputPerMillion: 3.0,
+    outputPerMillion: 15.0,
+    cacheCreationPerMillion: 3.75,
+    cacheReadPerMillion: 0.3,
+  },
+  'claude-sonnet-4-6-thinking': {
+    inputPerMillion: 3.0,
+    outputPerMillion: 15.0,
+    cacheCreationPerMillion: 3.75,
+    cacheReadPerMillion: 0.3,
+  },
   // Claude 4 Opus ($15/$75)
   'claude-4-opus-20250514': {
     inputPerMillion: 15.0,
@@ -202,6 +215,19 @@ const PRICING_REGISTRY: Record<string, ModelPricing> = {
     cacheCreationPerMillion: 6.25,
     cacheReadPerMillion: 0.5,
   },
+  // Claude 4.6 Opus ($5/$25)
+  'claude-opus-4-6': {
+    inputPerMillion: 5.0,
+    outputPerMillion: 25.0,
+    cacheCreationPerMillion: 6.25,
+    cacheReadPerMillion: 0.5,
+  },
+  'claude-opus-4-6-thinking': {
+    inputPerMillion: 5.0,
+    outputPerMillion: 25.0,
+    cacheCreationPerMillion: 6.25,
+    cacheReadPerMillion: 0.5,
+  },
 
   // ---------------------------------------------------------------------------
   // OpenAI Models - Source: better-ccusage
@@ -708,7 +734,7 @@ const UNKNOWN_MODEL_PRICING: ModelPricing = {
 
 /**
  * Normalize model name for matching
- * Handles variations like provider prefixes and case differences
+ * Handles variations like provider prefixes, case differences, and date suffixes
  */
 function normalizeModelName(model: string): string {
   // Remove provider prefixes (e.g., "anthropic/claude-..." -> "claude-...")
@@ -719,6 +745,14 @@ function normalizeModelName(model: string): string {
   return normalized;
 }
 
+/**
+ * Strip trailing date suffix from model name (e.g., "-20260101")
+ * Only strips 8-digit YYYYMMDD suffixes at the end of the string.
+ */
+function stripDateSuffix(model: string): string {
+  return model.replace(/-\d{8}$/, '');
+}
+
 const NORMALIZED_PRICING_REGISTRY: Record<string, ModelPricing> = Object.entries(
   PRICING_REGISTRY
 ).reduce<Record<string, ModelPricing>>((acc, [key, pricing]) => {
@@ -730,7 +764,22 @@ function getLookupCandidates(model: string): string[] {
   const normalized = normalizeModelName(model);
   const baseModel = normalized.split(':')[0];
 
-  return baseModel === normalized ? [normalized] : [normalized, baseModel];
+  const candidates: string[] = [normalized];
+  if (baseModel !== normalized) {
+    candidates.push(baseModel);
+  }
+
+  // Add date-stripped variants (e.g., "claude-opus-4-6-20260101" -> "claude-opus-4-6")
+  const stripped = stripDateSuffix(normalized);
+  if (stripped !== normalized && !candidates.includes(stripped)) {
+    candidates.push(stripped);
+  }
+  const baseStripped = stripDateSuffix(baseModel);
+  if (baseStripped !== baseModel && !candidates.includes(baseStripped)) {
+    candidates.push(baseStripped);
+  }
+
+  return candidates;
 }
 
 function getDirectOrAliasPricing(model: string): ModelPricing | undefined {
diff --git a/src/web-server/usage/disk-cache.ts b/src/web-server/usage/disk-cache.ts
index 523169c9..c97d1632 100644
--- a/src/web-server/usage/disk-cache.ts
+++ b/src/web-server/usage/disk-cache.ts
@@ -36,7 +36,8 @@ export interface UsageDiskCache {
 
 // Current cache version - increment to invalidate old caches
 // v3: Added hourly data to cache
-const CACHE_VERSION = 3;
+// v4: Pricing fix for Claude 4.6 models (invalidate stale costs)
+const CACHE_VERSION = 4;
 
 /**
  * Ensure ~/.ccs/cache directory exists
diff --git a/tests/unit/model-pricing.test.ts b/tests/unit/model-pricing.test.ts
index 30efdc59..0317b995 100644
--- a/tests/unit/model-pricing.test.ts
+++ b/tests/unit/model-pricing.test.ts
@@ -84,6 +84,42 @@ describe('model-pricing', () => {
       expect(opus.inputPerMillion).toBeGreaterThan(sonnet.inputPerMillion);
       expect(sonnet.inputPerMillion).toBeGreaterThan(haiku.inputPerMillion);
     });
+
+    it('should return correct pricing for Claude Opus 4.6 (not 3x Opus 4 rate)', () => {
+      const opus46 = getModelPricing('claude-opus-4-6');
+      expect(opus46.inputPerMillion).toBe(5.0);
+      expect(opus46.outputPerMillion).toBe(25.0);
+    });
+
+    it('should return correct pricing for Claude Opus 4.6 thinking variant', () => {
+      const opus46t = getModelPricing('claude-opus-4-6-thinking');
+      expect(opus46t.inputPerMillion).toBe(5.0);
+      expect(opus46t.outputPerMillion).toBe(25.0);
+    });
+
+    it('should return correct pricing for Claude Sonnet 4.6', () => {
+      const sonnet46 = getModelPricing('claude-sonnet-4-6');
+      expect(sonnet46.inputPerMillion).toBe(3.0);
+      expect(sonnet46.outputPerMillion).toBe(15.0);
+    });
+
+    it('should match date-stamped Claude Opus 4.6 to correct pricing', () => {
+      const opus46dated = getModelPricing('claude-opus-4-6-20260101');
+      expect(opus46dated.inputPerMillion).toBe(5.0);
+      expect(opus46dated.outputPerMillion).toBe(25.0);
+    });
+
+    it('should match date-stamped Claude Sonnet 4.6 to correct pricing', () => {
+      const sonnet46dated = getModelPricing('claude-sonnet-4-6-20260115');
+      expect(sonnet46dated.inputPerMillion).toBe(3.0);
+      expect(sonnet46dated.outputPerMillion).toBe(15.0);
+    });
+
+    it('should match provider-prefixed date-stamped model to correct pricing', () => {
+      const opus46 = getModelPricing('anthropic/claude-opus-4-6-20260101');
+      expect(opus46.inputPerMillion).toBe(5.0);
+      expect(opus46.outputPerMillion).toBe(25.0);
+    });
   });
 
   describe('calculateCost', () => {