diff --git a/src/cli/analyzeSession.ts b/src/cli/analyzeSession.ts
index 47189a30..eb40a615 100644
--- a/src/cli/analyzeSession.ts
+++ b/src/cli/analyzeSession.ts
@@ -43,14 +43,6 @@ const PRICE_PER_MTOK: Record<string, [number, number, number, number]> = {
   haiku: [1, 5, 0.1, 1.25],
 };
 
-// ponytail: local stopgap for short ids (claude-sonnet-5) while upstream PR #235 is unmerged
-export function priceFamily(model: string): string | null {
-  const info = parseModelString(model);
-  if (info) return info.family;
-  const m = /claude-(opus|sonnet|haiku)/.exec(model.toLowerCase());
-  return m ? m[1] : null;
-}
-
 export type BillingScheme = 'anthropic-style' | 'router-style' | 'no-cache' | 'mixed';
 
 // anthropic-style billing has cache_write > 0 on rounds; routers typically report
@@ -157,7 +149,7 @@ function thinkingTokensOf(msg: ParsedMessage): number {
 
 // cost of one round at the built-in claude price table; null = unpriced model
 export function roundCostUsd(r: RoundRow): number | null {
-  const price = PRICE_PER_MTOK[priceFamily(r.model) ?? ''];
+  const price = PRICE_PER_MTOK[parseModelString(r.model)?.family ?? ''];
   if (!price) return null;
   return (
     (r.inputTokens * price[0] +
diff --git a/src/shared/utils/modelParser.ts b/src/shared/utils/modelParser.ts
index 8d9fbf37..a3011702 100644
--- a/src/shared/utils/modelParser.ts
+++ b/src/shared/utils/modelParser.ts
@@ -28,6 +28,7 @@ const KNOWN_FAMILIES: KnownModelFamily[] = ['sonnet', 'opus', 'haiku'];
  *
  * Supported formats:
  * - New format: claude-{family}-{major}-{minor}-{date} (e.g., "claude-sonnet-4-5-20250929")
+ * - New format short: claude-{family}-{major} (e.g., "claude-sonnet-5")
  * - Old format: claude-{major}-{family}-{date} (e.g., "claude-3-opus-20240229")
  * - Old format with minor: claude-{major}-{minor}-{family}-{date} (e.g., "claude-3-5-sonnet-20241022")
  */
@@ -87,14 +88,12 @@ export function parseModelString(model: string | undefined): ModelInfo | null {
 
   // Determine format based on family position
   if (familyIndex === 1) {
-    // New format: claude-{family}-{major}-{minor}-{date}
+    // New format: claude-{family}-{major}[-{minor}][-{date}]
     // e.g., claude-sonnet-4-5-20250929 -> ["claude", "sonnet", "4", "5", "20250929"]
-    if (parts.length < 4) {
-      return null;
-    }
-
+    // e.g., claude-sonnet-5 -> ["claude", "sonnet", "5"]
     majorVersion = parseInt(parts[2], 10);
-    if (isNaN(majorVersion)) {
+    // 8 digits in major position is a misplaced date (claude-sonnet-20250929), not a version
+    if (isNaN(majorVersion) || /^\d{8}$/.test(parts[2])) {
       return null;
     }
 
diff --git a/test/main/cli/analyzeSession.test.ts b/test/main/cli/analyzeSession.test.ts
index 47684f6b..0c330eff 100644
--- a/test/main/cli/analyzeSession.test.ts
+++ b/test/main/cli/analyzeSession.test.ts
@@ -17,7 +17,6 @@ import {
   filterLedgerByDate,
   normalizeCallKey,
   parseArgs,
-  priceFamily,
 } from '../../../src/cli/analyzeSession';
 import { mapWithConcurrency, scanSessionFile } from '../../../src/cli/sessionInventory';
 import { estimateTokens } from '../../../src/shared/utils/tokenFormatting';
@@ -327,13 +326,7 @@ describe('mapWithConcurrency', () => {
   });
 });
 
-describe('priceFamily and billing scheme', () => {
-  it('extracts claude family from short ids without date', () => {
-    expect(priceFamily('claude-sonnet-5')).toBe('sonnet');
-    expect(priceFamily('claude-sonnet-5-20250929')).toBe('sonnet');
-    expect(priceFamily('glm-5.3-flash')).toBeNull();
-  });
-
+describe('billing scheme', () => {
   it('detects billing scheme from round signatures', () => {
     const w = { cacheReadTokens: 0, cacheCreationTokens: 100 };
     const r = { cacheReadTokens: 500, cacheCreationTokens: 0 };
diff --git a/test/shared/utils/modelParser.test.ts b/test/shared/utils/modelParser.test.ts
index fae2532c..d8ca2fa4 100644
--- a/test/shared/utils/modelParser.test.ts
+++ b/test/shared/utils/modelParser.test.ts
@@ -102,6 +102,24 @@ describe('modelParser', () => {
       });
     });
 
+    it('should parse short format without minor or date: claude-sonnet-5', () => {
+      const result = parseModelString('claude-sonnet-5');
+      expect(result).toEqual({
+        name: 'sonnet5',
+        family: 'sonnet',
+        majorVersion: 5,
+        minorVersion: null,
+      });
+    });
+
+    it('should return null for invalid short format with non-numeric version', () => {
+      expect(parseModelString('claude-sonnet-x')).toBeNull();
+    });
+
+    it('should return null for date-shaped major version: claude-sonnet-20250929', () => {
+      expect(parseModelString('claude-sonnet-20250929')).toBeNull();
+    });
+
     it('should return null for invalid format with only two parts', () => {
       expect(parseModelString('claude-sonnet')).toBeNull();
     });