diff --git a/src/index.ts b/src/index.ts
index 7a6aa15..46ed8a5 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -16,7 +16,9 @@ import {
   listActiveClientScenarios,
   listPendingClientScenarios,
   listAuthScenarios,
-  listMetadataScenarios
+  listMetadataScenarios,
+  listCoreScenarios,
+  listExtensionScenarios
 } from './scenarios';
 import { ConformanceCheck } from './types';
 import { ClientOptionsSchema, ServerOptionsSchema } from './schemas';
@@ -65,6 +67,8 @@ program
 
         const suites: Record<string, () => string[]> = {
           all: listScenarios,
+          core: listCoreScenarios,
+          extensions: listExtensionScenarios,
           auth: listAuthScenarios,
           metadata: listMetadataScenarios,
           'sep-835': () =>
@@ -177,7 +181,9 @@ program
         console.error('Either --scenario or --suite is required');
         console.error('\nAvailable client scenarios:');
         listScenarios().forEach((s) => console.error(`  - ${s}`));
-        console.error('\nAvailable suites: all, auth, metadata, sep-835');
+        console.error(
+          '\nAvailable suites: all, core, extensions, auth, metadata, sep-835'
+        );
         process.exit(1);
       }
 
@@ -296,13 +302,14 @@ program
 
         if (suite === 'all') {
           scenarios = listClientScenarios();
-        } else if (suite === 'active') {
+        } else if (suite === 'active' || suite === 'core') {
+          // 'core' is an alias for 'active' - tier 1 requirements
           scenarios = listActiveClientScenarios();
         } else if (suite === 'pending') {
           scenarios = listPendingClientScenarios();
         } else {
           console.error(`Unknown suite: ${suite}`);
-          console.error('Available suites: active, all, pending');
+          console.error('Available suites: active, all, core, pending');
           process.exit(1);
         }
 
diff --git a/src/scenarios/client/auth/index.ts b/src/scenarios/client/auth/index.ts
index 6a3ad1c..805781a 100644
--- a/src/scenarios/client/auth/index.ts
+++ b/src/scenarios/client/auth/index.ts
@@ -22,6 +22,7 @@ import {
   ClientCredentialsBasicScenario
 } from './client-credentials';
 
+// Auth scenarios (required for tier 1)
 export const authScenariosList: Scenario[] = [
   ...metadataScenarios,
   new AuthBasicCIMDScenario(),
@@ -34,7 +35,11 @@ export const authScenariosList: Scenario[] = [
   new ScopeRetryLimitScenario(),
   new ClientSecretBasicAuthScenario(),
   new ClientSecretPostAuthScenario(),
-  new PublicClientAuthScenario(),
+  new PublicClientAuthScenario()
+];
+
+// Extension scenarios (optional for tier 1 - protocol extensions)
+export const extensionScenariosList: Scenario[] = [
   new ClientCredentialsJwtScenario(),
   new ClientCredentialsBasicScenario()
 ];
diff --git a/src/scenarios/index.ts b/src/scenarios/index.ts
index 6dc8070..0c3e4aa 100644
--- a/src/scenarios/index.ts
+++ b/src/scenarios/index.ts
@@ -53,24 +53,16 @@ import {
 
 import { DNSRebindingProtectionScenario } from './server/dns-rebinding';
 
-import { authScenariosList } from './client/auth/index';
+import { authScenariosList, extensionScenariosList } from './client/auth/index';
 import { listMetadataScenarios } from './client/auth/discovery-metadata';
 
 // Pending client scenarios (not yet fully tested/implemented)
 const pendingClientScenariosList: ClientScenario[] = [
-  // Elicitation scenarios (SEP-1330)
-  new ElicitationEnumsScenario(),
-
   // JSON Schema 2020-12 (SEP-1613)
   // This test is pending until the SDK includes PR #1135 which preserves
   // $schema, $defs, and additionalProperties fields in tool schemas.
   new JsonSchema2020_12Scenario(),
 
-  // On hold until elicitation schema types are fixed
-  // https://github.com/modelcontextprotocol/modelcontextprotocol/pull/1863
-  new ToolsCallElicitationScenario(),
-  new ElicitationDefaultsScenario(),
-
   // On hold until server-side SSE improvements are made
   // https://github.com/modelcontextprotocol/typescript-sdk/pull/1129
   new ServerSSEPollingScenario()
@@ -145,8 +137,18 @@ export const clientScenarios = new Map<string, ClientScenario>(
   allClientScenariosList.map((scenario) => [scenario.name, scenario])
 );
 
-// Scenario scenarios
+// All client test scenarios (core + extensions)
 const scenariosList: Scenario[] = [
+  new InitializeScenario(),
+  new ToolsCallScenario(),
+  new ElicitationClientDefaultsScenario(),
+  new SSERetryScenario(),
+  ...authScenariosList,
+  ...extensionScenariosList
+];
+
+// Core scenarios (tier 1 requirements)
+const coreScenariosList: Scenario[] = [
   new InitializeScenario(),
   new ToolsCallScenario(),
   new ElicitationClientDefaultsScenario(),
@@ -191,4 +193,12 @@ export function listAuthScenarios(): string[] {
   return authScenariosList.map((scenario) => scenario.name);
 }
 
+export function listCoreScenarios(): string[] {
+  return coreScenariosList.map((scenario) => scenario.name);
+}
+
+export function listExtensionScenarios(): string[] {
+  return extensionScenariosList.map((scenario) => scenario.name);
+}
+
 export { listMetadataScenarios };