diff --git a/CHANGELOG_NEXT.md b/CHANGELOG_NEXT.md
index 83c7005bfa..06717c2ebe 100644
--- a/CHANGELOG_NEXT.md
+++ b/CHANGELOG_NEXT.md
@@ -24,6 +24,7 @@
 ### :house: (Internal)
 
 * chore: remove checks for unsupported node versions [#4341](https://github.com/open-telemetry/opentelemetry-js/pull/4341) @dyladan
-* refactor(sdk-trace-base): remove `BasicTracerProvider._registeredSpanProcessors` private property. [#5134](https://github.com/open-telemetry/opentelemetry-js/pull/5177) @david-luna
+* refactor(sdk-trace-base): remove `BasicTracerProvider._registeredSpanProcessors` private property. [#5134](https://github.com/open-telemetry/opentelemetry-js/pull/5134) @david-luna
+* refactor(sdk-trace-base): rename `BasicTracerProvider.activeSpanProcessor` private property. [#5211](https://github.com/open-telemetry/opentelemetry-js/pull/5211) @david-luna
 
 ### :bug: (Bug Fix)
diff --git a/experimental/packages/opentelemetry-sdk-node/test/sdk.test.ts b/experimental/packages/opentelemetry-sdk-node/test/sdk.test.ts
index 064584a1f4..c5cf447231 100644
--- a/experimental/packages/opentelemetry-sdk-node/test/sdk.test.ts
+++ b/experimental/packages/opentelemetry-sdk-node/test/sdk.test.ts
@@ -262,7 +262,7 @@ describe('Node SDK', () => {
 
       assert.ok(nodeTracerProvider instanceof NodeTracerProvider);
 
-      const spanProcessor = nodeTracerProvider['activeSpanProcessor'] as any;
+      const spanProcessor = nodeTracerProvider['_activeSpanProcessor'] as any;
 
       assert(
         spanProcessor.constructor.name === 'MultiSpanProcessor',
@@ -1117,7 +1117,7 @@ describe('setup exporter from env', () => {
 
     assert(tracerProvider instanceof NodeTracerProvider);
 
-    const activeSpanProcessor = tracerProvider['activeSpanProcessor'];
+    const activeSpanProcessor = tracerProvider['_activeSpanProcessor'];
 
     assert(activeSpanProcessor.constructor.name === 'MultiSpanProcessor');
 
diff --git a/packages/opentelemetry-sdk-trace-base/src/BasicTracerProvider.ts b/packages/opentelemetry-sdk-trace-base/src/BasicTracerProvider.ts
index 453d96186d..b99d6a664f 100644
--- a/packages/opentelemetry-sdk-trace-base/src/BasicTracerProvider.ts
+++ b/packages/opentelemetry-sdk-trace-base/src/BasicTracerProvider.ts
@@ -69,8 +69,7 @@ export class BasicTracerProvider implements TracerProvider {
   private readonly _config: TracerConfig;
   private readonly _tracers: Map<string, Tracer> = new Map();
   private readonly _resource: IResource;
-
-  private activeSpanProcessor: MultiSpanProcessor;
+  private readonly _activeSpanProcessor: MultiSpanProcessor;
 
   constructor(config: TracerConfig = {}) {
     const mergedConfig = merge(
@@ -101,7 +100,7 @@ export class BasicTracerProvider implements TracerProvider {
       );
     }
 
-    this.activeSpanProcessor = new MultiSpanProcessor(spanProcessors);
+    this._activeSpanProcessor = new MultiSpanProcessor(spanProcessors);
   }
 
   getTracer(
@@ -117,7 +116,7 @@ export class BasicTracerProvider implements TracerProvider {
           { name, version, schemaUrl: options?.schemaUrl },
           this._config,
           this._resource,
-          this.activeSpanProcessor
+          this._activeSpanProcessor
         )
       );
     }
@@ -150,7 +149,7 @@ export class BasicTracerProvider implements TracerProvider {
 
   forceFlush(): Promise<void> {
     const timeout = this._config.forceFlushTimeoutMillis;
-    const promises = this.activeSpanProcessor['_spanProcessors'].map(
+    const promises = this._activeSpanProcessor['_spanProcessors'].map(
       (spanProcessor: SpanProcessor) => {
         return new Promise(resolve => {
           let state: ForceFlushState;
@@ -198,7 +197,7 @@ export class BasicTracerProvider implements TracerProvider {
   }
 
   shutdown(): Promise<void> {
-    return this.activeSpanProcessor.shutdown();
+    return this._activeSpanProcessor.shutdown();
   }
 
   /**
diff --git a/packages/opentelemetry-sdk-trace-base/test/common/BasicTracerProvider.test.ts b/packages/opentelemetry-sdk-trace-base/test/common/BasicTracerProvider.test.ts
index 4d1a3d399f..62395128f9 100644
--- a/packages/opentelemetry-sdk-trace-base/test/common/BasicTracerProvider.test.ts
+++ b/packages/opentelemetry-sdk-trace-base/test/common/BasicTracerProvider.test.ts
@@ -92,12 +92,12 @@ describe('BasicTracerProvider', () => {
 
       it('should use noop span processor by default', () => {
         const tracer = new BasicTracerProvider();
-        assert.ok(tracer['activeSpanProcessor'] instanceof MultiSpanProcessor);
+        assert.ok(tracer['_activeSpanProcessor'] instanceof MultiSpanProcessor);
         assert.ok(
-          tracer['activeSpanProcessor']['_spanProcessors'].length === 1
+          tracer['_activeSpanProcessor']['_spanProcessors'].length === 1
         );
         assert.ok(
-          tracer['activeSpanProcessor']['_spanProcessors'][0] instanceof
+          tracer['_activeSpanProcessor']['_spanProcessors'][0] instanceof
             NoopSpanProcessor
         );
       });
@@ -105,12 +105,12 @@ describe('BasicTracerProvider', () => {
         const errorStub = sinon.spy(diag, 'error');
         const tracer = new BasicTracerProvider();
 
-        assert.ok(tracer['activeSpanProcessor'] instanceof MultiSpanProcessor);
+        assert.ok(tracer['_activeSpanProcessor'] instanceof MultiSpanProcessor);
         assert.ok(
-          tracer['activeSpanProcessor']['_spanProcessors'].length === 1
+          tracer['_activeSpanProcessor']['_spanProcessors'].length === 1
         );
         assert.ok(
-          tracer['activeSpanProcessor']['_spanProcessors'][0] instanceof
+          tracer['_activeSpanProcessor']['_spanProcessors'][0] instanceof
             NoopSpanProcessor
         );
         sinon.assert.notCalled(errorStub);
@@ -123,12 +123,12 @@ describe('BasicTracerProvider', () => {
         const errorStub = sinon.spy(diag, 'error');
         const tracer = new BasicTracerProvider();
 
-        assert.ok(tracer['activeSpanProcessor'] instanceof MultiSpanProcessor);
+        assert.ok(tracer['_activeSpanProcessor'] instanceof MultiSpanProcessor);
         assert.ok(
-          tracer['activeSpanProcessor']['_spanProcessors'].length === 1
+          tracer['_activeSpanProcessor']['_spanProcessors'].length === 1
         );
         assert.ok(
-          tracer['activeSpanProcessor']['_spanProcessors'][0] instanceof
+          tracer['_activeSpanProcessor']['_spanProcessors'][0] instanceof
             NoopSpanProcessor
         );
         sinon.assert.calledWith(
@@ -147,16 +147,16 @@ describe('BasicTracerProvider', () => {
           spanProcessors: [spanProcessor],
         });
 
-        assert.ok(tracer['activeSpanProcessor'] instanceof MultiSpanProcessor);
+        assert.ok(tracer['_activeSpanProcessor'] instanceof MultiSpanProcessor);
         assert.ok(
-          tracer['activeSpanProcessor']['_spanProcessors'].length === 1
+          tracer['_activeSpanProcessor']['_spanProcessors'].length === 1
         );
         assert.ok(
-          tracer['activeSpanProcessor']['_spanProcessors'][0] instanceof
+          tracer['_activeSpanProcessor']['_spanProcessors'][0] instanceof
             SimpleSpanProcessor
         );
         assert.ok(
-          tracer['activeSpanProcessor']['_spanProcessors'][0][
+          tracer['_activeSpanProcessor']['_spanProcessors'][0][
             '_exporter'
           ] instanceof ConsoleSpanExporter
         );
@@ -466,16 +466,16 @@ describe('BasicTracerProvider', () => {
       /* BasicTracerProvider has no exporters by default, so skipping testing the exporter getter */
       provider.register();
 
-      assert.ok(provider['activeSpanProcessor'] instanceof MultiSpanProcessor);
+      assert.ok(provider['_activeSpanProcessor'] instanceof MultiSpanProcessor);
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'].length === 1
+        provider['_activeSpanProcessor']['_spanProcessors'].length === 1
       );
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'][0] instanceof
+        provider['_activeSpanProcessor']['_spanProcessors'][0] instanceof
           BatchSpanProcessor
       );
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'][0][
+        provider['_activeSpanProcessor']['_spanProcessors'][0][
           '_exporter'
         ] instanceof DummyExporter
       );
@@ -521,16 +521,16 @@ describe('BasicTracerProvider', () => {
       const provider = new CustomTracerProvider({});
       provider.register();
 
-      assert.ok(provider['activeSpanProcessor'] instanceof MultiSpanProcessor);
+      assert.ok(provider['_activeSpanProcessor'] instanceof MultiSpanProcessor);
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'].length === 1
+        provider['_activeSpanProcessor']['_spanProcessors'].length === 1
       );
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'][0] instanceof
+        provider['_activeSpanProcessor']['_spanProcessors'][0] instanceof
           BatchSpanProcessor
       );
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'][0][
+        provider['_activeSpanProcessor']['_spanProcessors'][0][
           '_exporter'
         ] instanceof DummyExporter
       );
@@ -635,17 +635,17 @@ describe('BasicTracerProvider', () => {
         provider.register();
 
         assert.ok(
-          provider['activeSpanProcessor'] instanceof MultiSpanProcessor
+          provider['_activeSpanProcessor'] instanceof MultiSpanProcessor
         );
         assert.ok(
-          provider['activeSpanProcessor']['_spanProcessors'].length === 1
+          provider['_activeSpanProcessor']['_spanProcessors'].length === 1
         );
         assert.ok(
-          provider['activeSpanProcessor']['_spanProcessors'][0] instanceof
+          provider['_activeSpanProcessor']['_spanProcessors'][0] instanceof
             BatchSpanProcessor
         );
         assert.ok(
-          provider['activeSpanProcessor']['_spanProcessors'][0][
+          provider['_activeSpanProcessor']['_spanProcessors'][0][
             '_exporter'
           ] instanceof InMemorySpanExporter
         );
@@ -958,7 +958,7 @@ describe('BasicTracerProvider', () => {
     it('should trigger shutdown when manually invoked', () => {
       const tracerProvider = new BasicTracerProvider();
       const shutdownStub = sinon.stub(
-        tracerProvider['activeSpanProcessor'],
+        tracerProvider['_activeSpanProcessor'],
         'shutdown'
       );
       tracerProvider.shutdown();
diff --git a/packages/opentelemetry-sdk-trace-base/test/common/MultiSpanProcessor.test.ts b/packages/opentelemetry-sdk-trace-base/test/common/MultiSpanProcessor.test.ts
index ddafa8b913..34292ed899 100644
--- a/packages/opentelemetry-sdk-trace-base/test/common/MultiSpanProcessor.test.ts
+++ b/packages/opentelemetry-sdk-trace-base/test/common/MultiSpanProcessor.test.ts
@@ -63,7 +63,7 @@ describe('MultiSpanProcessor', () => {
     assert.strictEqual(processor1.spans.length, 0);
     span.end();
     assert.strictEqual(processor1.spans.length, 1);
-    tracerProvider['activeSpanProcessor'].shutdown();
+    tracerProvider['_activeSpanProcessor'].shutdown();
   });
 
   it('should handle two span processor', async () => {
diff --git a/packages/opentelemetry-sdk-trace-base/test/common/Tracer.test.ts b/packages/opentelemetry-sdk-trace-base/test/common/Tracer.test.ts
index 3912e9ae6f..41e374e15c 100644
--- a/packages/opentelemetry-sdk-trace-base/test/common/Tracer.test.ts
+++ b/packages/opentelemetry-sdk-trace-base/test/common/Tracer.test.ts
@@ -115,7 +115,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       {},
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
     assert.ok(tracer instanceof Tracer);
   });
@@ -125,7 +125,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       {},
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
     assert.strictEqual(
       tracer['_sampler'].toString(),
@@ -138,7 +138,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       { sampler: new AlwaysOffSampler() },
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
     const span = tracer.startSpan('span1');
     assert.ok(!span.isRecording());
@@ -150,7 +150,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       { sampler: new AlwaysOnSampler() },
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
     const span = tracer.startSpan('span2');
     assert.ok(span.isRecording());
@@ -162,7 +162,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       { sampler: new TestSampler() },
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
     const span = tracer.startSpan('span3');
     assert.strictEqual((span as Span).attributes.testAttribute, 'foobar');
@@ -175,7 +175,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       { sampler: new TestSampler(traceState) },
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
     const span = tracer.startSpan('stateSpan');
     assert.strictEqual(span.spanContext().traceState, traceState);
@@ -186,7 +186,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       {},
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
 
     const lib: InstrumentationLibrary = tracer.instrumentationLibrary;
@@ -203,7 +203,7 @@ describe('Tracer', () => {
         { name: 'default', version: '0.0.1' },
         { sampler: new TestSampler() },
         tracerProvider['_resource'],
-        tracerProvider['activeSpanProcessor']
+        tracerProvider['_activeSpanProcessor']
       );
 
       const span = tracer.startSpan('span3', undefined, context);
@@ -227,7 +227,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       {},
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
     const span = tracer.startSpan(
       'aSpan',
@@ -249,7 +249,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       {},
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
     const span = tracer.startSpan(
       'aSpan',
@@ -279,7 +279,7 @@ describe('Tracer', () => {
       { name: 'default' },
       { sampler },
       tp['_resource'],
-      tp['activeSpanProcessor']
+      tp['_activeSpanProcessor']
     );
     const span = tracer.startSpan('a', {}, context) as Span;
     assert.strictEqual(span.parentSpanId, parent.spanId);
@@ -315,7 +315,7 @@ describe('Tracer', () => {
       { name: 'default' },
       { sampler },
       tp['_resource'],
-      tp['activeSpanProcessor']
+      tp['_activeSpanProcessor']
     );
     const span = tracer.startSpan('a', { root: true }, context) as Span;
     assert.strictEqual(span.parentSpanId, undefined);
@@ -334,7 +334,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       {},
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
     const span = tracer.startSpan('my-span');
     const context = span.spanContext();
@@ -349,7 +349,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       {},
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
     const span = tracer.startSpan('my-span');
     const context = span.spanContext();
@@ -364,7 +364,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       {},
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
     const span = tracer.startSpan('my-span');
     const context = span.spanContext();
@@ -377,7 +377,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       { sampler: new TestSampler() },
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
 
     const spy = sinon.spy(tracer, 'startSpan');
@@ -401,7 +401,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       { sampler: new TestSampler() },
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
 
     const spy = sinon.spy(tracer, 'startSpan');
@@ -429,7 +429,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       { sampler: new TestSampler() },
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
 
     const ctxKey = createContextKey('foo');
@@ -465,7 +465,7 @@ describe('Tracer', () => {
       { name: 'default', version: '0.0.1' },
       { sampler: new TestSampler() },
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
 
     const attributes = {
diff --git a/packages/opentelemetry-sdk-trace-base/test/common/export/TestTracingSpanExporter.ts b/packages/opentelemetry-sdk-trace-base/test/common/export/TestTracingSpanExporter.ts
index da79bc8ea1..3153b1f48c 100644
--- a/packages/opentelemetry-sdk-trace-base/test/common/export/TestTracingSpanExporter.ts
+++ b/packages/opentelemetry-sdk-trace-base/test/common/export/TestTracingSpanExporter.ts
@@ -56,7 +56,7 @@ export class TestTracingSpanExporter extends InMemorySpanExporter {
       { name: 'default', version: '0.0.1' },
       { sampler: new AlwaysOnSampler() },
       tracerProvider['_resource'],
-      tracerProvider['activeSpanProcessor']
+      tracerProvider['_activeSpanProcessor']
     );
   }
 
diff --git a/packages/opentelemetry-sdk-trace-node/test/NodeTracerProvider.test.ts b/packages/opentelemetry-sdk-trace-node/test/NodeTracerProvider.test.ts
index 2bf1e769f8..f9017f1534 100644
--- a/packages/opentelemetry-sdk-trace-node/test/NodeTracerProvider.test.ts
+++ b/packages/opentelemetry-sdk-trace-node/test/NodeTracerProvider.test.ts
@@ -304,18 +304,18 @@ describe('NodeTracerProvider', () => {
       provider.register();
 
       assert.ok(
-        provider['activeSpanProcessor'].constructor.name ===
+        provider['_activeSpanProcessor'].constructor.name ===
           'MultiSpanProcessor'
       );
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'].length === 1
+        provider['_activeSpanProcessor']['_spanProcessors'].length === 1
       );
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'][0] instanceof
+        provider['_activeSpanProcessor']['_spanProcessors'][0] instanceof
           BatchSpanProcessor
       );
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'][0][
+        provider['_activeSpanProcessor']['_spanProcessors'][0][
           '_exporter'
         ] instanceof DummyExporter
       );
@@ -361,18 +361,18 @@ describe('NodeTracerProvider', () => {
       provider.register();
 
       assert.ok(
-        provider['activeSpanProcessor'].constructor.name ===
+        provider['_activeSpanProcessor'].constructor.name ===
           'MultiSpanProcessor'
       );
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'].length === 1
+        provider['_activeSpanProcessor']['_spanProcessors'].length === 1
       );
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'][0] instanceof
+        provider['_activeSpanProcessor']['_spanProcessors'][0] instanceof
           BatchSpanProcessor
       );
       assert.ok(
-        provider['activeSpanProcessor']['_spanProcessors'][0][
+        provider['_activeSpanProcessor']['_spanProcessors'][0][
           '_exporter'
         ] instanceof DummyExporter
       );