diff --git a/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/DataflowBatchWorkerHarness.java b/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/DataflowBatchWorkerHarness.java
index 51127c2dc2fa4..a1c93cdc57821 100644
--- a/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/DataflowBatchWorkerHarness.java
+++ b/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/DataflowBatchWorkerHarness.java
@@ -32,6 +32,7 @@
 import org.apache.beam.sdk.util.BackOffUtils;
 import org.apache.beam.sdk.util.FluentBackoff;
 import org.apache.beam.sdk.util.Sleeper;
+import org.apache.beam.sdk.util.construction.CoderTranslation;
 import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.annotations.VisibleForTesting;
 import org.joda.time.Duration;
 import org.slf4j.Logger;
@@ -70,6 +71,8 @@ public static void main(String[] args) throws Exception {
         "%s cannot be main() class with beam_fn_api enabled",
         DataflowBatchWorkerHarness.class.getSimpleName());
 
+    CoderTranslation.verifyModelCodersRegistered();
+
     JvmInitializers.runBeforeProcessing(pipelineOptions);
     batchHarness.run();
   }
diff --git a/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/StreamingDataflowWorker.java b/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/StreamingDataflowWorker.java
index 9f822f80a3bdc..82a9ff15b6b89 100644
--- a/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/StreamingDataflowWorker.java
+++ b/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/StreamingDataflowWorker.java
@@ -131,6 +131,7 @@
 import org.apache.beam.sdk.util.FluentBackoff;
 import org.apache.beam.sdk.util.Sleeper;
 import org.apache.beam.sdk.util.WindowedValue.WindowedValueCoder;
+import org.apache.beam.sdk.util.construction.CoderTranslation;
 import org.apache.beam.vendor.grpc.v1p60p1.com.google.protobuf.ByteString;
 import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.annotations.VisibleForTesting;
 import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Preconditions;
@@ -601,6 +602,8 @@ public static void main(String[] args) throws Exception {
         "%s cannot be main() class with beam_fn_api enabled",
         StreamingDataflowWorker.class.getSimpleName());
 
+    CoderTranslation.verifyModelCodersRegistered();
+
     LOG.debug("Creating StreamingDataflowWorker from options: {}", options);
     StreamingDataflowWorker worker = StreamingDataflowWorker.fromOptions(options);
 
diff --git a/sdks/java/core/src/main/java/org/apache/beam/sdk/Pipeline.java b/sdks/java/core/src/main/java/org/apache/beam/sdk/Pipeline.java
index 9bace292d6ad5..d3b58dd26bd24 100644
--- a/sdks/java/core/src/main/java/org/apache/beam/sdk/Pipeline.java
+++ b/sdks/java/core/src/main/java/org/apache/beam/sdk/Pipeline.java
@@ -49,6 +49,7 @@
 import org.apache.beam.sdk.transforms.errorhandling.ErrorHandler.BadRecordErrorHandler;
 import org.apache.beam.sdk.transforms.resourcehints.ResourceHints;
 import org.apache.beam.sdk.util.UserCodeException;
+import org.apache.beam.sdk.util.construction.CoderTranslation;
 import org.apache.beam.sdk.values.PBegin;
 import org.apache.beam.sdk.values.PCollection;
 import org.apache.beam.sdk.values.PInput;
@@ -524,6 +525,7 @@ public static <InputT extends PInput, OutputT extends POutput> OutputT applyTran
   private final List<ErrorHandler<?, ?>> errorHandlers = new ArrayList<>();
 
   private Pipeline(TransformHierarchy transforms, PipelineOptions options) {
+    CoderTranslation.verifyModelCodersRegistered();
     this.transforms = transforms;
     this.defaultOptions = options;
   }
diff --git a/sdks/java/core/src/main/java/org/apache/beam/sdk/util/construction/CoderTranslation.java b/sdks/java/core/src/main/java/org/apache/beam/sdk/util/construction/CoderTranslation.java
index 5a0d8c3cae259..f7250a0d17972 100644
--- a/sdks/java/core/src/main/java/org/apache/beam/sdk/util/construction/CoderTranslation.java
+++ b/sdks/java/core/src/main/java/org/apache/beam/sdk/util/construction/CoderTranslation.java
@@ -201,4 +201,20 @@ private static Coder<?> fromCustomCoder(RunnerApi.Coder protoCoder) throws IOExc
         SerializableUtils.deserializeFromByteArray(
             protoCoder.getSpec().getPayload().toByteArray(), "Custom Coder Bytes");
   }
+
+  /**
+   * Explicitly validate that required coders are registered.
+   *
+   * <p>Called early to give avoid significantly more obscure error later if this precondition is
+   * not satisfied.
+   */
+  public static void verifyModelCodersRegistered() {
+    for (String urn : new ModelCoderRegistrar().getCoderURNs().values())
+      if (!getKnownCoderUrns().inverse().containsKey(urn)) {
+        throw new IllegalStateException(
+            "Model coder not registered for "
+                + urn
+                + ". Perhaps this is a fat jar built with missing ServiceLoader entries?");
+      }
+  }
 }
diff --git a/sdks/java/harness/src/main/java/org/apache/beam/fn/harness/FnHarness.java b/sdks/java/harness/src/main/java/org/apache/beam/fn/harness/FnHarness.java
index 3301fd17e1bcf..9df9f12bc52b6 100644
--- a/sdks/java/harness/src/main/java/org/apache/beam/fn/harness/FnHarness.java
+++ b/sdks/java/harness/src/main/java/org/apache/beam/fn/harness/FnHarness.java
@@ -62,6 +62,7 @@
 import org.apache.beam.sdk.options.ExecutorOptions;
 import org.apache.beam.sdk.options.ExperimentalOptions;
 import org.apache.beam.sdk.options.PipelineOptions;
+import org.apache.beam.sdk.util.construction.CoderTranslation;
 import org.apache.beam.sdk.util.construction.PipelineOptionsTranslation;
 import org.apache.beam.vendor.grpc.v1p60p1.com.google.protobuf.TextFormat;
 import org.apache.beam.vendor.grpc.v1p60p1.io.grpc.ManagedChannel;
@@ -288,6 +289,7 @@ public static void main(
       LOG.info("Fn Harness started");
       // Register standard file systems.
       FileSystems.setDefaultPipelineOptions(options);
+      CoderTranslation.verifyModelCodersRegistered();
       EnumMap<
               BeamFnApi.InstructionRequest.RequestCase,
               ThrowingFunction<InstructionRequest, BeamFnApi.InstructionResponse.Builder>>