diff --git a/tests/worker/test_jobs.py b/tests/worker/test_jobs.py
index eeaa3e2d..f746c036 100644
--- a/tests/worker/test_jobs.py
+++ b/tests/worker/test_jobs.py
@@ -965,39 +965,313 @@ async def test_create_mapped_variants_for_scoreset_no_mapping_output(
     assert score_set.mapping_state == MappingState.failed
 
 
-@pytest.mark.skip
 @pytest.mark.asyncio
-async def test_mapping_manager_empty_queue(setup_worker_db, standalone_worker_context, session):
-    queued_job = await variant_mapper_manager(standalone_worker_context)
+async def test_mapping_manager_empty_queue(setup_worker_db, standalone_worker_context):
+    result = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
 
-    # No new jobs should have been created if nothing is in the queue.
-    assert queued_job is None
-    session.commit()
+    # No new jobs should have been created if nothing is in the queue, and the queue should remain empty.
+    assert result["enqueued_job"] is None
+    assert result["success"]
+    assert (await standalone_worker_context["redis"].llen(MAPPING_QUEUE_NAME)) == 0
+    assert (await standalone_worker_context["redis"].get(MAPPING_CURRENT_ID_NAME)).decode("utf-8") == ""
 
 
-@pytest.mark.skip
 @pytest.mark.asyncio
-async def test_mapping_manager_occupied_queue_mapping_in_progress(setup_worker_db, standalone_worker_context, session):
-    await standalone_worker_context["redis"].lpush(MAPPING_QUEUE_NAME, "mavedb:test-urn")
+async def test_mapping_manager_empty_queue_error_during_setup(setup_worker_db, standalone_worker_context):
+    await standalone_worker_context["redis"].set(MAPPING_CURRENT_ID_NAME, "")
+    with patch.object(ArqRedis, "rpop", Exception()):
+        result = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
 
+    # No new jobs should have been created if nothing is in the queue, and the queue should remain empty.
+    assert result["enqueued_job"] is None
+    assert not result["success"]
+    assert (await standalone_worker_context["redis"].llen(MAPPING_QUEUE_NAME)) == 0
+    assert (await standalone_worker_context["redis"].get(MAPPING_CURRENT_ID_NAME)).decode("utf-8") == ""
+
+
+@pytest.mark.asyncio
+async def test_mapping_manager_occupied_queue_mapping_in_progress(
+    setup_worker_db, standalone_worker_context, session, async_client, data_files
+):
+    score_set = await setup_records_files_and_variants(
+        session,
+        async_client,
+        data_files,
+        TEST_MINIMAL_SEQ_SCORESET,
+        standalone_worker_context,
+    )
+
+    await standalone_worker_context["redis"].set(MAPPING_CURRENT_ID_NAME, "5")
     with patch.object(arq.jobs.Job, "status", return_value=arq.jobs.JobStatus.in_progress):
-        queued_job = await variant_mapper_manager(standalone_worker_context)
+        result = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
 
-    # Execution should be deferred if a job is in progress.
-    assert await queued_job.status() is arq.jobs.JobStatus.deferred
-    session.commit()
+    # Execution should be deferred if a job is in progress, and the queue should contain one entry which is the deferred ID.
+    assert result["enqueued_job"] is not None
+    assert (
+        await arq.jobs.Job(result["enqueued_job"], standalone_worker_context["redis"]).status()
+    ) == arq.jobs.JobStatus.deferred
+    assert result["success"]
+    assert (await standalone_worker_context["redis"].llen(MAPPING_QUEUE_NAME)) == 1
+    assert (await standalone_worker_context["redis"].rpop(MAPPING_QUEUE_NAME)).decode("utf-8") == str(score_set.id)
+    assert (await standalone_worker_context["redis"].get(MAPPING_CURRENT_ID_NAME)).decode("utf-8") == "5"
+    assert score_set.mapping_state == MappingState.queued
+    assert score_set.mapping_errors is None
 
 
-@pytest.mark.skip
 @pytest.mark.asyncio
 async def test_mapping_manager_occupied_queue_mapping_not_in_progress(
-    setup_worker_db, standalone_worker_context, session
+    setup_worker_db, standalone_worker_context, session, async_client, data_files
 ):
-    await standalone_worker_context["redis"].lpush(MAPPING_QUEUE_NAME, "mavedb:test-urn")
+    score_set = await setup_records_files_and_variants(
+        session,
+        async_client,
+        data_files,
+        TEST_MINIMAL_SEQ_SCORESET,
+        standalone_worker_context,
+    )
 
+    await standalone_worker_context["redis"].set(MAPPING_CURRENT_ID_NAME, "")
     with patch.object(arq.jobs.Job, "status", return_value=arq.jobs.JobStatus.not_found):
-        queued_job = await variant_mapper_manager(standalone_worker_context)
+        result = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
 
-    # VRS Mapping jobs have the same ID.
-    assert queued_job.job_id == "vrs_map"
-    session.commit()
+    # Mapping job should be queued if none is currently running, and the queue should now be empty.
+    assert result["enqueued_job"] is not None
+    assert (
+        await arq.jobs.Job(result["enqueued_job"], standalone_worker_context["redis"]).status()
+    ) == arq.jobs.JobStatus.queued
+    assert result["success"]
+    assert (await standalone_worker_context["redis"].llen(MAPPING_QUEUE_NAME)) == 0
+    # We don't actually start processing these score sets.
+    assert score_set.mapping_state == MappingState.queued
+    assert score_set.mapping_errors is None
+
+
+@pytest.mark.asyncio
+async def test_mapping_manager_occupied_queue_mapping_in_progress_error_during_enqueue(
+    setup_worker_db, standalone_worker_context, session, async_client, data_files
+):
+    score_set = await setup_records_files_and_variants(
+        session,
+        async_client,
+        data_files,
+        TEST_MINIMAL_SEQ_SCORESET,
+        standalone_worker_context,
+    )
+
+    await standalone_worker_context["redis"].set(MAPPING_CURRENT_ID_NAME, "5")
+    with patch.object(arq.jobs.Job, "status", return_value=arq.jobs.JobStatus.in_progress), patch.object(
+        ArqRedis, "enqueue_job", return_value=awaitable_exception()
+    ):
+        result = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
+
+    # Execution should be deferred if a job is in progress, and the queue should contain one entry which is the deferred ID.
+    assert result["enqueued_job"] is None
+    assert not result["success"]
+    assert (await standalone_worker_context["redis"].llen(MAPPING_QUEUE_NAME)) == 0
+    assert (await standalone_worker_context["redis"].get(MAPPING_CURRENT_ID_NAME)).decode("utf-8") == "5"
+    assert score_set.mapping_state == MappingState.failed
+    assert score_set.mapping_errors is not None
+
+
+@pytest.mark.asyncio
+async def test_mapping_manager_occupied_queue_mapping_not_in_progress_error_during_enqueue(
+    setup_worker_db, standalone_worker_context, session, async_client, data_files
+):
+    score_set = await setup_records_files_and_variants(
+        session,
+        async_client,
+        data_files,
+        TEST_MINIMAL_SEQ_SCORESET,
+        standalone_worker_context,
+    )
+
+    await standalone_worker_context["redis"].set(MAPPING_CURRENT_ID_NAME, "")
+    with patch.object(arq.jobs.Job, "status", return_value=arq.jobs.JobStatus.not_found), patch.object(
+        ArqRedis, "enqueue_job", return_value=awaitable_exception()
+    ):
+        result = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
+
+    # Enqueue would have failed, the job is unsuccessful, and we remove the queued item.
+    assert result["enqueued_job"] is None
+    assert not result["success"]
+    assert (await standalone_worker_context["redis"].llen(MAPPING_QUEUE_NAME)) == 0
+    assert score_set.mapping_state == MappingState.failed
+    assert score_set.mapping_errors is not None
+
+
+@pytest.mark.asyncio
+async def test_mapping_manager_multiple_score_sets_occupy_queue_mapping_in_progress(
+    setup_worker_db, standalone_worker_context, session, async_client, data_files
+):
+    score_set_id_1 = (
+        await setup_records_files_and_variants(
+            session,
+            async_client,
+            data_files,
+            TEST_MINIMAL_SEQ_SCORESET,
+            standalone_worker_context,
+        )
+    ).id
+    score_set_id_2 = (
+        await setup_records_files_and_variants(
+            session,
+            async_client,
+            data_files,
+            TEST_MINIMAL_SEQ_SCORESET,
+            standalone_worker_context,
+        )
+    ).id
+    score_set_id_3 = (
+        await setup_records_files_and_variants(
+            session,
+            async_client,
+            data_files,
+            TEST_MINIMAL_SEQ_SCORESET,
+            standalone_worker_context,
+        )
+    ).id
+
+    await standalone_worker_context["redis"].set(MAPPING_CURRENT_ID_NAME, "5")
+    with patch.object(arq.jobs.Job, "status", return_value=arq.jobs.JobStatus.in_progress):
+        result1 = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
+        result2 = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
+        result3 = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
+
+    # All three jobs should complete successfully...
+    assert result1["success"]
+    assert result2["success"]
+    assert result3["success"]
+
+    # ...with a new job enqueued...
+    assert result1["enqueued_job"] is not None
+    assert result2["enqueued_job"] is not None
+    assert result3["enqueued_job"] is not None
+
+    # ...of which all should be deferred jobs of the "variant_mapper_manager" variety...
+    assert (
+        await arq.jobs.Job(result1["enqueued_job"], standalone_worker_context["redis"]).status()
+    ) == arq.jobs.JobStatus.deferred
+    assert (
+        await arq.jobs.Job(result2["enqueued_job"], standalone_worker_context["redis"]).status()
+    ) == arq.jobs.JobStatus.deferred
+    assert (
+        await arq.jobs.Job(result3["enqueued_job"], standalone_worker_context["redis"]).status()
+    ) == arq.jobs.JobStatus.deferred
+
+    assert (
+        await arq.jobs.Job(result1["enqueued_job"], standalone_worker_context["redis"]).info()
+    ).function == "variant_mapper_manager"
+    assert (
+        await arq.jobs.Job(result2["enqueued_job"], standalone_worker_context["redis"]).info()
+    ).function == "variant_mapper_manager"
+    assert (
+        await arq.jobs.Job(result3["enqueued_job"], standalone_worker_context["redis"]).info()
+    ).function == "variant_mapper_manager"
+
+    # ...and the queue state should have three jobs, each of our three created score sets.
+    assert (await standalone_worker_context["redis"].llen(MAPPING_QUEUE_NAME)) == 3
+    assert (await standalone_worker_context["redis"].rpop(MAPPING_QUEUE_NAME)).decode("utf-8") == str(score_set_id_1)
+    assert (await standalone_worker_context["redis"].rpop(MAPPING_QUEUE_NAME)).decode("utf-8") == str(score_set_id_2)
+    assert (await standalone_worker_context["redis"].rpop(MAPPING_QUEUE_NAME)).decode("utf-8") == str(score_set_id_3)
+
+    score_set1 = session.scalars(select(ScoreSetDbModel).where(ScoreSetDbModel.id == score_set_id_1)).one()
+    score_set2 = session.scalars(select(ScoreSetDbModel).where(ScoreSetDbModel.id == score_set_id_2)).one()
+    score_set3 = session.scalars(select(ScoreSetDbModel).where(ScoreSetDbModel.id == score_set_id_3)).one()
+    # Each score set should remain queued with no mapping errors.
+    assert score_set1.mapping_state == MappingState.queued
+    assert score_set2.mapping_state == MappingState.queued
+    assert score_set3.mapping_state == MappingState.queued
+    assert score_set1.mapping_errors is None
+    assert score_set2.mapping_errors is None
+    assert score_set3.mapping_errors is None
+
+
+@pytest.mark.asyncio
+async def test_mapping_manager_multiple_score_sets_occupy_queue_mapping_not_in_progress(
+    setup_worker_db, standalone_worker_context, session, async_client, data_files
+):
+    score_set_id_1 = (
+        await setup_records_files_and_variants(
+            session,
+            async_client,
+            data_files,
+            TEST_MINIMAL_SEQ_SCORESET,
+            standalone_worker_context,
+        )
+    ).id
+    score_set_id_2 = (
+        await setup_records_files_and_variants(
+            session,
+            async_client,
+            data_files,
+            TEST_MINIMAL_SEQ_SCORESET,
+            standalone_worker_context,
+        )
+    ).id
+    score_set_id_3 = (
+        await setup_records_files_and_variants(
+            session,
+            async_client,
+            data_files,
+            TEST_MINIMAL_SEQ_SCORESET,
+            standalone_worker_context,
+        )
+    ).id
+
+    await standalone_worker_context["redis"].set(MAPPING_CURRENT_ID_NAME, "")
+    with patch.object(arq.jobs.Job, "status", return_value=arq.jobs.JobStatus.not_found):
+        result1 = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
+
+    # Mock the first job being in-progress
+    await standalone_worker_context["redis"].set(MAPPING_CURRENT_ID_NAME, str(score_set_id_1))
+    with patch.object(arq.jobs.Job, "status", return_value=arq.jobs.JobStatus.in_progress):
+        result2 = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
+        result3 = await variant_mapper_manager(standalone_worker_context, uuid4().hex, 1)
+
+    # All three jobs should complete successfully...
+    assert result1["success"]
+    assert result2["success"]
+    assert result3["success"]
+
+    # ...with a new job enqueued...
+    assert result1["enqueued_job"] is not None
+    assert result2["enqueued_job"] is not None
+    assert result3["enqueued_job"] is not None
+
+    # ...of which the first should be a queued job of the "map_variants_for_score_set" variety and the other two should be
+    # deferred jobs of the "variant_mapper_manager" variety...
+    assert (
+        await arq.jobs.Job(result1["enqueued_job"], standalone_worker_context["redis"]).status()
+    ) == arq.jobs.JobStatus.queued
+    assert (
+        await arq.jobs.Job(result2["enqueued_job"], standalone_worker_context["redis"]).status()
+    ) == arq.jobs.JobStatus.deferred
+    assert (
+        await arq.jobs.Job(result3["enqueued_job"], standalone_worker_context["redis"]).status()
+    ) == arq.jobs.JobStatus.deferred
+
+    assert (
+        await arq.jobs.Job(result1["enqueued_job"], standalone_worker_context["redis"]).info()
+    ).function == "map_variants_for_score_set"
+    assert (
+        await arq.jobs.Job(result2["enqueued_job"], standalone_worker_context["redis"]).info()
+    ).function == "variant_mapper_manager"
+    assert (
+        await arq.jobs.Job(result3["enqueued_job"], standalone_worker_context["redis"]).info()
+    ).function == "variant_mapper_manager"
+
+    # ...and the queue state should have two jobs, neither of which should be the first score set.
+    assert (await standalone_worker_context["redis"].llen(MAPPING_QUEUE_NAME)) == 2
+    assert (await standalone_worker_context["redis"].rpop(MAPPING_QUEUE_NAME)).decode("utf-8") == str(score_set_id_2)
+    assert (await standalone_worker_context["redis"].rpop(MAPPING_QUEUE_NAME)).decode("utf-8") == str(score_set_id_3)
+
+    score_set1 = session.scalars(select(ScoreSetDbModel).where(ScoreSetDbModel.id == score_set_id_1)).one()
+    score_set2 = session.scalars(select(ScoreSetDbModel).where(ScoreSetDbModel.id == score_set_id_2)).one()
+    score_set3 = session.scalars(select(ScoreSetDbModel).where(ScoreSetDbModel.id == score_set_id_3)).one()
+    # We don't actually process any score sets in the manager job, and each should have no mapping errors.
+    assert score_set1.mapping_state == MappingState.queued
+    assert score_set2.mapping_state == MappingState.queued
+    assert score_set3.mapping_state == MappingState.queued
+    assert score_set1.mapping_errors is None
+    assert score_set2.mapping_errors is None
+    assert score_set3.mapping_errors is None