diff --git a/src/dstack/_internal/core/models/instances.py b/src/dstack/_internal/core/models/instances.py
index f1f802d54..ef4fbc17b 100644
--- a/src/dstack/_internal/core/models/instances.py
+++ b/src/dstack/_internal/core/models/instances.py
@@ -216,6 +216,18 @@ def finished_statuses(cls) -> List["InstanceStatus"]:
         return [cls.TERMINATING, cls.TERMINATED]
 
 
+class InstanceTerminationReason(str, Enum):
+    IDLE_TIMEOUT = "idle_timeout"
+    PROOVISIONING_TIMEOUT = "provisioning_timeout"
+    ERROR = "error"
+    JOB_FINISHED = "job_finished"
+    TERMINATION_TIMEOUT = "termination_timeout"
+    STARTING_TIMEOUT = "starting_timeout"
+    NO_OFFERS = "no_offers"
+    MASTER_FAILED = "master_failed"
+    NO_BALANCE = "no_balance"
+
+
 class Instance(CoreModel):
     id: UUID
     project_name: str
@@ -231,6 +243,7 @@ class Instance(CoreModel):
     unreachable: bool = False
     health_status: HealthStatus = HealthStatus.HEALTHY
     termination_reason: Optional[str] = None
+    termination_reason_message: Optional[str] = None
     created: datetime.datetime
     region: Optional[str] = None
     availability_zone: Optional[str] = None
diff --git a/src/dstack/_internal/core/models/runs.py b/src/dstack/_internal/core/models/runs.py
index 969b336b9..dce8ef8e0 100644
--- a/src/dstack/_internal/core/models/runs.py
+++ b/src/dstack/_internal/core/models/runs.py
@@ -138,6 +138,7 @@ class JobTerminationReason(str, Enum):
     TERMINATED_BY_SERVER = "terminated_by_server"
     INACTIVITY_DURATION_EXCEEDED = "inactivity_duration_exceeded"
     TERMINATED_DUE_TO_UTILIZATION_POLICY = "terminated_due_to_utilization_policy"
+    NO_BALANCE = "no_balance"
     # Set by the runner
     CONTAINER_EXITED_WITH_ERROR = "container_exited_with_error"
     PORTS_BINDING_FAILED = "ports_binding_failed"
@@ -161,6 +162,7 @@ def to_status(self) -> JobStatus:
             self.TERMINATED_BY_SERVER: JobStatus.TERMINATED,
             self.INACTIVITY_DURATION_EXCEEDED: JobStatus.TERMINATED,
             self.TERMINATED_DUE_TO_UTILIZATION_POLICY: JobStatus.TERMINATED,
+            self.NO_BALANCE: JobStatus.TERMINATED,
             self.CONTAINER_EXITED_WITH_ERROR: JobStatus.FAILED,
             self.PORTS_BINDING_FAILED: JobStatus.FAILED,
             self.CREATING_CONTAINER_ERROR: JobStatus.FAILED,
diff --git a/src/dstack/_internal/server/background/tasks/process_instances.py b/src/dstack/_internal/server/background/tasks/process_instances.py
index ec7ca8f7e..c08b5f0b7 100644
--- a/src/dstack/_internal/server/background/tasks/process_instances.py
+++ b/src/dstack/_internal/server/background/tasks/process_instances.py
@@ -45,6 +45,7 @@
     InstanceOfferWithAvailability,
     InstanceRuntime,
     InstanceStatus,
+    InstanceTerminationReason,
     RemoteConnectionInfo,
     SSHKey,
 )
@@ -240,7 +241,7 @@ def _check_and_mark_terminating_if_idle_duration_expired(instance: InstanceModel
     delta = datetime.timedelta(seconds=idle_seconds)
     if idle_duration > delta:
         instance.status = InstanceStatus.TERMINATING
-        instance.termination_reason = "Idle timeout"
+        instance.termination_reason = InstanceTerminationReason.IDLE_TIMEOUT.value
         logger.info(
             "Instance %s idle duration expired: idle time %ss. Terminating",
             instance.name,
@@ -262,7 +263,7 @@ async def _add_remote(instance: InstanceModel) -> None:
     retry_duration_deadline = instance.created_at + timedelta(seconds=PROVISIONING_TIMEOUT_SECONDS)
     if retry_duration_deadline < get_current_datetime():
         instance.status = InstanceStatus.TERMINATED
-        instance.termination_reason = "Provisioning timeout expired"
+        instance.termination_reason = InstanceTerminationReason.PROOVISIONING_TIMEOUT.value
         logger.warning(
             "Failed to start instance %s in %d seconds. Terminating...",
             instance.name,
@@ -285,7 +286,8 @@ async def _add_remote(instance: InstanceModel) -> None:
                 ssh_proxy_pkeys = None
         except (ValueError, PasswordRequiredException):
             instance.status = InstanceStatus.TERMINATED
-            instance.termination_reason = "Unsupported private SSH key type"
+            instance.termination_reason = InstanceTerminationReason.ERROR.value
+            instance.termination_reason_message = "Unsupported private SSH key type"
             logger.warning(
                 "Failed to add instance %s: unsupported private SSH key type",
                 instance.name,
@@ -343,7 +345,10 @@ async def _add_remote(instance: InstanceModel) -> None:
         )
     if instance_network is not None and internal_ip is None:
         instance.status = InstanceStatus.TERMINATED
-        instance.termination_reason = "Failed to locate internal IP address on the given network"
+        instance.termination_reason = InstanceTerminationReason.ERROR.value
+        instance.termination_reason_message = (
+            "Failed to locate internal IP address on the given network"
+        )
         logger.warning(
             "Failed to add instance %s: failed to locate internal IP address on the given network",
             instance.name,
@@ -356,7 +361,8 @@ async def _add_remote(instance: InstanceModel) -> None:
     if internal_ip is not None:
         if not is_ip_among_addresses(ip_address=internal_ip, addresses=host_network_addresses):
             instance.status = InstanceStatus.TERMINATED
-            instance.termination_reason = (
+            instance.termination_reason = InstanceTerminationReason.ERROR.value
+            instance.termination_reason_message = (
                 "Specified internal IP not found among instance interfaces"
             )
             logger.warning(
@@ -378,7 +384,8 @@ async def _add_remote(instance: InstanceModel) -> None:
         instance.total_blocks = blocks
     else:
         instance.status = InstanceStatus.TERMINATED
-        instance.termination_reason = "Cannot split into blocks"
+        instance.termination_reason = InstanceTerminationReason.ERROR.value
+        instance.termination_reason_message = "Cannot split into blocks"
         logger.warning(
             "Failed to add instance %s: cannot split into blocks",
             instance.name,
@@ -497,7 +504,8 @@ async def _create_instance(session: AsyncSession, instance: InstanceModel) -> No
         requirements = get_instance_requirements(instance)
     except ValidationError as e:
         instance.status = InstanceStatus.TERMINATED
-        instance.termination_reason = (
+        instance.termination_reason = InstanceTerminationReason.ERROR.value
+        instance.termination_reason_message = (
             f"Error to parse profile, requirements or instance_configuration: {e}"
         )
         logger.warning(
@@ -645,7 +653,7 @@ async def _create_instance(session: AsyncSession, instance: InstanceModel) -> No
             )
         return
 
-    _mark_terminated(instance, "All offers failed" if offers else "No offers found")
+    _mark_terminated(instance, InstanceTerminationReason.NO_OFFERS.value)
     if (
         instance.fleet
         and _is_fleet_master_instance(instance)
@@ -656,7 +664,7 @@ async def _create_instance(session: AsyncSession, instance: InstanceModel) -> No
         for sibling_instance in instance.fleet.instances:
             if sibling_instance.id == instance.id:
                 continue
-            _mark_terminated(sibling_instance, "Master instance failed to start")
+            _mark_terminated(sibling_instance, InstanceTerminationReason.MASTER_FAILED.value)
 
 
 def _mark_terminated(instance: InstanceModel, termination_reason: str) -> None:
@@ -681,7 +689,7 @@ async def _check_instance(session: AsyncSession, instance: InstanceModel) -> Non
     ):
         # A busy instance could have no active jobs due to this bug: https://github.com/dstackai/dstack/issues/2068
         instance.status = InstanceStatus.TERMINATING
-        instance.termination_reason = "Instance job finished"
+        instance.termination_reason = InstanceTerminationReason.JOB_FINISHED.value
         logger.info(
             "Detected busy instance %s with finished job. Marked as TERMINATING",
             instance.name,
@@ -810,7 +818,7 @@ async def _check_instance(session: AsyncSession, instance: InstanceModel) -> Non
         deadline = instance.termination_deadline
         if get_current_datetime() > deadline:
             instance.status = InstanceStatus.TERMINATING
-            instance.termination_reason = "Termination deadline"
+            instance.termination_reason = InstanceTerminationReason.TERMINATION_TIMEOUT.value
             logger.warning(
                 "Instance %s shim waiting timeout. Marked as TERMINATING",
                 instance.name,
@@ -839,7 +847,7 @@ async def _wait_for_instance_provisioning_data(
             "Instance %s failed because instance has not become running in time", instance.name
         )
         instance.status = InstanceStatus.TERMINATING
-        instance.termination_reason = "Instance has not become running in time"
+        instance.termination_reason = InstanceTerminationReason.STARTING_TIMEOUT.value
         return
 
     backend = await backends_services.get_project_backend_by_type(
@@ -852,7 +860,8 @@ async def _wait_for_instance_provisioning_data(
             instance.name,
         )
         instance.status = InstanceStatus.TERMINATING
-        instance.termination_reason = "Backend not available"
+        instance.termination_reason = InstanceTerminationReason.ERROR.value
+        instance.termination_reason_message = "Backend not available"
         return
     try:
         await run_async(
@@ -869,7 +878,8 @@ async def _wait_for_instance_provisioning_data(
             repr(e),
         )
         instance.status = InstanceStatus.TERMINATING
-        instance.termination_reason = "Error while waiting for instance to become running"
+        instance.termination_reason = InstanceTerminationReason.ERROR.value
+        instance.termination_reason_message = "Error while waiting for instance to become running"
     except Exception:
         logger.exception(
             "Got exception when updating instance %s provisioning data", instance.name
diff --git a/src/dstack/_internal/server/background/tasks/process_running_jobs.py b/src/dstack/_internal/server/background/tasks/process_running_jobs.py
index aa69f2f33..080f8ffd2 100644
--- a/src/dstack/_internal/server/background/tasks/process_running_jobs.py
+++ b/src/dstack/_internal/server/background/tasks/process_running_jobs.py
@@ -18,6 +18,7 @@
 from dstack._internal.core.models.files import FileArchiveMapping
 from dstack._internal.core.models.instances import (
     InstanceStatus,
+    InstanceTerminationReason,
     RemoteConnectionInfo,
     SSHConnectionParams,
 )
@@ -58,6 +59,7 @@
 from dstack._internal.server.services.jobs import (
     find_job,
     get_job_attached_volumes,
+    get_job_provisioning_data,
     get_job_runtime_data,
     job_model_to_job_submission,
 )
@@ -381,9 +383,22 @@ async def _process_running_job(session: AsyncSession, job_model: JobModel):
                         fmt(job_model),
                         job_submission.age,
                     )
-                    # TODO: Replace with JobTerminationReason.INSTANCE_UNREACHABLE in 0.20 or
-                    # when CLI <= 0.19.8 is no longer supported
-                    job_model.termination_reason = JobTerminationReason.INTERRUPTED_BY_NO_CAPACITY
+                    if (
+                        job_model.instance is not None
+                        and job_model.instance.termination_reason
+                        == InstanceTerminationReason.NO_BALANCE.value
+                    ):
+                        # if instance was terminated due to no balance, set job termination reason accodingly
+                        job_model.termination_reason = JobTerminationReason.NO_BALANCE
+                    else:
+                        job_provisioning_data = get_job_provisioning_data(job_model)
+                        # use JobTerminationReason.INSTANCE_UNREACHABLE for on-demand instances only
+                        job_model.termination_reason = (
+                            JobTerminationReason.INSTANCE_UNREACHABLE
+                            if job_provisioning_data
+                            and not job_provisioning_data.instance_type.resources.spot
+                            else JobTerminationReason.INTERRUPTED_BY_NO_CAPACITY
+                        )
                     job_model.status = JobStatus.TERMINATING
                 else:
                     logger.warning(
diff --git a/src/dstack/_internal/server/migrations/versions/a16a05249504_instance_termination_reason_message.py b/src/dstack/_internal/server/migrations/versions/a16a05249504_instance_termination_reason_message.py
new file mode 100644
index 000000000..7b5cfae47
--- /dev/null
+++ b/src/dstack/_internal/server/migrations/versions/a16a05249504_instance_termination_reason_message.py
@@ -0,0 +1,34 @@
+"""instance.termination_reason_message
+
+Revision ID: a16a05249504
+Revises: 2498ab323443
+Create Date: 2025-10-13 15:29:56.691164
+
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "a16a05249504"
+down_revision = "2498ab323443"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table("instances", schema=None) as batch_op:
+        batch_op.add_column(
+            sa.Column("termination_reason_message", sa.String(length=4000), nullable=True)
+        )
+
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table("instances", schema=None) as batch_op:
+        batch_op.drop_column("termination_reason_message")
+
+    # ### end Alembic commands ###
diff --git a/src/dstack/_internal/server/models.py b/src/dstack/_internal/server/models.py
index b21ba81a4..b6537b65b 100644
--- a/src/dstack/_internal/server/models.py
+++ b/src/dstack/_internal/server/models.py
@@ -614,7 +614,9 @@ class InstanceModel(BaseModel):
 
     # instance termination handling
     termination_deadline: Mapped[Optional[datetime]] = mapped_column(NaiveDateTime)
+    # TODO: Migrate to EnumAsString(InstanceTerminationReason, 100) after enough releases to ensure backward compatibility
     termination_reason: Mapped[Optional[str]] = mapped_column(String(4000))
+    termination_reason_message: Mapped[Optional[str]] = mapped_column(String(4000))
     # Deprecated since 0.19.22, not used
     health_status: Mapped[Optional[str]] = mapped_column(String(4000))
     health: Mapped[HealthStatus] = mapped_column(
diff --git a/src/dstack/_internal/server/services/instances.py b/src/dstack/_internal/server/services/instances.py
index 7c679b0cc..aba50cfc5 100644
--- a/src/dstack/_internal/server/services/instances.py
+++ b/src/dstack/_internal/server/services/instances.py
@@ -122,6 +122,7 @@ def instance_model_to_instance(instance_model: InstanceModel) -> Instance:
         unreachable=instance_model.unreachable,
         health_status=instance_model.health,
         termination_reason=instance_model.termination_reason,
+        termination_reason_message=instance_model.termination_reason_message,
         created=instance_model.created_at,
         total_blocks=instance_model.total_blocks,
         busy_blocks=instance_model.busy_blocks,
diff --git a/src/dstack/_internal/server/services/jobs/__init__.py b/src/dstack/_internal/server/services/jobs/__init__.py
index ffea0c72e..e82300513 100644
--- a/src/dstack/_internal/server/services/jobs/__init__.py
+++ b/src/dstack/_internal/server/services/jobs/__init__.py
@@ -749,6 +749,8 @@ def _get_job_status_message(job_model: JobModel) -> str:
             return "stopped"
         elif job_model.termination_reason == JobTerminationReason.ABORTED_BY_USER:
             return "aborted"
+        elif job_model.termination_reason == JobTerminationReason.NO_BALANCE:
+            return "no balance"
     return job_model.status.value
 
 
diff --git a/src/tests/_internal/core/models/test_runs.py b/src/tests/_internal/core/models/test_runs.py
index 23b27c018..5e847beb4 100644
--- a/src/tests/_internal/core/models/test_runs.py
+++ b/src/tests/_internal/core/models/test_runs.py
@@ -43,6 +43,7 @@ def test_get_error_returns_expected_messages():
         JobTerminationReason.ABORTED_BY_USER,
         JobTerminationReason.TERMINATED_BY_SERVER,
         JobTerminationReason.CONTAINER_EXITED_WITH_ERROR,
+        JobTerminationReason.NO_BALANCE,
     ]
 
     for reason in JobTerminationReason:
diff --git a/src/tests/_internal/server/background/tasks/test_process_instances.py b/src/tests/_internal/server/background/tasks/test_process_instances.py
index 690cb71d9..68dc5dea7 100644
--- a/src/tests/_internal/server/background/tasks/test_process_instances.py
+++ b/src/tests/_internal/server/background/tasks/test_process_instances.py
@@ -27,6 +27,7 @@
     InstanceOffer,
     InstanceOfferWithAvailability,
     InstanceStatus,
+    InstanceTerminationReason,
     InstanceType,
     Resources,
 )
@@ -251,7 +252,7 @@ async def test_check_shim_terminate_instance_by_deadline(self, test_db, session:
         assert instance is not None
         assert instance.status == InstanceStatus.TERMINATING
         assert instance.termination_deadline == termination_deadline_time
-        assert instance.termination_reason == "Termination deadline"
+        assert instance.termination_reason == InstanceTerminationReason.TERMINATION_TIMEOUT.value
 
     @pytest.mark.asyncio
     @pytest.mark.parametrize(
@@ -510,7 +511,7 @@ async def test_terminate_by_idle_timeout(self, test_db, session: AsyncSession):
         await session.refresh(instance)
         assert instance is not None
         assert instance.status == InstanceStatus.TERMINATING
-        assert instance.termination_reason == "Idle timeout"
+        assert instance.termination_reason == InstanceTerminationReason.IDLE_TIMEOUT.value
 
 
 class TestSSHInstanceTerminateProvisionTimeoutExpired:
@@ -531,7 +532,7 @@ async def test_terminate_by_idle_timeout(self, test_db, session: AsyncSession):
 
         await session.refresh(instance)
         assert instance.status == InstanceStatus.TERMINATED
-        assert instance.termination_reason == "Provisioning timeout expired"
+        assert instance.termination_reason == InstanceTerminationReason.PROOVISIONING_TIMEOUT.value
 
 
 class TestTerminate:
@@ -800,7 +801,7 @@ async def test_fails_if_all_offers_fail(self, session: AsyncSession, err: Except
 
         await session.refresh(instance)
         assert instance.status == InstanceStatus.TERMINATED
-        assert instance.termination_reason == "All offers failed"
+        assert instance.termination_reason == InstanceTerminationReason.NO_OFFERS.value
 
     async def test_fails_if_no_offers(self, session: AsyncSession):
         project = await create_project(session=session)
@@ -813,19 +814,22 @@ async def test_fails_if_no_offers(self, session: AsyncSession):
 
         await session.refresh(instance)
         assert instance.status == InstanceStatus.TERMINATED
-        assert instance.termination_reason == "No offers found"
+        assert instance.termination_reason == InstanceTerminationReason.NO_OFFERS.value
 
     @pytest.mark.parametrize(
         ("placement", "expected_termination_reasons"),
         [
             pytest.param(
                 InstanceGroupPlacement.CLUSTER,
-                {"No offers found": 1, "Master instance failed to start": 3},
+                {
+                    InstanceTerminationReason.NO_OFFERS.value: 1,
+                    InstanceTerminationReason.MASTER_FAILED.value: 3,
+                },
                 id="cluster",
             ),
             pytest.param(
                 None,
-                {"No offers found": 4},
+                {InstanceTerminationReason.NO_OFFERS.value: 4},
                 id="non-cluster",
             ),
         ],
diff --git a/src/tests/_internal/server/background/tasks/test_process_running_jobs.py b/src/tests/_internal/server/background/tasks/test_process_running_jobs.py
index e3cc011be..d13959b48 100644
--- a/src/tests/_internal/server/background/tasks/test_process_running_jobs.py
+++ b/src/tests/_internal/server/background/tasks/test_process_running_jobs.py
@@ -528,7 +528,7 @@ async def test_pulling_shim_failed(self, test_db, session: AsyncSession):
             assert SSHTunnelMock.call_count == 3
         await session.refresh(job)
         assert job.status == JobStatus.TERMINATING
-        assert job.termination_reason == JobTerminationReason.INTERRUPTED_BY_NO_CAPACITY
+        assert job.termination_reason == JobTerminationReason.INSTANCE_UNREACHABLE
         assert job.remove_at is None
 
     @pytest.mark.asyncio
diff --git a/src/tests/_internal/server/routers/test_fleets.py b/src/tests/_internal/server/routers/test_fleets.py
index 934f333b6..7b34b20a6 100644
--- a/src/tests/_internal/server/routers/test_fleets.py
+++ b/src/tests/_internal/server/routers/test_fleets.py
@@ -402,6 +402,7 @@ async def test_creates_fleet(self, test_db, session: AsyncSession, client: Async
                     "unreachable": False,
                     "health_status": "healthy",
                     "termination_reason": None,
+                    "termination_reason_message": None,
                     "created": "2023-01-02T03:04:00+00:00",
                     "backend": None,
                     "region": None,
@@ -537,6 +538,7 @@ async def test_creates_ssh_fleet(self, test_db, session: AsyncSession, client: A
                     "unreachable": False,
                     "health_status": "healthy",
                     "termination_reason": None,
+                    "termination_reason_message": None,
                     "created": "2023-01-02T03:04:00+00:00",
                     "region": "remote",
                     "availability_zone": None,
@@ -708,6 +710,7 @@ async def test_updates_ssh_fleet(self, test_db, session: AsyncSession, client: A
                     "unreachable": False,
                     "health_status": "healthy",
                     "termination_reason": None,
+                    "termination_reason_message": None,
                     "created": "2023-01-02T03:04:00+00:00",
                     "region": "remote",
                     "availability_zone": None,
@@ -741,6 +744,7 @@ async def test_updates_ssh_fleet(self, test_db, session: AsyncSession, client: A
                     "unreachable": False,
                     "health_status": "healthy",
                     "termination_reason": None,
+                    "termination_reason_message": None,
                     "created": "2023-01-02T03:04:00+00:00",
                     "region": "remote",
                     "availability_zone": None,