diff --git a/msamp/megatron/optimizer/distrib_optimizer.py b/msamp/megatron/optimizer/distrib_optimizer.py
index 560ecce5..3b8f8148 100644
--- a/msamp/megatron/optimizer/distrib_optimizer.py
+++ b/msamp/megatron/optimizer/distrib_optimizer.py
@@ -10,6 +10,7 @@
 from megatron.core import mpu, tensor_parallel
 from megatron.optimizer.optimizer import MixedPrecisionOptimizer, _zero_grad_group_helper
 from megatron.optimizer.distrib_optimizer import DistributedOptimizer, Range
+from megatron.utils import print_rank_0
 
 from msamp.common.dtype import Dtypes
 from msamp.common.tensor import ScalingTensor, ScalingMeta
@@ -350,12 +351,60 @@ def get_model_parallel_group(self):
         return None
 
     def state_dict(self):
-        """Return the optimizer's state dict."""
-        raise NotImplementedError
+        """The state dict must contain the fp32-from-float16 and fp16-from-fp8 shards."""
+        state_dict = {}
+        state_dict['optimizer'] = self.optimizer.state_dict()
+        if self.grad_scaler:
+            state_dict['grad_scaler'] = self.grad_scaler.state_dict()
+        # shared master weight
+        state_dict['shard_fp32_from_float16_groups'] = \
+            self.shard_fp32_from_float16_groups
+        state_dict['shard_hp_from_fp8_groups'] = \
+            self.shard_hp_from_fp8_groups
+        return state_dict
 
     def load_state_dict(self, state_dict):
-        """Load the optimizer's state dict."""
-        raise NotImplementedError
+        """Load the state dict."""
+        optimizer_key = 'optimizer'
+        if optimizer_key not in state_dict:
+            optimizer_key = 'optimizer_state_dict'
+            print_rank_0('***WARNING*** loading optimizer from '
+                         'an old checkpoint ...')
+        # convert optimizer states
+        ckpt_state_dict = state_dict[optimizer_key]
+        self.optimizer.load_state_dict(ckpt_state_dict)
+
+        # Grad scaler.
+        if 'grad_scaler' not in state_dict:
+            if self.fp16:
+                print_rank_0('***WARNING*** found an old checkpoint, will not '
+                             'load grad scaler ...')
+        else:
+            if self.grad_scaler:
+                self.grad_scaler.load_state_dict(state_dict['grad_scaler'])
+            else:
+                print_rank_0(
+                    '***WARNING*** fould the grad scaler in the '
+                    'checkpoint but it is None in the class. '
+                    'Skipping loading grad scaler ...'
+                )
+
+        # Copy data for the main params.
+        for current_group, saved_group in zip(
+            self.shard_fp32_from_float16_groups, state_dict['shard_fp32_from_float16_groups']
+        ):
+            for current_param, saved_param in zip(current_group, saved_group):
+                current_param.data.copy_(saved_param.data)
+
+        for current_group, saved_group in zip(self.shard_hp_from_fp8_groups, state_dict['shard_hp_from_fp8_groups']):
+            for current_param, saved_param in zip(current_group, saved_group):
+                if current_param.data.qtype == saved_param.data.qtype:
+                    current_param.data.copy_(saved_param.data)
+                else:
+                    # when the data type of optimizer's master weight and checkpoint's is different
+                    current_param.data.copy_(
+                        saved_param.data.to(current_param.data.device).cast(current_param.data.qtype)
+                    )
 
     def zero_grad(self, set_to_none=True):
         """Zero grads.