diff --git a/proto-docs/storagegroup.md b/proto-docs/storagegroup.md
index af34ee3..e1d27ae 100644
--- a/proto-docs/storagegroup.md
+++ b/proto-docs/storagegroup.md
@@ -7,7 +7,6 @@
 
   - Messages
     - [StorageGroup](#storagegroup.StorageGroup)
-    - [StorageGroup.Lifetime](#storagegroup.StorageGroup.Lifetime)
     
 
 - [Scalar Value Types](#scalar-value-types)
@@ -33,36 +32,11 @@
 | ----- | ---- | ----- | ----------- |
 | ValidationDataSize | [uint64](#uint64) |  | ValidationDataSize is size of the all object's payloads included into storage group |
 | ValidationHash | [bytes](#bytes) |  | ValidationHash is homomorphic hash of all object's payloads included into storage group |
-| lifetime | [StorageGroup.Lifetime](#storagegroup.StorageGroup.Lifetime) |  | Lifetime is time until storage group is valid |
+| ExpirationEpoch | [uint64](#uint64) |  | ExpirationEpoch carries last NeoFS epoch number of the storage group lifetime. |
 | Members | [refs.ObjectID](#refs.ObjectID) | repeated | Members carries the list of identifiers of the object storage group members. The list is strictly ordered. |
 
-
-<a name="storagegroup.StorageGroup.Lifetime"></a>
-
-### Message StorageGroup.Lifetime
-
-
-
-| Field | Type | Label | Description |
-| ----- | ---- | ----- | ----------- |
-| unit | [StorageGroup.Lifetime.Unit](#storagegroup.StorageGroup.Lifetime.Unit) |  | Unit is lifetime type |
-| Value | [int64](#int64) |  | Value for lifetime |
-
  <!-- end messages -->
 
-
-<a name="storagegroup.StorageGroup.Lifetime.Unit"></a>
-
-### StorageGroup.Lifetime.Unit
-
-
-| Name | Number | Description |
-| ---- | ------ | ----------- |
-| Unlimited | 0 | Unlimited set if storage group always valid |
-| NeoFSEpoch | 1 | NeoFSEpoch set if storage group is valid until lifetime NeoFS epoch |
-| UnixTime | 2 | UnixTime set if storage group is valid until lifetime unix timestamp |
-
-
  <!-- end enums -->
 
 
diff --git a/storagegroup/types.proto b/storagegroup/types.proto
index 98604e6..0848ac0 100644
--- a/storagegroup/types.proto
+++ b/storagegroup/types.proto
@@ -11,24 +11,8 @@ message StorageGroup {
     // ValidationHash is homomorphic hash of all object's payloads included into storage group
     bytes ValidationHash = 2;
 
-    message Lifetime {
-        enum Unit {
-            // Unlimited set if storage group always valid
-            Unlimited = 0;
-            // NeoFSEpoch set if storage group is valid until lifetime NeoFS epoch
-            NeoFSEpoch = 1;
-            // UnixTime set if storage group is valid until lifetime unix timestamp
-            UnixTime = 2;
-        }
-
-        // Unit is lifetime type
-        Unit unit = 1;
-        // Value for lifetime
-        int64 Value = 2;
-    }
-
-    // Lifetime is time until storage group is valid
-    Lifetime lifetime = 3;
+    // ExpirationEpoch carries last NeoFS epoch number of the storage group lifetime.
+    uint64 ExpirationEpoch = 3;
 
     // Members carries the list of identifiers of the object storage group members.
     // The list is strictly ordered.