diff --git a/account_balance_query.go b/account_balance_query.go
index 365bf51f8..9043443a7 100644
--- a/account_balance_query.go
+++ b/account_balance_query.go
@@ -2,11 +2,17 @@ package hedera
 
 import "github.com/hashgraph/hedera-sdk-go/proto"
 
+// AccountBalanceQuery gets the balance of a CryptoCurrency account. This returns only the balance, so it is a smaller
+// and faster reply than AccountInfoQuery, which returns the balance plus additional information.
 type AccountBalanceQuery struct {
 	QueryBuilder
 	pb *proto.CryptoGetAccountBalanceQuery
 }
 
+// NewAccountBalanceQuery creates an AccountBalanceQuery builder which can be used to construct and execute
+// an AccountBalanceQuery.
+// It is recommended that you use this for creating new instances of an AccountBalanceQuery
+// instead of manually creating an instance of the struct.
 func NewAccountBalanceQuery() *AccountBalanceQuery {
 	pb := &proto.CryptoGetAccountBalanceQuery{Header: &proto.QueryHeader{}}
 
@@ -16,11 +22,31 @@ func NewAccountBalanceQuery() *AccountBalanceQuery {
 	return &AccountBalanceQuery{inner, pb}
 }
 
+// SetAccountID sets the AccountID for which you wish to query the balance.
+//
+// Note: you can only query an Account or Contract but not both -- if a Contract ID or Account ID has already been set,
+// it will be overwritten by this method.
 func (builder *AccountBalanceQuery) SetAccountID(id AccountID) *AccountBalanceQuery {
-	builder.pb.AccountID = id.toProto()
+	builder.pb.BalanceSource = &proto.CryptoGetAccountBalanceQuery_AccountID{
+		AccountID: id.toProto(),
+	}
+
+	return builder
+}
+
+// SetContractID sets the ContractID for which you wish to query the balance.
+//
+// Note: you can only query an Account or Contract but not both -- if a Contract ID or Account ID has already been set,
+// it will be overwritten by this method.
+func (builder *AccountBalanceQuery) SetContractID(id ContractID) *AccountBalanceQuery {
+	builder.pb.BalanceSource = &proto.CryptoGetAccountBalanceQuery_ContractID{
+		ContractID: id.toProto(),
+	}
+
 	return builder
 }
 
+// Execute executes the AccountBalanceQuery using the provided client
 func (builder *AccountBalanceQuery) Execute(client *Client) (Hbar, error) {
 	resp, err := builder.execute(client)
 	if err != nil {
diff --git a/account_balance_query_test.go b/account_balance_query_test.go
index 36c2b7f63..e5319cdeb 100644
--- a/account_balance_query_test.go
+++ b/account_balance_query_test.go
@@ -16,3 +16,14 @@ func TestNewAccountBalanceQuery(t *testing.T) {
 
 	cupaloy.SnapshotT(t, query.pb.String())
 }
+
+func TestNewAccountBalanceQuery_ForContract(t *testing.T) {
+	mockTransaction, err := newMockTransaction()
+	assert.NoError(t, err)
+
+	query := NewAccountBalanceQuery().
+		SetContractID(ContractID{Contract: 3}).
+		SetQueryPaymentTransaction(mockTransaction)
+
+	cupaloy.SnapshotT(t, query.pb.String())
+}
diff --git a/proto/CryptoGetAccountBalance.pb.go b/proto/CryptoGetAccountBalance.pb.go
index 64b26e0e8..9c19db9ed 100644
--- a/proto/CryptoGetAccountBalance.pb.go
+++ b/proto/CryptoGetAccountBalance.pb.go
@@ -26,8 +26,11 @@ type CryptoGetAccountBalanceQuery struct {
 	sizeCache     protoimpl.SizeCache
 	unknownFields protoimpl.UnknownFields
 
-	Header    *QueryHeader `protobuf:"bytes,1,opt,name=header,proto3" json:"header,omitempty"`       // Standard info sent from client to node, including the signed payment, and what kind of response is requested (cost, state proof, both, or neither).
-	AccountID *AccountID   `protobuf:"bytes,2,opt,name=accountID,proto3" json:"accountID,omitempty"` // The account ID for which information is requested
+	Header *QueryHeader `protobuf:"bytes,1,opt,name=header,proto3" json:"header,omitempty"` // Standard info sent from client to node, including the signed payment, and what kind of response is requested (cost, state proof, both, or neither).
+	// Types that are assignable to BalanceSource:
+	//	*CryptoGetAccountBalanceQuery_AccountID
+	//	*CryptoGetAccountBalanceQuery_ContractID
+	BalanceSource isCryptoGetAccountBalanceQuery_BalanceSource `protobuf_oneof:"balanceSource"`
 }
 
 func (x *CryptoGetAccountBalanceQuery) Reset() {
@@ -69,13 +72,43 @@ func (x *CryptoGetAccountBalanceQuery) GetHeader() *QueryHeader {
 	return nil
 }
 
+func (m *CryptoGetAccountBalanceQuery) GetBalanceSource() isCryptoGetAccountBalanceQuery_BalanceSource {
+	if m != nil {
+		return m.BalanceSource
+	}
+	return nil
+}
+
 func (x *CryptoGetAccountBalanceQuery) GetAccountID() *AccountID {
-	if x != nil {
+	if x, ok := x.GetBalanceSource().(*CryptoGetAccountBalanceQuery_AccountID); ok {
 		return x.AccountID
 	}
 	return nil
 }
 
+func (x *CryptoGetAccountBalanceQuery) GetContractID() *ContractID {
+	if x, ok := x.GetBalanceSource().(*CryptoGetAccountBalanceQuery_ContractID); ok {
+		return x.ContractID
+	}
+	return nil
+}
+
+type isCryptoGetAccountBalanceQuery_BalanceSource interface {
+	isCryptoGetAccountBalanceQuery_BalanceSource()
+}
+
+type CryptoGetAccountBalanceQuery_AccountID struct {
+	AccountID *AccountID `protobuf:"bytes,2,opt,name=accountID,proto3,oneof"` // The account ID for which information is requested
+}
+
+type CryptoGetAccountBalanceQuery_ContractID struct {
+	ContractID *ContractID `protobuf:"bytes,3,opt,name=contractID,proto3,oneof"` // The account ID for which information is requested
+}
+
+func (*CryptoGetAccountBalanceQuery_AccountID) isCryptoGetAccountBalanceQuery_BalanceSource() {}
+
+func (*CryptoGetAccountBalanceQuery_ContractID) isCryptoGetAccountBalanceQuery_BalanceSource() {}
+
 // Response when the client sends the node CryptoGetAccountBalanceQuery
 type CryptoGetAccountBalanceResponse struct {
 	state         protoimpl.MessageState
@@ -150,30 +183,34 @@ var file_proto_CryptoGetAccountBalance_proto_rawDesc = []byte{
 	0x72, 0x6f, 0x74, 0x6f, 0x1a, 0x17, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x2f, 0x51, 0x75, 0x65, 0x72,
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+	0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
 }
 
 var (
@@ -194,18 +231,20 @@ var file_proto_CryptoGetAccountBalance_proto_goTypes = []interface{}{
 	(*CryptoGetAccountBalanceResponse)(nil), // 1: proto.CryptoGetAccountBalanceResponse
 	(*QueryHeader)(nil),                     // 2: proto.QueryHeader
 	(*AccountID)(nil),                       // 3: proto.AccountID
-	(*ResponseHeader)(nil),                  // 4: proto.ResponseHeader
+	(*ContractID)(nil),                      // 4: proto.ContractID
+	(*ResponseHeader)(nil),                  // 5: proto.ResponseHeader
 }
 var file_proto_CryptoGetAccountBalance_proto_depIdxs = []int32{
 	2, // 0: proto.CryptoGetAccountBalanceQuery.header:type_name -> proto.QueryHeader
 	3, // 1: proto.CryptoGetAccountBalanceQuery.accountID:type_name -> proto.AccountID
-	4, // 2: proto.CryptoGetAccountBalanceResponse.header:type_name -> proto.ResponseHeader
-	3, // 3: proto.CryptoGetAccountBalanceResponse.accountID:type_name -> proto.AccountID
-	4, // [4:4] is the sub-list for method output_type
-	4, // [4:4] is the sub-list for method input_type
-	4, // [4:4] is the sub-list for extension type_name
-	4, // [4:4] is the sub-list for extension extendee
-	0, // [0:4] is the sub-list for field type_name
+	4, // 2: proto.CryptoGetAccountBalanceQuery.contractID:type_name -> proto.ContractID
+	5, // 3: proto.CryptoGetAccountBalanceResponse.header:type_name -> proto.ResponseHeader
+	3, // 4: proto.CryptoGetAccountBalanceResponse.accountID:type_name -> proto.AccountID
+	5, // [5:5] is the sub-list for method output_type
+	5, // [5:5] is the sub-list for method input_type
+	5, // [5:5] is the sub-list for extension type_name
+	5, // [5:5] is the sub-list for extension extendee
+	0, // [0:5] is the sub-list for field type_name
 }
 
 func init() { file_proto_CryptoGetAccountBalance_proto_init() }
@@ -242,6 +281,10 @@ func file_proto_CryptoGetAccountBalance_proto_init() {
 			}
 		}
 	}
+	file_proto_CryptoGetAccountBalance_proto_msgTypes[0].OneofWrappers = []interface{}{
+		(*CryptoGetAccountBalanceQuery_AccountID)(nil),
+		(*CryptoGetAccountBalanceQuery_ContractID)(nil),
+	}
 	type x struct{}
 	out := protoimpl.TypeBuilder{
 		File: protoimpl.DescBuilder{
diff --git a/proto/CryptoGetAccountBalance.proto b/proto/CryptoGetAccountBalance.proto
index 258985058..7e1af77d5 100644
--- a/proto/CryptoGetAccountBalance.proto
+++ b/proto/CryptoGetAccountBalance.proto
@@ -14,7 +14,10 @@ option go_package = "github.com/hashgraph/hedera-sdk-go/proto";
 /* Get the balance of a cryptocurrency account. This returns only the balance, so it is a smaller and faster reply than CryptoGetInfo, which returns the balance plus additional information. */
 message CryptoGetAccountBalanceQuery {
     QueryHeader header = 1; // Standard info sent from client to node, including the signed payment, and what kind of response is requested (cost, state proof, both, or neither).
-    AccountID accountID = 2; // The account ID for which information is requested
+    oneof balanceSource {
+        AccountID accountID = 2; // The account ID for which information is requested
+        ContractID contractID = 3; // The account ID for which information is requested
+    }
 }
 
 /* Response when the client sends the node CryptoGetAccountBalanceQuery */
@@ -23,5 +26,3 @@ message CryptoGetAccountBalanceResponse {
     AccountID accountID = 2; // The account ID that is being described (this is useful with state proofs, for proving to a third party)
     uint64 balance = 3; // The current balance, in tinybars
 }
-
-