diff --git a/modules/grpc/common/grpc-grammar.ym b/modules/grpc/common/grpc-grammar.ym
index 53b8a81d6..421bf3ca7 100644
--- a/modules/grpc/common/grpc-grammar.ym
+++ b/modules/grpc/common/grpc-grammar.ym
@@ -52,6 +52,11 @@ GrpcClientCredentialsBuilderW *last_grpc_client_credentials_builder;
 %token KW_TARGET_SERVICE_ACCOUNTS
 %token KW_URL
 %token KW_ADC
+%token KW_SERVICE_ACCOUNT
+%token KW_TOKEN_VALIDITY_DURATION
+%token KW_AUDIENCE
+%token KW_SCOPE
+%token KW_KEY
 %token KW_COMPRESSION
 %token KW_BATCH_BYTES
 %token KW_CONCURRENT_REQUESTS
@@ -211,6 +216,7 @@ grpc_client_credentials_option
   | KW_TLS { grpc_client_credentials_builder_set_mode(last_grpc_client_credentials_builder, GCAM_TLS); } '(' grpc_client_credentials_builder_tls_options ')'
   | KW_ALTS { grpc_client_credentials_builder_set_mode(last_grpc_client_credentials_builder, GCAM_ALTS); } '(' grpc_client_credentials_builder_alts_options ')'
   | KW_ADC { grpc_client_credentials_builder_set_mode(last_grpc_client_credentials_builder, GCAM_ADC); } '(' ')'
+  | KW_SERVICE_ACCOUNT { grpc_client_credentials_builder_set_mode(last_grpc_client_credentials_builder, GCAM_SERVICE_ACCOUNT); } '(' grpc_client_credentials_builder_service_account_options ')'
   ;
 
 grpc_client_credentials_builder_tls_options
@@ -255,6 +261,16 @@ grpc_client_credentials_builder_alts_target_service_accounts
   |
   ;
 
+grpc_client_credentials_builder_service_account_options
+  : grpc_client_credentials_builder_service_account_option grpc_client_credentials_builder_service_account_options
+  |
+  ;
+
+grpc_client_credentials_builder_service_account_option
+  : KW_KEY '(' path_secret ')' { grpc_client_credentials_builder_service_account_set_key(last_grpc_client_credentials_builder, $3); free($3); }
+  | KW_TOKEN_VALIDITY_DURATION '(' nonnegative_integer64 ')' { grpc_client_credentials_builder_service_account_set_validity_duration(last_grpc_client_credentials_builder, $3); }
+  ;
+
 /* END_RULES */
 
 %%
diff --git a/modules/grpc/common/grpc-parser.h b/modules/grpc/common/grpc-parser.h
index 12b00dde3..3e4daf45c 100644
--- a/modules/grpc/common/grpc-parser.h
+++ b/modules/grpc/common/grpc-parser.h
@@ -35,6 +35,11 @@
   { "url",                       KW_URL }, \
   { "target_service_accounts",   KW_TARGET_SERVICE_ACCOUNTS }, \
   { "adc",                       KW_ADC }, \
+  { "service_account",           KW_SERVICE_ACCOUNT }, \
+  { "key",                       KW_KEY }, \
+  { "scope",                     KW_SCOPE }, \
+  { "audience",                  KW_AUDIENCE }, \
+  { "token_validity_duration",   KW_TOKEN_VALIDITY_DURATION }, \
   { "compression",               KW_COMPRESSION }, \
   { "batch_bytes",               KW_BATCH_BYTES }, \
   { "channel_args",              KW_CHANNEL_ARGS }, \