diff --git a/client/rest-high-level/src/main/java/org/elasticsearch/client/snapshotlifecycle/SnapshotLifecyclePolicy.java b/client/rest-high-level/src/main/java/org/elasticsearch/client/snapshotlifecycle/SnapshotLifecyclePolicy.java
index 8d8e78184ff..3fd357e2090 100644
--- a/client/rest-high-level/src/main/java/org/elasticsearch/client/snapshotlifecycle/SnapshotLifecyclePolicy.java
+++ b/client/rest-high-level/src/main/java/org/elasticsearch/client/snapshotlifecycle/SnapshotLifecyclePolicy.java
@@ -19,7 +19,7 @@
 
 package org.elasticsearch.client.snapshotlifecycle;
 
-import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
+import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.xcontent.ConstructingObjectParser;
@@ -43,8 +43,6 @@ public class SnapshotLifecyclePolicy implements ToXContentObject {
     private static final ParseField SCHEDULE = new ParseField("schedule");
     private static final ParseField REPOSITORY = new ParseField("repository");
     private static final ParseField CONFIG = new ParseField("config");
-    private static final IndexNameExpressionResolver.DateMathExpressionResolver DATE_MATH_RESOLVER =
-        new IndexNameExpressionResolver.DateMathExpressionResolver();
 
     @SuppressWarnings("unchecked")
     private static final ConstructingObjectParser<SnapshotLifecyclePolicy, String> PARSER =
@@ -61,11 +59,11 @@ public class SnapshotLifecyclePolicy implements ToXContentObject {
         PARSER.declareString(ConstructingObjectParser.constructorArg(), NAME);
         PARSER.declareString(ConstructingObjectParser.constructorArg(), SCHEDULE);
         PARSER.declareString(ConstructingObjectParser.constructorArg(), REPOSITORY);
-        PARSER.declareObject(ConstructingObjectParser.constructorArg(), (p, c) -> p.map(), CONFIG);
+        PARSER.declareObject(ConstructingObjectParser.optionalConstructorArg(), (p, c) -> p.map(), CONFIG);
     }
 
     public SnapshotLifecyclePolicy(final String id, final String name, final String schedule,
-                                   final String repository, Map<String, Object> configuration) {
+                                   final String repository, @Nullable Map<String, Object> configuration) {
         this.id = Objects.requireNonNull(id);
         this.name = name;
         this.schedule = schedule;
@@ -89,6 +87,7 @@ public class SnapshotLifecyclePolicy implements ToXContentObject {
         return this.repository;
     }
 
+    @Nullable
     public Map<String, Object> getConfig() {
         return this.configuration;
     }
@@ -103,7 +102,9 @@ public class SnapshotLifecyclePolicy implements ToXContentObject {
         builder.field(NAME.getPreferredName(), this.name);
         builder.field(SCHEDULE.getPreferredName(), this.schedule);
         builder.field(REPOSITORY.getPreferredName(), this.repository);
-        builder.field(CONFIG.getPreferredName(), this.configuration);
+        if (this.configuration != null) {
+            builder.field(CONFIG.getPreferredName(), this.configuration);
+        }
         builder.endObject();
         return builder;
     }
diff --git a/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/snapshotlifecycle/SnapshotLifecyclePolicy.java b/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/snapshotlifecycle/SnapshotLifecyclePolicy.java
index 5db1996a459..e1d760702bd 100644
--- a/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/snapshotlifecycle/SnapshotLifecyclePolicy.java
+++ b/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/snapshotlifecycle/SnapshotLifecyclePolicy.java
@@ -15,6 +15,7 @@ import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.Diffable;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver.Context;
+import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.UUIDs;
@@ -76,15 +77,15 @@ public class SnapshotLifecyclePolicy extends AbstractDiffable<SnapshotLifecycleP
         PARSER.declareString(ConstructingObjectParser.constructorArg(), NAME);
         PARSER.declareString(ConstructingObjectParser.constructorArg(), SCHEDULE);
         PARSER.declareString(ConstructingObjectParser.constructorArg(), REPOSITORY);
-        PARSER.declareObject(ConstructingObjectParser.constructorArg(), (p, c) -> p.map(), CONFIG);
+        PARSER.declareObject(ConstructingObjectParser.optionalConstructorArg(), (p, c) -> p.map(), CONFIG);
     }
 
     public SnapshotLifecyclePolicy(final String id, final String name, final String schedule,
-                                   final String repository, Map<String, Object> configuration) {
-        this.id = Objects.requireNonNull(id);
-        this.name = name;
-        this.schedule = schedule;
-        this.repository = repository;
+                                   final String repository, @Nullable Map<String, Object> configuration) {
+        this.id = Objects.requireNonNull(id, "policy id is required");
+        this.name = Objects.requireNonNull(name, "policy snapshot name is required");
+        this.schedule = Objects.requireNonNull(schedule, "policy schedule is required");
+        this.repository = Objects.requireNonNull(repository, "policy snapshot repository is required");
         this.configuration = configuration;
     }
 
@@ -112,6 +113,7 @@ public class SnapshotLifecyclePolicy extends AbstractDiffable<SnapshotLifecycleP
         return this.repository;
     }
 
+    @Nullable
     public Map<String, Object> getConfig() {
         return this.configuration;
     }
@@ -172,7 +174,7 @@ public class SnapshotLifecyclePolicy extends AbstractDiffable<SnapshotLifecycleP
             }
         }
 
-        if (configuration.containsKey(METADATA_FIELD_NAME)) {
+        if (configuration != null && configuration.containsKey(METADATA_FIELD_NAME)) {
             if (configuration.get(METADATA_FIELD_NAME) instanceof Map == false) {
                 err.addValidationError("invalid configuration." + METADATA_FIELD_NAME + " [" + configuration.get(METADATA_FIELD_NAME) +
                     "]: must be an object if present");
@@ -265,7 +267,9 @@ public class SnapshotLifecyclePolicy extends AbstractDiffable<SnapshotLifecycleP
         builder.field(NAME.getPreferredName(), this.name);
         builder.field(SCHEDULE.getPreferredName(), this.schedule);
         builder.field(REPOSITORY.getPreferredName(), this.repository);
-        builder.field(CONFIG.getPreferredName(), this.configuration);
+        if (this.configuration != null) {
+            builder.field(CONFIG.getPreferredName(), this.configuration);
+        }
         builder.endObject();
         return builder;
     }
diff --git a/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/snapshotlifecycle/history/SnapshotHistoryItem.java b/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/snapshotlifecycle/history/SnapshotHistoryItem.java
index 1c5a9ef751e..8120be9683f 100644
--- a/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/snapshotlifecycle/history/SnapshotHistoryItem.java
+++ b/x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/snapshotlifecycle/history/SnapshotHistoryItem.java
@@ -94,7 +94,7 @@ public class SnapshotHistoryItem implements Writeable, ToXContentObject {
         this.snapshotName = Objects.requireNonNull(snapshotName);
         this.operation = Objects.requireNonNull(operation);
         this.success = success;
-        this.snapshotConfiguration = Objects.requireNonNull(snapshotConfiguration);
+        this.snapshotConfiguration = snapshotConfiguration;
         this.errorDetails = errorDetails;
     }
 
diff --git a/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/snapshotlifecycle/history/SnapshotHistoryStoreTests.java b/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/snapshotlifecycle/history/SnapshotHistoryStoreTests.java
index 146af810fdd..43d069cfa0d 100644
--- a/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/snapshotlifecycle/history/SnapshotHistoryStoreTests.java
+++ b/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/snapshotlifecycle/history/SnapshotHistoryStoreTests.java
@@ -176,9 +176,12 @@ public class SnapshotHistoryStoreTests extends ESTestCase {
     }
 
     public static SnapshotLifecyclePolicy randomSnapshotLifecyclePolicy(String id) {
-        Map<String, Object> config = new HashMap<>();
-        for (int i = 0; i < randomIntBetween(2, 5); i++) {
-            config.put(randomAlphaOfLength(4), randomAlphaOfLength(4));
+        Map<String, Object> config = null;
+        if (randomBoolean()) {
+            config = new HashMap<>();
+            for (int i = 0; i < randomIntBetween(2, 5); i++) {
+                config.put(randomAlphaOfLength(4), randomAlphaOfLength(4));
+            }
         }
         return new SnapshotLifecyclePolicy(id,
             randomAlphaOfLength(4),
diff --git a/x-pack/plugin/ilm/src/test/java/org/elasticsearch/xpack/snapshotlifecycle/SnapshotLifecyclePolicyTests.java b/x-pack/plugin/ilm/src/test/java/org/elasticsearch/xpack/snapshotlifecycle/SnapshotLifecyclePolicyTests.java
index c2aac7120ab..1cc88bc4d75 100644
--- a/x-pack/plugin/ilm/src/test/java/org/elasticsearch/xpack/snapshotlifecycle/SnapshotLifecyclePolicyTests.java
+++ b/x-pack/plugin/ilm/src/test/java/org/elasticsearch/xpack/snapshotlifecycle/SnapshotLifecyclePolicyTests.java
@@ -131,9 +131,12 @@ public class SnapshotLifecyclePolicyTests extends AbstractSerializingTestCase<Sn
     }
 
     public static SnapshotLifecyclePolicy randomSnapshotLifecyclePolicy(String id) {
-        Map<String, Object> config = new HashMap<>();
-        for (int i = 0; i < randomIntBetween(2, 5); i++) {
-            config.put(randomAlphaOfLength(4), randomAlphaOfLength(4));
+        Map<String, Object> config = null;
+        if (randomBoolean()) {
+            config = new HashMap<>();
+            for (int i = 0; i < randomIntBetween(2, 5); i++) {
+                config.put(randomAlphaOfLength(4), randomAlphaOfLength(4));
+            }
         }
         return new SnapshotLifecyclePolicy(id,
             randomAlphaOfLength(4),