diff --git a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/ComplexGenericsInheritanceTest.kt b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/ComplexGenericsInheritanceTest.kt
index a736342..891ea37 100644
--- a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/ComplexGenericsInheritanceTest.kt
+++ b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/ComplexGenericsInheritanceTest.kt
@@ -20,7 +20,6 @@ package com.squareup.moshi.kotlin.codegen
 import com.google.common.truth.Truth.assertThat
 import com.squareup.moshi.JsonClass
 import com.squareup.moshi.Moshi
-import com.squareup.moshi.adapter
 import org.intellij.lang.annotations.Language
 import org.junit.Test
 
diff --git a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/DefaultConstructorTest.kt b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/DefaultConstructorTest.kt
index a211c7a..79b3bfb 100644
--- a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/DefaultConstructorTest.kt
+++ b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/DefaultConstructorTest.kt
@@ -17,7 +17,6 @@ package com.squareup.moshi.kotlin.codegen
 
 import com.squareup.moshi.JsonClass
 import com.squareup.moshi.Moshi
-import com.squareup.moshi.adapter
 import org.junit.Test
 
 class DefaultConstructorTest {
diff --git a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/GeneratedAdaptersTest.kt b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/GeneratedAdaptersTest.kt
index f42dff6..311a259 100644
--- a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/GeneratedAdaptersTest.kt
+++ b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/GeneratedAdaptersTest.kt
@@ -26,7 +26,6 @@ import com.squareup.moshi.JsonReader
 import com.squareup.moshi.JsonWriter
 import com.squareup.moshi.Moshi
 import com.squareup.moshi.ToJson
-import com.squareup.moshi.adapter
 import com.squareup.moshi.internal.NullSafeJsonAdapter
 import com.squareup.moshi.kotlin.codegen.annotation.UppercaseInAnnotationPackage
 import com.squareup.moshi.kotlin.codegen.annotation.UppercaseInAnnotationPackageJsonAdapter
diff --git a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MixingReflectAndCodeGen.kt b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MixingReflectAndCodeGen.kt
index 29510c9..61248c3 100644
--- a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MixingReflectAndCodeGen.kt
+++ b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MixingReflectAndCodeGen.kt
@@ -18,7 +18,6 @@ package com.squareup.moshi.kotlin.codegen
 import com.google.common.truth.Truth.assertThat
 import com.squareup.moshi.JsonClass
 import com.squareup.moshi.Moshi
-import com.squareup.moshi.adapter
 import com.squareup.moshi.kotlin.reflect.KotlinJsonAdapterFactory
 import org.junit.Test
 
diff --git a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MoshiKspTest.kt b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MoshiKspTest.kt
index 01884b4..4ef7b51 100644
--- a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MoshiKspTest.kt
+++ b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MoshiKspTest.kt
@@ -18,7 +18,6 @@ package com.squareup.moshi.kotlin.codegen
 import com.google.common.truth.Truth.assertThat
 import com.squareup.moshi.JsonClass
 import com.squareup.moshi.Moshi
-import com.squareup.moshi.adapter
 import org.junit.Test
 
 // Regression tests specific to Moshi-KSP
diff --git a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MultipleMasksTest.kt b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MultipleMasksTest.kt
index b7946fe..e1a4268 100644
--- a/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MultipleMasksTest.kt
+++ b/moshi-kotlin-tests/codegen-only/src/test/kotlin/com/squareup/moshi/kotlin/codegen/MultipleMasksTest.kt
@@ -17,7 +17,6 @@ package com.squareup.moshi.kotlin.codegen
 
 import com.squareup.moshi.JsonClass
 import com.squareup.moshi.Moshi
-import com.squareup.moshi.adapter
 import org.intellij.lang.annotations.Language
 import org.junit.Assert.assertEquals
 import org.junit.Test
diff --git a/moshi-kotlin-tests/src/test/kotlin/com/squareup/moshi/kotlin/DualKotlinTest.kt b/moshi-kotlin-tests/src/test/kotlin/com/squareup/moshi/kotlin/DualKotlinTest.kt
index de6e517..f3ca5af 100644
--- a/moshi-kotlin-tests/src/test/kotlin/com/squareup/moshi/kotlin/DualKotlinTest.kt
+++ b/moshi-kotlin-tests/src/test/kotlin/com/squareup/moshi/kotlin/DualKotlinTest.kt
@@ -23,7 +23,6 @@ import com.squareup.moshi.JsonDataException
 import com.squareup.moshi.Moshi
 import com.squareup.moshi.ToJson
 import com.squareup.moshi.Types
-import com.squareup.moshi.adapter
 import com.squareup.moshi.kotlin.reflect.KotlinJsonAdapterFactory
 import org.intellij.lang.annotations.Language
 import org.junit.Assert.fail
diff --git a/moshi-kotlin-tests/src/test/kotlin/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapterTest.kt b/moshi-kotlin-tests/src/test/kotlin/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapterTest.kt
index 295a61c..5543d48 100644
--- a/moshi-kotlin-tests/src/test/kotlin/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapterTest.kt
+++ b/moshi-kotlin-tests/src/test/kotlin/com/squareup/moshi/kotlin/reflect/KotlinJsonAdapterTest.kt
@@ -26,7 +26,6 @@ import com.squareup.moshi.JsonReader
 import com.squareup.moshi.JsonWriter
 import com.squareup.moshi.Moshi
 import com.squareup.moshi.ToJson
-import com.squareup.moshi.adapter
 import org.assertj.core.api.Assertions
 import org.junit.Assert.fail
 import org.junit.Test
diff --git a/moshi/src/main/java/com/squareup/moshi/-MoshiKotlinExtensions.kt b/moshi/src/main/java/com/squareup/moshi/-MoshiKotlinExtensions.kt
index e6db542..7878ef8 100644
--- a/moshi/src/main/java/com/squareup/moshi/-MoshiKotlinExtensions.kt
+++ b/moshi/src/main/java/com/squareup/moshi/-MoshiKotlinExtensions.kt
@@ -13,6 +13,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+@file:Suppress("EXTENSION_SHADOWED_BY_MEMBER")
+
 package com.squareup.moshi
 
 import com.squareup.moshi.internal.NonNullJsonAdapter
@@ -25,9 +27,11 @@ import kotlin.reflect.typeOf
  * @return a [JsonAdapter] for [T], creating it if necessary. Note that while nullability of [T]
  *         itself is handled, nested types (such as in generics) are not resolved.
  */
+@Deprecated("Use the Moshi instance version instead", level = DeprecationLevel.HIDDEN)
 @ExperimentalStdlibApi
 public inline fun <reified T> Moshi.adapter(): JsonAdapter<T> = adapter(typeOf<T>())
 
+@Deprecated("Use the Moshi instance version instead", level = DeprecationLevel.HIDDEN)
 @ExperimentalStdlibApi
 public inline fun <reified T> Moshi.Builder.addAdapter(adapter: JsonAdapter<T>): Moshi.Builder = add(typeOf<T>().javaType, adapter)
 
@@ -35,6 +39,7 @@ public inline fun <reified T> Moshi.Builder.addAdapter(adapter: JsonAdapter<T>):
  * @return a [JsonAdapter] for [ktype], creating it if necessary. Note that while nullability of
  *         [ktype] itself is handled, nested types (such as in generics) are not resolved.
  */
+@Deprecated("Use the Moshi instance version instead", level = DeprecationLevel.HIDDEN)
 @ExperimentalStdlibApi
 public fun <T> Moshi.adapter(ktype: KType): JsonAdapter<T> {
   val adapter = adapter<T>(ktype.javaType)
diff --git a/moshi/src/main/java/com/squareup/moshi/Moshi.kt b/moshi/src/main/java/com/squareup/moshi/Moshi.kt
index 0d6aeff..ba3af7f 100644
--- a/moshi/src/main/java/com/squareup/moshi/Moshi.kt
+++ b/moshi/src/main/java/com/squareup/moshi/Moshi.kt
@@ -17,6 +17,8 @@ package com.squareup.moshi
 
 import com.squareup.moshi.Types.createJsonQualifierImplementation
 import com.squareup.moshi.internal.NO_ANNOTATIONS
+import com.squareup.moshi.internal.NonNullJsonAdapter
+import com.squareup.moshi.internal.NullSafeJsonAdapter
 import com.squareup.moshi.internal.canonicalize
 import com.squareup.moshi.internal.isAnnotationPresent
 import com.squareup.moshi.internal.removeSubtypeWildcard
@@ -24,6 +26,9 @@ import com.squareup.moshi.internal.toStringWithAnnotations
 import com.squareup.moshi.internal.typesMatch
 import java.lang.reflect.Type
 import javax.annotation.CheckReturnValue
+import kotlin.reflect.KType
+import kotlin.reflect.javaType
+import kotlin.reflect.typeOf
 
 /**
  * Coordinates binding between JSON values and Java objects.
@@ -68,6 +73,32 @@ public class Moshi internal constructor(builder: Builder) {
   public fun <T> adapter(type: Type, annotations: Set<Annotation>): JsonAdapter<T> =
     adapter(type, annotations, fieldName = null)
 
+  /**
+   * @return a [JsonAdapter] for [T], creating it if necessary. Note that while nullability of [T]
+   *         itself is handled, nested types (such as in generics) are not resolved.
+   */
+  @CheckReturnValue
+  @ExperimentalStdlibApi
+  public inline fun <reified T> adapter(): JsonAdapter<T> = adapter(typeOf<T>())
+
+  /**
+   * @return a [JsonAdapter] for [ktype], creating it if necessary. Note that while nullability of
+   *         [ktype] itself is handled, nested types (such as in generics) are not resolved.
+   */
+  @CheckReturnValue
+  @ExperimentalStdlibApi
+  public fun <T> adapter(ktype: KType): JsonAdapter<T> {
+    val adapter = adapter<T>(ktype.javaType)
+    return if (adapter is NullSafeJsonAdapter || adapter is NonNullJsonAdapter) {
+      // TODO CR - Assume that these know what they're doing? Or should we defensively avoid wrapping for matching nullability?
+      adapter
+    } else if (ktype.isMarkedNullable) {
+      adapter.nullSafe()
+    } else {
+      adapter.nonNull()
+    }
+  }
+
   /**
    * @param fieldName An optional field name associated with this type. The field name is used as a
    * hint for better adapter lookup error messages for nested structures.
@@ -161,6 +192,10 @@ public class Moshi internal constructor(builder: Builder) {
     internal val factories = mutableListOf<JsonAdapter.Factory>()
     internal var lastOffset = 0
 
+    @CheckReturnValue
+    @ExperimentalStdlibApi
+    public inline fun <reified T> addAdapter(adapter: JsonAdapter<T>): Builder = add(typeOf<T>().javaType, adapter)
+
     public fun <T> add(type: Type, jsonAdapter: JsonAdapter<T>): Builder = apply {
       add(newAdapterFactory(type, jsonAdapter))
     }