diff --git a/.gitattributes b/.gitattributes
index e1a82ed947a..06f1e4cc5d5 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -269,6 +269,7 @@ icu4j/src/com/ibm/icu/dev/tool/docs/icu4j342.api.gz -text
 icu4j/src/com/ibm/icu/dev/tool/docs/icu4j343.api.gz -text
 icu4j/src/com/ibm/icu/dev/tool/docs/icu4j36.api.gz -text
 icu4j/src/com/ibm/icu/dev/tool/docs/icu4j38.api.gz -text
+icu4j/src/com/ibm/icu/dev/tool/docs/icu4j381.api.gz -text
 icu4j/src/com/ibm/icu/dev/tool/tzu/icu.gif -text
 icu4j/src/com/ibm/icu/dev/tool/tzu/runicutzu.bat -text
 icu4j/src/com/ibm/icu/dev/tool/tzu/runicutzu.cmd -text
diff --git a/icu4j/build.xml b/icu4j/build.xml
index 5728b832265..577ad009059 100644
--- a/icu4j/build.xml
+++ b/icu4j/build.xml
@@ -832,7 +832,7 @@
   <target name="gatherapi" depends="tools" unless="before.java14" description="run API database generator tool">
     <javadoc classpath="${build.dir}" sourcepath="${src.dir}" packagenames="com.ibm.icu.lang,com.ibm.icu.math,com.ibm.icu.text,com.ibm.icu.util" source="1.4">
       <doclet name="com.ibm.icu.dev.tool.docs.GatherAPIData" path="${build.dir}">
-        <param name="-name" value="ICU4J ${icu4j.spec.version.string}" />
+        <param name="-name" value="ICU4J ${icu4j.impl.version.string}" />
         <param name="-output" value="${api.dir}/icu4j${icu4j.version.number}.api" />
         <param name="-internal" />
         <param name="-gzip" />
@@ -843,7 +843,7 @@
   <target name="gatherapi.with.version" depends="tools" unless="before.java14" description="run API database generator tool">
     <javadoc classpath="${build.dir}" sourcepath="${src.dir}" packagenames="com.ibm.icu.lang,com.ibm.icu.math,com.ibm.icu.text,com.ibm.icu.util" source="1.4">
       <doclet name="com.ibm.icu.dev.tool.docs.GatherAPIData" path="${build.dir}">
-        <param name="-name" value="ICU4J ${icu4j.spec.version.string}" />
+        <param name="-name" value="ICU4J ${icu4j.impl.version.string}" />
         <param name="-output" value="${api.dir}/icu4j${icu4j.version.number}.stver.api" />
         <param name="-internal" />
         <param name="-version" />
diff --git a/icu4j/src/com/ibm/icu/dev/tool/docs/icu4j381.api.gz b/icu4j/src/com/ibm/icu/dev/tool/docs/icu4j381.api.gz
new file mode 100644
index 00000000000..2b4b3026ce0
--- /dev/null
+++ b/icu4j/src/com/ibm/icu/dev/tool/docs/icu4j381.api.gz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:546dfc5bf2f2872d7804fbba61be67ee893b8a1ff082eb122f81bfd361a948b1
+size 30281