diff --git a/IMPLEMENTATION_COVERAGE.md b/IMPLEMENTATION_COVERAGE.md
index f97963a7..7f6e8701 100644
--- a/IMPLEMENTATION_COVERAGE.md
+++ b/IMPLEMENTATION_COVERAGE.md
@@ -1699,17 +1699,17 @@
 - [ ] start_db_instance
 - [ ] stop_db_instance
 
-## acm - 50% implemented
-- [X] add_tags_to_certificate
-- [X] delete_certificate
-- [ ] describe_certificate
-- [X] get_certificate
-- [ ] import_certificate
-- [ ] list_certificates
-- [ ] list_tags_for_certificate
-- [X] remove_tags_from_certificate
-- [X] request_certificate
-- [ ] resend_validation_email
+## acm - 100% implemented
+- [x] add_tags_to_certificate
+- [x] delete_certificate
+- [x] describe_certificate
+- [x] get_certificate
+- [x] import_certificate
+- [x] list_certificates
+- [x] list_tags_for_certificate
+- [x] remove_tags_from_certificate
+- [x] request_certificate
+- [x] resend_validation_email
 
 ## elasticache - 0% implemented
 - [ ] add_tags_to_resource
diff --git a/tests/test_acm/test_acm.py b/tests/test_acm/test_acm.py
index db196964..ccac4818 100644
--- a/tests/test_acm/test_acm.py
+++ b/tests/test_acm/test_acm.py
@@ -4,6 +4,7 @@ import os
 import boto3
 from freezegun import freeze_time
 import sure  # noqa
+import uuid
 
 from botocore.exceptions import ClientError
 
@@ -281,11 +282,23 @@ def test_resend_validation_email_invalid():
 def test_request_certificate():
     client = boto3.client('acm', region_name='eu-central-1')
 
+    token = str(uuid.uuid4())
+
     resp = client.request_certificate(
         DomainName='google.com',
+        IdempotencyToken=token,
         SubjectAlternativeNames=['google.com', 'www.google.com', 'mail.google.com'],
     )
     resp.should.contain('CertificateArn')
+    arn = resp['CertificateArn']
+
+    resp = client.request_certificate(
+        DomainName='google.com',
+        IdempotencyToken=token,
+        SubjectAlternativeNames=['google.com', 'www.google.com', 'mail.google.com'],
+    )
+    resp['CertificateArn'].should.equal(arn)
+
 
 @mock_acm
 def test_request_certificate_no_san():