diff --git a/plans/add_compiler.pp b/plans/add_compiler.pp
new file mode 100644
index 00000000..d181f5c7
--- /dev/null
+++ b/plans/add_compiler.pp
@@ -0,0 +1,68 @@
+# @summary Add a new compiler to a PE architecture or replace an existing one with new configuration.
+# @param avail_group_letter _ Either A or B; whichever of the two letter designations the compiler is being assigned to
+# @param compiler_fqdn _ The FQDN and certname of the new compiler
+# @param dns_alt_names _ A comma_separated list of DNS alt names for the compiler
+# @param primary_server_fqdn _ The FQDN and certname of the primary Puppet server
+# @param postgresql_server_fqdn _ The FQDN and certname of the PE-PostgreSQL server with availability group $avail_group_letter
+plan peadm::add_compiler(
+  String[1] $avail_group_letter,
+  Peadm::SingleTargetSpec $compiler_fqdn,
+  Optional[String[1]] $dns_alt_names = undef,
+  Peadm::SingleTargetSpec $primary_server_fqdn,
+  Peadm::SingleTargetSpec $postgresql_server_fqdn,
+){
+  # Stop puppet.service
+  run_command('systemctl stop puppet.service', $postgresql_server_fqdn)
+
+  # Add the following two lines to /opt/puppetlabs/server/data/postgresql/11/data/pg_ident.conf
+  # 
+  # pe-puppetdb-pe-puppetdb-map <new-compiler-fqdn> pe-puppetdb
+  # pe-puppetdb-pe-puppetdb-migrator-map <new-compiler-fqdn> pe-puppetdb-migrator
+
+  apply($postgresql_server_fqdn) {
+    file_line { 'pe-puppetdb-pe-puppetdb-map':
+      path => '/opt/puppetlabs/server/data/postgresql/11/data/pg_ident.conf',
+      line => "pe-puppetdb-pe-puppetdb-map ${compiler_fqdn} pe-puppetdb",
+    }
+    file_line { 'pe-puppetdb-pe-puppetdb-migrator-map':
+      path => '/opt/puppetlabs/server/data/postgresql/11/data/pg_ident.conf',
+      line => "pe-puppetdb-pe-puppetdb-migrator-map ${compiler_fqdn} pe-puppetdb-migrator",
+    }
+  }
+
+  # Reload pe-postgresql.service
+  run_command('systemctl reload pe-postgresql.service', $postgresql_server_fqdn)
+
+  # Install the puppet agent making sure to specify an availability group letter, A or B, as an extension request.
+  $dns_alt_names_flag = $dns_alt_names? {
+    undef   => [],
+    default => "main:dns_alt_names=${dns_alt_names}",
+  }
+
+  run_task('peadm::agent_install', $compiler_fqdn,
+    server        => $primary_server_fqdn,
+    install_flags => $dns_alt_names_flag + [
+      "extension_requests:${peadm::oid('pp_auth_role')}=pe_compiler",
+      "extension_requests:${peadm::oid('peadm_availability_group')}=${avail_group_letter}",
+      "main:certname=${compiler_fqdn}",
+    ],
+  )
+
+  # If necessary, manually submit a CSR
+  # run_task('peadm::submit_csr', $compiler_fqdn)
+  # On primary-server-fqdn, if necessary, sign the certificate request
+  run_task('peadm::sign_csr', $primary_server_fqdn, { 'certnames' => [$compiler_fqdn] } )
+
+  # On <compiler-fqdn>, run the puppet agent 
+  run_task('peadm::puppet_runonce', $compiler_fqdn)
+
+  # On <postgresql-server-fqdn>:
+  # Run the puppet agent
+  run_task('peadm::puppet_runonce', $postgresql_server_fqdn)
+
+  # Start puppet.service
+  run_command('systemctl start puppet.service', $postgresql_server_fqdn)
+
+  return("Adding or replacing compiler ${compiler_fqdn} succeeded.")
+
+}