Annen returned to the Bundestag at the 2013 election, regaining the Hamburg Eimsbüttel district from the CDU. He soon re-entered the leadership of the Parliamentary Left in 2014. He also serves as chairman of the Parliamentary Friendship Group for Relations with the States of South Asia, including Afghanistan, Bangladesh, Bhutan, Maldives, Nepal, Pakistan, and Sri Lanka. Between 2014 and 2015, he represented his parliamentary group in a crossparty committee headed by former defense minister Volker Rühe to review the country's parliamentary rules on military deployments.