Coats represented Indiana in the U.S. House of Representatives from 1981 to 1989. He served as a senator from Indiana from 1989 to 1999, and again from 2011 to 2017. In the interim, he served as U.S. ambassador to Germany. Coats announced in March 2015 that he would not run for reelection in 2016.
During his time in the Senate, Coats was a member of the Senate Select Committee on Intelligence.
In March 2014, Coats was banned from entering Russia after President Barack Obama announced sanctions on high-level Russian officials and associates of Russian President Vladimir Putin. In retaliation for the sanctions, which were announced in response to Russia's move to annex Crimea, Coats and five other members of Congress (as well as three White House aides) were banned from the country.
A month later, Coats wandered into the wrong Senate subcommittee hearing.