Alterman began his journalism career in 1983, freelancing originally for The Nation, The Washington Monthly, The New Republic, Harper’s, Le Monde diplomatique, and later, Vanity Fair, The New York Times Magazine, The New Yorker and The Atlantic Monthly, among others, while working as a senior fellow for the World Policy Institute in New York City and Washington, DC. Not long after, he became the Washington Correspondent for Mother Jones, and soon thereafter Rolling Stone, before returning to The Nation as a columnist in 1995. Alterman has also been a contributing editor to ELLE, and a regular columnist for Worth, the London Sunday Express and The Guardian.

Alterman was hired by MSNBC in 1996, both appearing as a commentator on the cable channel and writing a column posted on its website. In 2002 MSNBC engaged him to create the blog daily Altercation, one of the first blogs hosted by a mainstream media news organization. In September 2006, after a ten-year association, Alterman and MSNBC parted ways. Media Matters for America hired him as a Senior Fellow and agreed to host Altercation, effective September 18, 2006. Regular contributors to Altercation included sportswriter Charlie Pierce and historian and military officer Robert Bateman. On December 22, 2008 Alterman announced that Altercation would be moving to The Nation’s website in 2009, and would appear on a less regular basis than its previous Monday through Friday schedule. He has also worked as a history consultant for HBO Films.

Alterman was and remains a critic of Ralph Nader for Nader’s actions in the 2000 US presidential election, arguing that Nader is to blame for the election of George W. Bush because of vote splitting. He has called Nader “Bush’s Useful Idiot,” myopic, and a deluded megalomaniac. In the documentary An Unreasonable Man, he is quoted as saying:

Alterman’s first book was Sound & Fury: The Making of the Punditocracy, which won the 1992 George Orwell Award. Alterman wrote the book while studying for his doctorate in US history at Stanford University. Alterman’s other books include the national best-sellers What Liberal Media? The Truth About Bias and the News (2003, 2004), and The Book on Bush: How George W. (Mis)leads America (2004). The others include: Who Speaks for America? Why Democracy Matters in Foreign Policy, (1998), and the second edition of Sound & Fury (2000). His It Ain’t No Sin to be Glad You’re Alive: The Promise of Bruce Springsteen (1999, 2001), won the 1999 Stephen Crane Literary Award. In September 2004, Viking Press published When Presidents Lie|When Presidents Lie: A History of Official Deception and its Consequences – a version of his doctoral dissertation – on lies of major consequence told by presidents Franklin D. Roosevelt, John F. Kennedy, Lyndon Johnson, Ronald Reagan, and George W. Bush.

Alterman has taught journalism at both New York University and Columbia University. Since the fall of 2004, he has been a Professor of English at Brooklyn College, where he teaches courses in media and media history. In 2007 he was named a CUNY Distinguished Professor of English at Brooklyn College and Professor of Journalism at the CUNY Graduate School of Journalism. He is also a Senior Fellow at the Center for American Progress, and at the World Policy Institute in New York City.

His seventh book, published in 2008 by Viking was called Why We’re Liberals: A Political Handbook for Post-Bush America. Also in 2008, Alterman published a lengthy essay in The New Yorker on the decline of American newspapers and the future role of new media news sites. His eighth book, Kabuki Democracy: The System vs. Barack Obama, was published in early 2011. It was an extension of his lengthy article published in the summer of 2010 by The Nation. Alterman’s ninth book, The Cause: The Fight for American Liberalism from Franklin Roosevelt to Barack Obama (2012), is a history of postwar American liberalism co-authored with historian Kevin Mattson. Three years later, in 2015, his tenth book, Inequality in One City: Bill de Blasio and the New York Experiment was issued.

Alterman’s media criticism was the subject of two of his books. He writes a political column for The Nation and a weekly column for the Center for American Progress website. In contrast to conservative media commentators, Alterman argues that the press is biased against liberals rather than biased in their favor. He was called “the most honest and incisive media critic writing today” in the National Catholic Reporter, and the author of “the smartest and funniest political journal out there,” in The San Francisco Chronicle. In 2008, Alterman became a regular columnist for the Jewish magazine Moment, where he wrote regularly about Jewish issues. From 2009-2012, he was also a regular contributor to The Daily Beast.