Siegal joined the Times in 1960 as a copy boy. He eventually worked his way up to becoming a copy editor. In the 60s Siegal briefly worked at ABC News but later returned to the Times. In the 70s he went from editor to reporter and realized he enjoyed editing more than writing. He then asked to be reassigned to editing and was granted his request. He first worked on the foreign desk and later as the head of the news desk. Siegal was a part of the team that would turn the Pentagon Papers into news. In 1986 he became an assistant managing editor. Siegal is the lead editor of the Jayson Blair postmortem. During his time at the New York Times, Siegal served as the in-house authority on language, style, taste, professional ethics and practical newspapering. He co-authored the New York Times' stylebook and its ethics manual along with designing the first computer system in the newsroom. His last post at the Times was as standards editor. His responsibilities as a standards editor includes maintaining the newspaper's ethics, accuracy, fairness, and accountability. This position was created in 2003. Prior to working as a standards editor, he was the Times veteran assistant managing editor. He retired on May 12 2006 at the age of 66.