 "TS-19" garnered favorable reviews from most television critics. In his 8.5 out of 10 rating review, Eric Goldman of IGN wrote that the episode was an exceptional showing for the series, adding that it told "a compelling, intense story within its hour" albeit averting from the comics. As Michelle Kung of The Wall Street Journal wrote, "The first season of The Walking Dead doesn ’ t exactly end on an optimistic note, but our heroes are left driving into the unknown after escaping certain death at the CDC." Kurt Christenson of New York Daily News analyzed that "almost and everyone's still kind of in the dark", and Kelly stated that "TS-19" came to an "abrupt, explosive end". Salon journalist Simon Abrams concluded that the frenetic pace of The Walking Dead was relatable, while Paste television commentator Josh Jackson was keen of the character development in the episode as well as the varying political themes covered; "After six episodes, the characters are worth caring about. Despite occasional stilted monologues, quick tempers and unfortunate stereotypes, the few living souls in The Walking Dead are a bigger draw than the undead. The show has spent more time on topics like marriage, parenthood, unfaithfulness, loss, domestic violence, gender roles, small-scale politics, loyalty, kindness than it has with kill shots. By filling the world with zombies, Frank Darabont is able to explore the human condition under extreme circumstances." Entertainment Weekly writer Dan Snierson was entertained by "TS-19", and asserted that the conclusion "resonated over images of Rick & Co. U-turning into the great unknown, we got the sense that as long as they were alive, at least there was a chance of a tomorrow." Writing for the same publication, Jeff Jensen was intrigued at how producers approached the themes of the comics, and later noted that it was proof that they were using the comics as a route for thematic inspiration in lieu of a literal interpretation. For Los Angeles Times' Gina McIntyre, "Tonight's finale [...] did yield much insight, though, into the nature of the plague itself, in relative terms anyway."
