Corcoran was first involved with the Colchester United first team after being named on the bench for a League One game against Millwall on 31 March 2009, while he was in the second year of his scholarship. He made his debut for Colchester after coming on as an 89th minute substitute in a 2–0 victory over Hereford United. Following this match, he drew praise from manager Paul Lambert, who said he hoped Corcoran would become a regular player in the team.
On 4 December 2009 he joined Wealdstone on a month’s loan. Which was later extended by a further month. On 18 May 2010 Corcoran was released by Colchester. However after John Ward was announced as Colchester manager on 31 May 2010 Corcoran was offered a new 1-year contract. On 10 March 2011 Corcoran was loaned out to Isthmian League Premier Division side Lowestoft Town for one month. He was recalled on 6 April.
On 28 April Colchester announced that he would be one of three players who would be released at the end of the season. He signed for Chelmsford City before the start of the 2011–12 season.
On 20 November 2012, video footage of Corcoran’s free kick in a game against Hayes & Yeading United F.C. in the Conference South went viral as he slipped before kicking the ball, allowing Hayes and Yeading possession and leading them to score and win the game 3–0. It was described in media coverage as the “worst free kick ever”. Corcoran took the coverage in good humour, claiming on his Twitter account that the free kick was a “stinker” and that he was a “youtube sensation for all the wrong reasons”.
Corcoran was released by Chelmsford City on 2 February 2013. Within a fortnight he signed for Hayes & Yeading United, the very team against which he had suffered his free kick misfortune. He made his debut on 16 February 2013 against Farnborough FC, having been substituted on for Pelé (footballer born 1978). Hayes and Yeading lost the match 4–1.
On January 31, 2014 it was announced that Corcoran had been training with St Albans City for the past 8 weeks in a bid to regain fitness but a broken foot meant his debut had to wait until March. He became a regular in the team, and could often be seen controlling games in the heart of midfield. Sam then left the Saints at the end of the 2015/2016 season to join local rivals, Hemel Hempstead Town. Despite initially taking on the role as club captain, Sam lost his place in the team and was released from his contract in January 2017.
Sam re-signed for the Saints in February 2017. He was then released by the club in March 2017.