He remained at the Office of Public Works until 1927 when he was asked by Sean O'Casey to tour the United States of America with the Abbey Players for six months. That same morning he received a letter from the secretary of St Ultan's Children's Hospital in Charlemont Street, Dublin. Madeleine ffrench-Mullen (1880-1944) asked him to design a new wing for the hospital. After deliberation, it was decided that he should go on the tour with the Abbey while observing the latest trends in hospital design in the United States, and then return with ideas for St Ultan's. While he was there, Scott contemplated taking a job as an architect, taking up painting or acting full time. He was staying with his friend, the artist Patrick Tuohy (1884-1930) and was playing the lead role of Jack Clitheroe in the Broadway production of The Plough and the Stars. In the event he returned home to practice architecture from his father's front room. The new St Ultan's wing was opened in 1929 and was to be the first of many hospital commissions.
After an approach from Sean O'Casey and due to financial problems, Scott took up acting once again in 1929. This was the lead role of The New Gossoon by the Abbey Dramatist George Shiels (1886-1949) at the Apollo Theatre in London. Scott assumed the pseudonym of Wolfe Curran in an attempt to keep his acting career a secret from other architects. He was quite successful and acquired good reviews but the subsequent attention (from the Daily Express which exposed him as Michael Scott, an Irish architect) caused him to retire after three weeks. He never acted professionally again. The theatre was owned by J.B. Fegan who also owned another theatre in Oxford that needed renovation. Scott was interested in the job and took the part in the play on the understanding that he could have a drawing board in his dressing room.
In 1931 he joined forces with Norman D. Good to form Scott and Good, and they opened an office at 36 South Frederick Street, Dublin. Good was a successful businessman and a good draughtsman while Scott was responsible for most of the design work. The Irish Hospitals Committee had started the Hospital's Sweepstakes, a lottery in order to raise funds to fund the modernisation of the State's hospitals and as a result many hospitals were being constructed or extended. The Irish Government decided that a modern image was required for these hospitals and the Minister for Local Government and Public Health, Sean T. O'Kelly (1882-1966) compared Ireland to Finland, and suggested the work of Alvar Aalto (1898-1976) as examples. In a lecture to the Architectural Association of Ireland in 1933, O'Kelly stated:
We too in this country have room for men who will give to our peculiar problems the intense study they require, and help us build in a manner that will reflect credit on our country and generation. (Rothery, 1991, p. 146)
There was a keen interest in architecture from the Government ministers of the new state and they were often present at meetings of the AAI. The Hospital Sweepstakes building (Robinson Keefe, 1937) was itself a work of modern architecture with a long low front elevation with a glazed tower at one end. All of the new hospitals built in the 1930s were modern in style and the main beneficiaries of work were Vincent Kelly who was on the Sweepstakes Committee, T.J. Cullen (1880-1947), and Scott and Good, who rapidly gained reputations for designing hospitals and received one commission after another.