Dr Jacobs trained in paediatrics across London until taking up a four year lecturer post (Honorary Senior Registrar) at the University of Manchester. During this period Dr Jacobs submitted an MD thesis on the psychology of children's eczema. He then undertook a three year fellowship at the Hospital for Sick Children, Toronto, Canada from1996-1999. During this period he obtained an MSc in Clinical Epidemiology with a thesis on measuring the severity of influenza in children (CARIFS).

Dr Jacobs then returned to the UK as a locum consultant paediatrician in the NHS and in the Royal Naval Hospital Gibraltar.

He was appointed consultant paediatrician to the Royal National Orthopaedic Hospital in 2002, and in 2004 he was appointed lead for the Paediatric Unit at the Royal National Orthopaedic Hospital, which included three consultant paediatricians and a child psychiatrist. In 2009, Dr Jacobs was appointed to the Trust Board at the Royal National Orthopaedic Hospital as Director of Children’s Services.