IntroductionThe NHS Long Term Workforce Plan aims for 10,000 physician associates (PAs, formerly physician assistants) by 2036/7. This article uses three modelling approaches to project the UK PA supply from a baseline of 2014–2021 through to 2038 to forecast the profession's growth. MethodsThe number of cClinically available PAs’ (cPAs; qualified PAs either working clinically or seeking clinical employment) was estimated using raw data from the 2014–2021 Faculty of Physician Associates censuses. This provided baseline data for all models (linear regression (LRM), exponential regression (ERM) and time-series forecast (TSFM)). Attrition, using data from other healthcare professions, was also modelled. ResultsR2 values together with authors’ judgement ruled the LRM more realistic than the ERM. The LRM projected up to 8,232 cPAs by 2038, although attrition reduced this significantly. The TSFM optimistically projected an upper limit (95% confidence interval) of 13,922 cPAs by 2038. DiscussionThis article permits a wider view of potential PA numbers, with broad agreement between the LRM and the TSFM. It appears that future PA demand will be met, but factors such as attrition could impede this. Attrition itself may be mitigated through adequate resourcing, appropriate support mechanisms, and the development of a career structure. Professional regulation and legislation will further support PAs to work to their potential, subject to appropriate patient safety measures.