Rationale: shared symptoms and genetic architecture between COVID-19 and lung fibrosis suggests SARS-CoV-2 infection may lead to progressive lung damage.Objectives: the UKILD Post-COVID study interim analysis was planned to estimate the prevalence of residual lung abnormalities in people hospitalised with COVID-19 based on risk strata.Methods: the Post-HOSPitalisation COVID Study (PHOSP-COVID) was used for capture of routine and research follow-up within 240 days from discharge. Thoracic CTs were linked by PHOSP-COVID identifiers and scored for percentage involvement of residual abnormalities (ground glass opacities and reticulations). Risk factors in linked CT were estimated with Bayesian binomial regression and used to generate risk strata. Numbers of cases within strata were used to estimate post-hospitalisation prevalence using Bayesian binomial distributions. Sensitivity was performed in research follow-up participants.Measurements and Main Results: the interim cohort comprised 3700 people. Of 209 linked CTs (median 119 days, interquartile range 83-155), 164 people (79.6%) had >10% involvement of residual lung abnormalities. Major risk factors included abnormal chest X-ray (RR 1·21 95%CrI 1·05; 1·40), percent predicted DLcoConclusions: prevalence of residual lung abnormalities were estimated in up to 11% of people discharged following COVID-19 related hospitalisation. Health services should monitor at-risk individuals to elucidate long term functional implications.