ImportanceThe U.S. government has named post-acute sequelae of COVID-19 (longCOVID) as influential on disability rates. We previously showed that COVID-19 carries a medical/functional burden at 1  year, and that age and other risk factors of severe COVID-19 were not associated with increased longCOVID risk. Long-term longCOVID brain fog (BF) prevalence, risk factors and associated medical/functional factors are poorly understood, especially after mild SARS-CoV-2 infection.MethodsA retrospective observational cohort study was conducted at an urban tertiary-care hospital. Of 1,032 acute COVID-19 survivors from March 3–May 15, 2020, 633 were called, 530 responded (59.2 ± 16.3  years, 44.5% female, 51.5% non-White) about BF prevalence, other longCOVID, post-acute ED/hospital utilization, perceived health/social network, effort tolerance, disability.ResultsAt approximately 1-year, 31.9% (n= 169) experienced BF. Acute COVID-19 severity, age, and premorbid cardiopulmonary comorbidities did not differ between those with/without BF at 1  year. Patients with respiratory longCOVID had 54% higher risk of BF than those without respiratory longCOVID. BF associated with sleep disturbance (63% with BF vs.29% without BF,p< 0.0001), shortness of breath (46% vs.18%,p< 0.0001), weakness (49% vs.22%,p< 0.0001), dysosmia/dysgeusia (12% vs.5%,p< 0.004), activity limitations (p< 0.001), disability/leave (11% vs.3%,p< 0.0001), worsened perceived health since acute COVID-19 (66% vs.30%,p< 0.001) and social isolation (40% vs.29%,p< 0.02), despite no differences in premorbid comorbidities and age.Conclusions and relevanceA year after COVID-19 infection, BF persists in a third of patients. COVID-19 severity is not a predictive risk factor. BF associates with other longCOVID and independently associates with persistent debility.