AbstractBackgroundThe arrival of disease‐modifying treatments for Alzheimer’s disease (AD) creates a substantial challenge for health systems because of the large patient pool and a complex diagnostic pathway, and in particular, for those countries that already have comparatively low capacity to provide timely, accurate AD diagnostic services. We estimate how much NHS England would have to invest over 10 years to bring its memory assessment services infrastructure up to the average capacity of the other G7 countries and project the resulting changes in wait times for a disease‐modifying Alzheimer’s treatment.MethodDesk research and expert interviews for capacity and cost data. Markov model to estimate the effect of investment on wait times because of limited capacity for specialist visits and confirmatory biomarker testing.ResultEngland has the lowest number of MRI and PET scanners and the second lowest number of AD specialists of the G7 countries (Table 1). Closing this gap would require an estimated investment of ∼GBP 5.5 billion over 10 years, of which 9% would go toward acquisition of 126 PET and 1,196 MRI scanners including building modification, maintenance and IT equipment cost, and 91% to support operative costs (salaries, CSF assays, tracers, and facility use). On an annual basis, this number amounts to GBP 99 per capita and 3.1% of the overall NHS budget. Wait times in the diagnostic process to determine treatment eligibility would go from an average 58 months to 10 months by year 10 of the investment (Figures 1 and 2)ConclusionAs a result of a long‐standing underinvestment in health system infrastructure, wait times to receive an AD treatment would be substantial in England. Targeted investments aimed at increasing the NHS’ capacity to the average of the remaining G7 countries would decrease those wait times significantly. While the required investment is sizeable, the cost of inaction is equally so, since the disease would progress to more severe and costly stages while patients are held up on wait lists.