Estimating the costs of poor health literacy is clearly a complex area which requires some assumptions to be made. US research suggests that the annual cost of poor health literacy is 3–5% of the health budget.86 Based on these estimates, the cost of poor health literacy in England could be £2.95–4.92bn (based on the NHS England budget for 2014-15 being £98.4bn).30 However, it is difficult to accurately transfer US cost implication findings to the English health system.