This dataset contains retrospective estimates for the cost of informal care attributable to dementia in the United States of America from 2010 to 2019 and prospective cost estimates in 2030, 2040, and 2050 under both low and high growth scenarios. Retrospective estimates are provided for the US national level, each US state, and the District of Columbia. Prospective estimates are provided for the US national level only. Final estimates include both the replacement and forgone wage costs attributable to dementia per dementia case. The replacement cost model estimates how much it would cost to replace all informal caregiving with formal, paid caregivers. The forgone wage cost model estimates how much income is lost for informal caregivers by caring for a person living with dementia instead of working for a wage. All cost estimates are reported in 2019 United States dollars.