According to a report present in the journal Health Affairs, in 2017 immigrants made up more than 18% of U.S. healthcare workers. There is currently a shortage of elderly and disabled workers, and limits on immigration would likely increase this shortage. It is predicted that the elderly population will have doubled by 2050, making this an even more pressing concern. According to Dr. John W. Rowe, in the future the U.S. may be in a similar position as Japan due to a projected low birth rate and large elderly population.
See "Immigrants play big role in caring for elderly and disabled in U.S", Linda Carroll, Reuters, June 5, 2019