He could touch social security/Medicare or Medicaid by purging the rolls of the deceased
https://www.foxnews.com/politics/elon-musk-says-millions-soc...
Elon Musk says millions in Social Security database are between ages of 100 and 159. If they purged millions of 120-160 year olds from the social security database and limited it to only people who were currently alive they could make progress