There has been an ongoing dispute between the SSA and its OIG about what to do about millions of dormant accounts for which SSA lacks a date of death. [0] SSA OIG views these accounts as a risk and wants them marked as presumed dead. SSA argues that it is unnecessary, that it would cost millions in administrative and IT costs for little real benefit, that there is a risk of accidentally marking living people as dead, and disagrees that it is a fraud risk since no benefits have been paid to these dormant accounts for many decades, and any attempt to “reactivate” one of them would be flagged as an anomaly and investigated as potential fraud. It would not surprise me if Musk’s claims of “150 year old social security recipients” turn out to be a distortion of this pre-existing debate. The distortion is in presenting these accounts as active cases of fraud, since the vast majority of them haven’t received benefits in decades, or never claimed them to begin with - they are mostly long-dead people who were registered with the SSA in the first few decades of its existence, but for whatever reason their death was never reported to the SSA (the processes for doing so were less effective decades ago and so the further back you go, the more deaths were “missed”)

[0] see e.g. https://oig.ssa.gov/assets/uploads/a-06-21-51022.pdf