Significance of Social Security Life Claims?

James84179

I have several ancestors with unknown death dates, but have found hits in the "United States, Social Security Numerical Identification Files (NUMIDENT), 1936-2007" collection.

When I pull up the record in NARA / AAD, I see an entry code of "L" for Life Claim along with a date that is 75+ years after they were born, but before 1962, which is when I understand the Social Security death index started.

Is there any significance to do this date?