The current page says this:
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"Special extra earnings credits are granted for periods of active duty or active duty for training. Here's how the special extra earnings are credited on your record:
- From 1957 through 1977, you are credited with $300 in additional earnings for each calendar quarter in which you received active duty basic pay.
- From 1978 through 2001, for every $300 in active duty basic pay, you are credited with an additional $100 in earnings up to a maximum of $1,200 a year.
In January 2002, Public Law 107-117, the Defense Appropriations Act, stopped the special extra earnings that have been credited to military service personnel.
If you enlisted after September 7, 1980, and didn't complete at least 24 months of active duty or your full tour, you may not be able to receive the additional earnings.
NOTE: In all cases, we add the additional credit for military service to the earnings that we average over your working lifetime, not directly to your monthly benefit payment amount.
When you apply for benefits,
we automatically verify your military service. If your military service increases your benefit and we cannot get proof of your service, we will ask for your DD-214 or other proof of service before we process your application.
In all cases, we add military wage credits to your earnings, not directly to your monthly benefit payment."
Military service members who spent time on active duty (or active duty for training) from 1957 through 2001 may have extra Social Security wage credits added to their earnings record. Read to learn more about eligibility.
www.ssa.gov
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So, they verify it automatically, but might need your DD214 for extra documentation. Also, it's only added in to your annual earnings estimate (at a reduce rate), not to your monthly payout. Unless you have significant military earnings, it probably won't make a whole lot of difference.