Also your last employer must be a railroad and there is a minimum number of years to get a RRB benefit. Otherwise your payments into RRB are transferred into Social Security.

I only worked for about four years for a railroad back in my college days. Social security doesn't count earnings before the age of 21 when determining your payment. I didn't have 35 years of work under Social Security as I was working overseas for twenty years. They average your 35 highest earning years after reaching 21 adjusted for inflation to calculate your payment.

However, the RRB deductions *were* counted in the Social Security calculation, even though I was under 21 when they were deducted from my salary. Sometimes the law is in your favor.