A few people seem to believe that working less than 35 years does not matter to social security benefits. That is not accurate - those years with zero earnings reduce your benefits:
If you stop work before you start receiving benefits and you have less than 35 years of earnings, your benefit amount is affected. We use a zero for each year without earnings when we calculate the amount of retirement benefits you are due. Years with no earnings reduces your retirement benefit amount.
https://www.ssa.gov/benefits/retirement/planner/stopwork.html
@MustacheAndaHalf , I realized we may be talking past each other, and I'm not sure my previous post helped so I wanted to try to be more clear because I think this is very important. Hopefully this post will make my position more clear so we can see if there really is a disagreement.
What I mean when I say that years of $0 earnings do NOT decrease benefits is the following:
Assuming a person has the required 40 credits and meets whatever (if any) qualifying criteria, the benefits they have earned can never decrease regardless of future earnings or lack thereof. For instance, if someone earns an inflation adjusted average of $100k for 10 years, they have earned a specific dollar amount when they qualify. They could go to the calculator and see exactly what that benefit is. If they never work again, their benefit will be the amount they earned and the $0 years will not cause their earned benefit to be docked or reduced in any way. Of course if they work more, their benefit will go up by the amount specified by the formula. But a benefit will not decrease due to a year of no earnings. This cannot happen (I'm ignoring cases where someone isn't eligible or does something illegal that might make them not qualify).
A way to think about it mathematically is to count each year as (Indexed earnings / 35). If you earn an indexed amount of $35k in one year, you've added $1,000 to your AIME. No zeros can ever decrease that. If you earn $70k in a year, that adds $2k to your AIME.
If someone earns $0 in any given year, their benefit *will* be lower than if they worked that year and paid more in to S.S (assuming that year is in their top 35). If by your statement that years with zero earnings will decrease your benefit you mean that if you earn more than zero your S.S. benefit will increase - I agree with that. I do not consider the lack of increase due to not working a decrease of any kind - it's just a lack of increase.
Hopefully that clarifies the point I was trying to make. I don't want anyone to come away from this and think that if they FIRE their benefits will decrease somehow - they will not, they just won't grow any more as they would if they kept working. And as has been pointed out, once you reach the second bendpoint any extra earnings do very little for your S.S. benefits.