[Also available on Facebook.]
One event that can end the financial support obligations created by the Form I-864, Affidavit of Support, is if the sponsored immigrant (typically a spouse) has worked, or can be credited with, 40 qualifying quarters. This is the equivalent of 10 years worth of work.
According to the Social Security Administration, here is how they calculate work credits:
We base Social Security credits on the amount of your earnings. We use your earnings and work history to determine your eligibility for retirement or disability benefits or your family’s eligibility for survivors benefits when you die. In 2022, you receive one credit for each $1,510 of earnings, up to the maximum of four credits per year.