Before I get to today's question, I must clarify some points about the Supplemental Security Income, or SSI, program.

Every single day, I get emails from people who confuse SSI with the Social Security program. SSI has absolutely nothing to do with Social Security, other than the fact that it happens to be managed by the Social Security Administration.

Everyone knows what Social Security is. You work, you pay Social Security taxes, and someday you retire and collect Social Security benefits. Or someday you become disabled (before age 66) and become entitled to Social Security disability benefits. Or someday you die and your widow, or widower, or minor children start getting Social Security survivor's benefits.

All of those benefits: retirement, disability, and survivors, are part of Social Security. Not one of those programs has anything to do with Supplemental Security Income.

SSI is a federal welfare program that pays a modest monthly benefit to very poor people who are either over age 65 or who are under 65 but disabled. You do not qualify for monthly SSI payments by working and paying taxes. You qualify simply by being a very poor U.S. citizen.

So please don't send me emails telling me you are getting SSI when you are actually getting Social Security disability benefits. And please don't go to the Social Security office and tell them you want to apply for SSI, when you actually want to file for Social Security retirement or disability benefits. And that is not simply a matter of semantics. I have given more than a few wrong answers to people because they incorrectly told me they were getting SSI. And I have heard from readers who intended to file for Social Security benefits, but instead told the Social Security office that they wanted to apply for SSI payments, and they ended up answering lots of welfare-oriented questions about their income and assets before someone realized the wrong application form was being used. So please remember that Social Security and SSI are completely different programs.

Q: My 68-year-old mother is very poor and disabled. She is living off of a $710-per-month SSI check. That's her only income. She has worked in the past and has 36 quarters of Social Security coverage. We are trying to talk her into taking any kind of job to get the extra four quarters she needs to qualify for Social Security retirement benefits. Can you guess how much extra she would get if she qualifies for Social Security in addition to her SSI?

A: I can tell you exactly how much extra she would get — $20. And you will have to decide if it really is worth it to push your almost 70-year-old mom out the door to get a job just so she can get an extra twenty bucks per month from the government!

Supplemental Security Income does exactly what its name implies: It supplements a person's income up to certain limits. Those limits depend primarily on your living situation. In other words: Do you rent or do you own a home? And do you live alone or do you share household expenses with others? The SSI limit also depends on the state where you live. There is a basic federal grant: currently $710 per month. But some states augment that federal payment with their own funds. Alas, your mom must live in one of the cheap states because she is just getting the federal payment.

So again, the way SSI works is that it supplements your mom's income up to that $710 level. As you said, she has no other income, so SSI just cuts her a monthly check for the full $710.

But if she had other income, they would simply reduce her SSI payment by a like amount — with a bit of a twist that I will explain in a minute. If your mom works and gets her "40 quarters" (the minimum amount necessary to qualify for monthly retirement benefits), she would probably end up getting a very small Social Security check. Let's say it would be $200 per month. The government would normally just take that off the top of her SSI payment, leaving her with only $510 in SSI benefits.

But the twist is that the rules say the government must disregard $20 of a person's income when figuring the SSI payment. So if your mom started getting a $200 Social Security check, they would count only $180 of that and apply it against her SSI payment; meaning she would get $530 from SSI.

In other words, if your mom does get a $200 Social Security check, she'd then start getting $530 from the SSI program, giving her a total monthly income of $730.

As I said at the beginning of my answer to your question, that is only $20 more than the $710 she is currently receiving. If it were my 68-year-old mom, I wouldn't make her flip burgers or greet customers at Wal-Mart for a year or so just to get her 40 quarters and eventually get an extra $20 from the government. Instead, I'd slip her the extra twenty bucks per month. Or how about being a nice guy and help mom out with a couple hundred per month? But if you do, make sure you don't tell the Social Security people about that. They might turn around and deduct that from her SSI check!