Turning credit card money into old-age money the taxman can't touch.

This is the long game, and it is a good one. If the points game is making you real money, you can take some of that money and grow it into a pile for when you are old that the government never gets to touch. One note before anything else: I am not your accountant, so treat this as the general idea and not personal advice.

Here is the whole thing in kid terms.

The piggy bank the taxman leaves alone

When you make money, a little of it has to go to the government. That is tax. But there is a special piggy bank for old-people money called a 401(k). Money you drop into that piggy bank does not get a tax bite taken out of it today.

Money from churning counts as your own little business. And your own little business gets its own special piggy bank, called a solo 401(k). This is the one that does the magic.

First, fill the easy piggy bank

If you have a normal job, you probably already have a 401(k) there. Fill that one up first. The solo 401(k) is for the extra money you want to tuck away on top, once the job one is full and if you can afford it.

Two doors to put money in

Your solo piggy bank has two doors.

The first is the boss door. You are the boss of your little business, so you can move up to about a fifth of your business profit into the piggy bank through this door. The nice part is that money stops counting as profit, so you pay less tax right now. The catch is that when you are old and take it out, the government takes its bite then instead.

The second is the extra door. You can also put in money you have already paid tax on. On its own that is just fine, nothing special. But now comes the trick.

The magic trick, called the mega backdoor

Right after you push money through that extra door, you flip it into a special version of the piggy bank called a Roth. Once your money is inside the Roth, something great happens. It grows for years and years, and when you are old and finally take it all out, you keep every single dollar, including everything it grew into. The taxman gets nothing.

Normally there are strict rules on how much you are allowed to put into a Roth. This little side move, the mega backdoor, lets you slip in far more than those rules usually allow. That is the whole reason people get excited about it.

And once the money is in there, you can grow it in almost anything, from boring safe funds to tiny slices of brand new companies. Peter Thiel famously did this with startup shares and turned a small Roth into billions, all of it tax-free.

A little free money for opening it

One more treat. When you open your solo 401(k), the government hands you a $500 thank-you each year for the first three years. That is free money just for doing the smart thing.

There are lots of little details hiding under all of this, and I left them out on purpose to keep it simple. If people want, I can go deeper on any piece later. And again, I am not your tax adviser, so talk to a real one before you actually do any of this.