You are correct. While we are not cashing in these bonds yet, we will start doing so in 2019, right now SS still takes in more than expenditures, so we are adding to the fund, TEMPORARILY. "Trust Fund"---their words, not mine.

Interestingly, when you look at our 18.4 trillion debt, a little over 5 trillion is "interagency" debt---federal agencies that run at a deficit "borrow" money, thru T-bills, from those that generate a surplus---SS is the biggest example. I'm not really sure this should count, it's like saying a husband owes his wife $50. But since it is on the books, they count it. The next 6 trillion or so is owned by Americans---401K's, banks, insurance cos. This leaves about 7 trillion in "foreign debt". Of this 3.2 trillion is owned by China and Japan---which is in their interest to keep the dollar strong for export purposes. This leaves a little under 4 trillion spread around---however, two of the largest, in name, are "The Caribbean Trust" and Luxembourg. Both of these are thought to be fronts for hedge funds, so again, American money.

Now, you are again correct regarding the SS "fund"--when we start cashing in the T-bills in 2019 and SS runs at a deficit, we will have to auction off new T-bills to cover it. This will in effect transfer "interagency" debt of 2.9 trillion to the open market---be it foreign or domestic. But it will not increase the national debt, since this is already counted. But it will no longer be "all in the family"