I suspect that as unbelievable as this sounds, it might actually be true. There must be a ton of "repeated code" to handle all of the different states and rules. I'm guessing that they started with one huge bloated "template" and then wrote automatic code generation systems that just copied everything hundreds or even thousands of times.

They could very well now find themselves in a position where it is humanly impossible to untangle it all and make even the smallest changes. I'm calling it failed at this point.

Edit: Title was changed from: Healthcare.gov "contains about 500 million lines of software code". This comment reflects this fact which seems unbelievable, but if true, I feel would likely mean that it was mostly created by code generators that probably copied and ossified original errors and misconceptions to the point that it is no longer possible to fix. Its a total failure, the money is gone, but they'll keep throwing even more after it, until the tiny, disjointed systems they develop in the mean time as "temporary solutions" eventually become the "real" system.