500 million lines of code is either a number somebody pulled out of thin air, or one that some MSM reporter has botched up. I am a computer programmer by profession, and this is my not so humble opinion.
Relax.. Only 5 MILLION lines of code need to be rewritten though.
I did hear one computer guy saying it would take a year just to fix the front end of this mess, codes etc.,......let alone what happens when you get sick and actually have to submit a claim...not to mention all the security issues...