Again there will be no default unless the President and Congress does something illegal
The default in April 1979, ended up costing taxpayers hundreds of billions of dollars. The Treasury Department blamed it on a crush of paperwork partly caused by lawmakers who — this will sound familiar — bickered too long before raising the nation's debt limit. It was lawmakers determined to attach a strong balanced budget amendment to the bill.
They finally relented, the day before Social Security checks were expected to start bouncing. The tumult contributed to Treasury's failure to redeem $122 million in maturing T-bills, touted as one of the world's safest investments.
Many bond holders were forced to join & file a class-action lawsuit against thr US treasury. Some investors that April and May waited more than a week for their money. Treasury blamed problems with its newfangled word-processing equipment. The system was stressed, officials said, when the booming popularity of T-bills
collided with the last-minute debt ceiling increase from Congress.
Investors called it a "default" and sued for interest to cover the gap. Treasury called it a "delay." It ushered in an 8% rise in interest rates that took 8 years to return to previous level. That cost taxpayers hundreds of billions of dollars.