The US Postal Service is likely to default on a major federal loan if it doesn't get some help from Congress—today, August 1.
The postal service owes roughly $5.5 billion in health care pre-payments.
Those payments were due last year, but Congress gave the postal service an additional nine months to come up with the money.
That hasn't happened.
Even if there is a default, the postmaster general says there will not be an interruption in mail delivery.