Social Security recipients. Doctors who treat Medicare patients. Military pensioners. Companies with federal contracts. Government workers. Bond investors.
The reason: Treasury Secretary Jack Lew wouldn't have enough money to pay all the bills in full and on time.
Thursday is the working deadline for when the cash crunch begins, and though negotiators in Congress were making progress, as of late Monday, there was still no deal.
One of the biggest concern to global markets and investors is interest owed on the federal debt. Most experts assume that Treasury would do all it could to pay that first.