AFAIK the IRS has always been accepting of truncating / rounding values to full dollars and discarding cents. It's certainly been that way for the decades that I've been doing taxes.
...while financial institutions send reports to clients and the IRS that have the totals rounded only at the end, meaning the things that are supposed to match don't and can't.
Even though they are both in dollars, they are not consistent even to the nearest dollar.