Back in 2005, Congress passed a tax law that included a really tough provision. It requires agencies to withhold three percent of contractors’ payments against their future tax bills. The day of reckoning has come, and IRS issued a final rule yesterday. The good news is, agencies have a year to figure out how to deal with this controversial rule. The bad news is, the work starts now. Steve Charles, executive vice president of the immixGroup, a company that represents hundreds of contractors selling to the federal government, explains what’s ahead and what’s at stake.