Abstract: To discourage firms from buying and selling tax deductions, Section 382 of the tax code limits the ability of one firm to use the ‘‘net operating losses’’ (NOLs) of another firm that it acquires. Under the Troubled Asset Relief Program, the U.S. Treasury lent a large amount of money to General Motors. In bankruptcy, it then transformed the debt into stock. GM did not make many cars anyone wanted to buy, but it did have $45 billion in NOLs. Unfortunately for the Treasury, if it now sold the stock it acquired in bankruptcy, it would trigger Sec. 382. Foreseeing this, the market would pay much less for its stock in GM. Treasury solved this problem by issuing a series of notices in which it announced that the law did not apply to itself. Sec. 382 says that the NOL limits apply when a firm’s ownership changes. That rule would not apply to any firm bought with TARP funds, declared Treasury. Notwithstanding the straightforward and all-inclusive statutory language, GM could use its NOLs in full after Treasury sold out. The Treasury issued similar notices about Citigroup and AIG. Treasury had no legal or economic justification for any of these notices, but the press did not notice. Precisely because they involved such arcane provisions of the corporate tax code, they largely escaped public attention. The losses to the public fisc were not minor — they cost the country billions of dollars in tax revenue. That the effect could be so large and yet so hidden illustrates the risk involved in this kind of tax manipulation. The more difficult the tax rule, the more easily the government can use it to hide the cost of its policies and subsidize favored groups. We suggest that Congress give its members standing to challenge unlegislated tax law changes in court.