Treasury would mint a trillion dollar platinum coin, deposit it at the Federal Reserve and use those funds to make future payments. Just like that, the debt ceiling would be effectively eliminated.
Turns out, the Obama administration seriously considered minting the coin, according to the Huffington Post:
The Justice Department's Office of Legal Counsel, which functions as a sort of law firm for the president and provides him and executive branch agencies with authoritative legal advice, formally weighed in on the platinum coin option sometime since Obama took office, according to OLC's recent response to HuffPost's Freedom of Information Act (FOIA) request. While the letter acknowledged the existence of memos on the platinum coin option, OLC officials determined they were "not appropriate for discretionary release."
A 1996 law allows Treasury to mint platinum coins of any denomination. Supporters of the plan wanted Treasury to do just that, but in a large enough in value to enable the government to pay all of its bills.
In January, the White House shot down the proposal and the Federal Reserve has said that it would not accept the deposit of a trillion dollar coin. Nevertheless, many economic reporters supported the idea since breaching the debt ceiling would be catastrophic.
In October, Congress struck a last-minute deal to raise the debt-ceiling until mid-February. Treasury will be able to extend that deadline a bit by its use of extraordinary measures, but another potential debt limit fight is lurking next year. If