THE DISTRICT OF Columbia is unique among American cities in having a chief financial officer independent of the executive and legislative branches to keep watch over its municipal finances. For more than a decade, Natwar M. Gandhi has ably filled that role — saying no to excess spending and budget gimmickry — and the District enjoys a fiscal prudence unmatched by most cities. In just two months, his term expires. It is unclear whether he will be reappointed.

He should be. Mr. Gandhi’s tenure has not been without problems, but he has been a steadying, positive force in the city’s financial health. With probes dogging the mayor and the D.C. Council chairman, this is not the time to introduce further uncertainty into the District’s leadership.

A spokesman for Mayor Vincent C. Gray (D) said that no decision will be made until after budget deliberations are completed in May; Mr. Gandhi’s spokesman said that the CFO would have no comment. If recommended by the mayor for another five-year term, and if he accepts reappointment, Mr. Gandhi would have to be confirmed by the council, where it is by no means certain he would get the necessary seven votes. Indeed, there is even some suggestion, quietly being passed around, that the District has outgrown the need for an independent CFO and should, as other cities do, let the mayor control the fiscal officer.

This is a terrible idea. The District’s sorry history attests to what can come of cooked books. If anything, the success of the independent office should prompt other jurisdictions to follow suit.

Of late, Mr. Gandhi has come under attack for conservative revenue estimates that caused the city to tighten its belt only to have unexpected end-of-the-year surpluses. Projecting revenue is tricky, and, as former mayor Anthony A. Williams (D) told us, if mistakes are to be made, better to come in under rather than over with your projections. Mr. Williams appointed Mr. Gandhi during his first term in 2000, and under their joint leadership, along with that of then-Council Chairman Linda W. Cropp, the city was freed from oversight by a federal control board. “Unequivocally, positively” was the judgment of Mr. Williams, who will take over leadership of the Federal City Council, on whether the city would be well served by a third term for Mr. Gandhi.

To be sure, there are issues with Mr. Gandhi that can’t be overlooked. On his watch a mid-level manager was able to perpetuate the largest tax fraud in city history. He should have been more straightforward in the handling of the lottery contract. There’s a worry that his concern about image — witness his apparent use of private e-mail to avoid press attention — impedes getting to the bottom of problems. It will be important to hear from Mr. Gandhi on how he would approach another term.

But in his core responsibility Mr. Gandhi has served the city well. His smart management of the city’s books, his refusal to bend numbers to political pressure and his credibility with rating agencies on Wall Street have resulted in the District’s enviable financial situation. “The adult in the room” is how several people described Mr. Gandhi and the critical role he plays. Replacing him, and likely losing the team he has assembled, is too big a risk.