Lexington, Va.

LOW-INCOME taxpayers are audited by the Internal Revenue Service more often than their higher-earning counterparts. The reason for this is not politics, as is commonly presumed; nor is it that these taxpayers must be watched closely for fraud. The problem, as many people found out this week, is that the low-income tax credit is wildly complex. For that reason, those who claim it are especially vulnerable to filing errors.

How complex is the credit? It's so complex that the I.R.S. publishes more than 50 pages of instructions. It's so complex that a Government Accountability Office report showed that taxpayers, tax-return preparers and I.R.S. staff members regularly made mistakes when calculating and administering it.

Because Congress and the I.R.S. have explained the high rate of audits for low-income earners as a fraud-prevention measure, these taxpayers have come under heightened scrutiny. But it is Congress that should be scrutinized for its failure to reduce the credit's complexity.

The trouble is that the fraud explanation resonates with the public far more deeply than the notion that those who claim the credit may be confused by the instructions. And that's because the stereotypes that apply to welfare recipients have come to be projected onto low-income taxpayers.

The credit didn't start out this way. Devised under President Gerald Ford as an alternative to welfare, the low-income tax credit was meant to reward low-wage workers with a tax credit that would offset income tax and social security liabilities. Over time, however, the credit entered the political lexicon as another name for welfare.

This transformation began when President Bill Clinton, in his January 1994 State of the Union address, greeted a recent expansion of the low-income tax credit as "real welfare reform." That's a Democratic president, equating a tax credit for the working poor with welfare reform.

Just as President Clinton was publicly expanding access to the low-income tax credit, Congress was busy ensuring that increasing numbers of those who claimed it would be audited. Indeed, the very year of President Clinton's address, Congress ended the I.R.S. program of auditing tax returns at random and stepped up the auditing of low-income taxpayers. Since 1998, Congress has appropriated more than $1 billion for audits of low-income taxpayers.

In 2003, when Congress decided to prevent 12 million low-income children from receiving the full benefit of the child tax credit, several Republican members of Congress likened the low-income tax credit to welfare.

Representative Spencer Bachus, a Republican from Alabama, stated that by increasing the child tax credit for low-income tax credit recipients, "we're turning the tax code into a welfare system." Congressman Rob Portman, a Republican from Ohio, stated that the low-income tax credit was "not a tax issue - it's a government transfer payment to people who do not pay income taxes."

A year later, the I.R.S. practically accepted the notion that the low-income tax credit was a form of welfare when it announced that certain low-income taxpayers would have to be pre-approved before they could receive their refunds. In other words, rather than receiving a refund after filling out a return like other taxpayers, these people will have to pre-qualify with a raft of paperwork proving their relationships with their children - as though they were applying for a governmental benefit.

Instead of spending our money subjecting low-income taxpayers to heightened scrutiny before and after they file their taxes, Congress should amend the law to eliminate the complexity. That would restore the low-income tax credit to its intended purpose - namely, rewarding the poor for working, not penalizing them for being poor.