WASHINGTON — The amount of money the IRS collects from audits and other reviews fell by nearly $3 billion this year as the agency shifted resources to make sure people got their economic stimulus checks.

Overall, collections dropped to $56.4 billion for the fiscal year that ended Sept. 30 — a 4.7 percent decrease from $59.2 billion collected in 2007, the agency said Monday.

It was the first year-to-year decrease in collections in a decade.

In addition to its regular duties, the IRS issued 117 million payments totaling more than $95 billion as part of the federal economic stimulus program this past spring.

"There was the challenge of doing stimulus and it was a tight budget year. Key enforcement resources actually declined slightly," said Linda Stiff, deputy commissioner for services and enforcement. "The other key point to note is that 2007 was a record-breaking enforcement year, a high-water mark by any and all definitions."

Stiff said that when comparing 2008 to 2006 and earlier years, "you still have a healthy increase and a good trend even though we weren't able to repeat the anomalies of 2007."

The number of audits of returns filed by individuals increased slightly this year. Those earning less than $200,000 had about a 1 percent chance of being audited. Those with incomes of more than $200,000 had about a 3 percent chance of being audited.

Meanwhile, taxpayers with incomes of more than $1 million had a 5.6 percent chance of being audited, a drop from 6.8 percent the year before. The number of audits for millionaires dropped even though their ranks increased by nearly 54,000. Sit-down audits with those making more than $1 million remained relatively flat. The big drop occurred with reviews conducted through correspondence.

Officials attributed part of that decline to staffing. They noted that the agency had about 465 fewer agents and officers in key enforcement occupations compared to the year before.

On the business front, there was little change in the audit rates for 2008 compared to the previous year. The rates increased slightly for companies with more than $50 million in assets.

Stiff said the agency would continue to focus on larger corporations and international transactions next year. She said the struggling economy means the IRS will have to strike the right balance between helping taxpayers get through poor economic conditions while also helping them meet their tax obligations.

Customer satisfaction rates remained relatively high, though they dropped from 94 to 93 percent. But customers calling the agency's toll-free line probably weren't so pleased. About 53 percent of callers seeking information were able to get through, a steep fall from previous years, when more than 80 percent of callers got through.