Smaller budgets have hurt the Internal Revenue Service’s performance, according to a new government report.

“IRS has absorbed budget cuts since fiscal year 2010, and the resulting imbalance between service and demand has adversely affected operations,” concluded the report from the Governmental Accountability Office, which was delivered to the heads of various congressional committees considering the IRS’s fiscal 2015 budget request.

The full report, which was released on Monday, points out that IRS appropriations for fiscal 2014 are below the levels for fiscal 2010 ($11.199 billion, versus $11.523 billion), and that the agency has lost the equivalent of 8,000 employees since 2009.

These cuts have, among other things, led the IRS to delay two IT projects and substantially reduce employee training. It has also led to service issues, the report suggested, including a near-doubling of waiting times on IRS phone lines since fiscal year 2009 — from 8.8 minutes to 16.8 minutes as of mid-March 2014.

The IRS is requesting a budget of $12.5 billion for fiscal 2015, an increase of 10.5 percent in funding and 8.3 percent in staffing, in part to improve enforcement and to handle some of the additional mandates placed on the service, such as those related to the implementation of the Affordable Care Act.

While the GAO report did say that budget cuts had hurt the IRS, it also said that extra money was not the only solution: The GAO has an open list of ways the IRS could improve its performance, such as eliminating duplicate programs and developing a long-term plan to improve its Web services.