copyright 2009, The Washngton Post WASHINGTON -- The federal government needs to hire more than 270,000 workers for 'mission-critical' jobs over the next three years, a surge prompted in part by the large number of baby-boomer federal workers reaching retirement age, according to the results of a government-wide survey being released Thursday. The numbers also reflect the Obama administration's intent to take on several enormous challenges, including the repair of the financial sector, fighting two wars, and addressing climate change. 'It has to win the war for talent in order to win the multiple wars it's fighting for the American people,' said Max Stier, president and chief executive of the Partnership for Public Service, the think tank that conducted the survey of 35 federal agencies, representing nearly 99 percent of the federal workforce. Despite its comprehensive scope, the survey is necessarily imprecise about certain questions in looking so far into the future. The number of hires would be affected, for example, by federal workers deciding to delay their retirement, the government continuing to rely on private contractors to handle some of these jobs, and Congress balking at the price tag of adding new workers to the federal payroll. Nevertheless, the survey makes clear that the majority of new hires will be needed in five broad fields -- medical, security, law enforcement, legal and administrative. Mission-critical jobs are those positions identified by the agencies as being essential for carrying out their services. The study estimates that the federal government will need to hire nearly 600,000 people for all positions over President Obama's four years -- increasing the current workforce by nearly one-third. The medical and public health area is most in need of hires, according to the study. Stier described the Veterans Administration as a 'dramatic example' of an agency with pressing needs, as a result of the ongoing wars in Iraq and Afghanistan. The VA, according to the report, will need more than 48,000 hires over the next three years, including 19,000 nurses and 8,500 physicians. Intelligence agencies expect to hire 5,500 people in the next year and 'in the same order of magnitude' over the following two years, according to Ronald Sanders, chief human capital officer for the Office of the Director of National Intelligence. Such agencies include the Central Intelligence Agency and the National Security Agency. 'It's a combination of how much turnover we expect and how much growth we expect in our budget,' Sanders said. The nation's unsettled economy and high unemployment rate may ease the government's task, as workers turn to the federal sector for job security and good benefits. But Stier said many federal agencies will have to fight to attract top talent, particularly in fields in which government cannot compete with private-sector salaries. 'Most are going to see extreme competition with the private sector,' Stier said. This could be especially true in fields such as medical, legal and information technology, he said. OPM Director John Berry was unavailable to comment on the report, according to a spokesperson. The survey results are to be posted Thursday at www.wherethejobsare.org, according to the partnership. Staff writers Joe Davidson and Ed O'Keefe contributed to this report. 