President Trump — with, from left, Vice President Pence, White House Chief of Staff Reince Priebus, head of the White House Trade Council Peter Navarro and senior adviser Jared Kushner — signs an executive order that places a hiring freeze on non-military federal workers on Jan. 23. (Kevin Lamarque/Reuters)

Shortages of employees already contribute to putting some federal programs at high risk, and the hiring freeze will make it “more difficult” to address that problem, the government’s top auditor said Wednesday.

“We’ve looked at hiring freezes in the past by prior administrations and they haven’t proven to be effective in reducing costs and they cause some problems if they’re in effect for a long period of time,” Comptroller General Gene Dodaro told a House Oversight and Government Reform Committee hearing.

Dodaro heads the Government Accountability Office, which released its biennial description Wednesday of federal programs at high risk of mismanagement, fraud, waste and abuse.

“We know there are already skill gaps … cybersecurity, acquisition workforce, oil and gas management, petroleum engineers. A number of areas on our high-risk list have human capital [aspects] — nurses at the VA [Veterans Affairs], a lot of areas. There likely will be emerging skill gaps and you’re going to have a lot of people retiring,” he said.

Preparing for such turnover, and recruiting and retaining employees in key occupations, is itself at high risk; the GAO has pointed to that challenge in “strategic human capital management” since 2001.

The freeze, ordered in the early days of the Trump administration, allows for exceptions, primarily for jobs deemed vital for national security or public safety reasons. Agencies could justify continued hiring from some of the occupations Dodaro listed.

Meanwhile, unlike some prior freezes that the GAO said actually raised costs, the current freeze bars federal agencies from adding contractors to make up for the work as employees leave.

Further, the two central agencies overseeing the federal workforce, the Office of Personnel Management and the Office of Management and Budget, are to produce within 90 days a long-range plan to reduce the workforce by attrition. Such a plan could include an extended freeze, although possibly on different terms.

“I think a lot of it will depend on what kind of plan they come up with at the end of this temporary hiring freeze. But a sustained hiring freeze is not the best way. It’s better to do it through a budget or workforce plan,” Dodaro said.

“If you want to reduce the number of federal employees, in my opinion, you have to reduce the functions that those employees are doing. If you don’t reduce federal programs, eliminate programs, reduce things, or find some other way to do it, if you just eliminate the employees but keep all the functions there you’re going to have a problem,” he added.

Groups representing federal mid-level managers and senior executives made similar arguments at a Senate hearing last week about how the freeze could affect services to the public.