As the University’s annual budget-planning memo gets pushed back another week, department heads are left waiting and wondering how much of Yale’s $100 million budget gap will fall on them.

Until they receive the memo — which is usually sent around Christmas but has been delayed this year — department heads can only guess at whether the University’s budget cuts will lead to minor inconveniences or drastic cuts.

A December letter from University President Richard Levin announcing a precipitous decline in Yale’s endowment pushed the memo’s release into the new year, and the upcoming meeting of the Yale Corporation — the University’s highest governing body — has delayed it further.

Provost Peter Salovey said the extra time will allow the administration to see how the economic crisis continues to unfold, lessening the chance that the budget guidelines will have to be revised later. But yet another week in limbo has left department managers waiting for their instructions with some confusion and anxiety about what to expect and what to do about next year’s budget cuts.

“This is all uncharted territory for us,” said Millicent Marcus, chair of the Italian Department. “We don’t have the budget [memo] yet, so we have no idea what the restrictions will be.”

Marcus and her counterparts across the University said they do know that every department will be expected to come up with 5 percent cuts in both personnel and non-personnel costs. But implementing these across-the-board cuts in every individual unit is not so simple; the amount each unit has to cut depends on a web of restricted endowments, unspent reserves, redistributed endowment funds, general spending and staffing structures that vary with each department.

Parsing those variations could make the difference between cutting down on photocopies or, at the other extreme, laying off employees. The reality will likely fall somewhere in between.

Hammering out those details has had the Provost’s Office, the Office of Budget & Planning and the Business Operations division spinning for months. Meanwhile, managers have been waiting to learn, in more concrete terms, their department’s fate. The tension underscores just how different the current budget process is from recent years and, in a larger sense, just how extraordinary these economic times are.

“I don’t really know at all what the upshot’s going to be,” Yale College Writing Center Director Alfred Guy said about how the cuts could affect the center’s services. “I absolutely don’t know what the specific effects are going to be.”

Associate University Librarian Danuta Nitecki said she could not comment on how next year’s budget will affect her spending plans without having any knowledge of the guidance. Director of Business Operations for Yale College Jane Lee, who oversees financial management, internal control and human resources for the college, said she is also waiting on the budget letter, adding that she is committed to making whatever cuts are requested.

Deputy University Secretary Martha Highsmith said she was not sure how or if Yale Security’s budget would be cut. But in case it is, she said the department could save money by delaying the replacement of police cars and other equipment, hopefully without having to cut staff.

“We understand that it’s a stressful time for budget managers,” Salovey said. “They’re having to make decisions that are unusual, that is, making cuts.”

Salovey said department heads are generally responding to the anticipated budget cuts in three ways. Some have begun looking for places to cut costs. Others are holding out to see what the budget memo will bring. Others still are hoping that the University will grow its way out of the budget deficit, which is what happened in 2005, the last time personnel and other costs were cut 5 percent.

But, Salovey said, that is almost certainly not going to be the case this time.

Another senior University administrator, who spoke on the condition of anonymity to avoid embarrassing colleagues, said the full impact of the cuts had not dawned on many managers, who act as if other departments will have to make sacrifices but not their own.

That issue is especially pronounced in small departments, where managers are wondering how they can reduce personnel costs by 5 percent when they already have such small staffs. Salovey said those departments may be incorporated into larger units for the purposes of this belt-tightening.

Traditionally, the planning memo signals the start of the budget season. That signal has not yet come, but Salovey said the budgeting process has started, even though departments still need to know their “bottom line.”

Salovey said departments should still have plenty of time to plan for the budget which takes effect in July. More importantly, the administration is waiting before sending the budget letter this year in order to benefit from the discussion of the Corporation, many of whose members are business and management experts.

The ultimate decision about how budget planning will unfold rests with the Corporation, Salovey said, which may modify the administration’s current plan to introduce reductions gradually rather than trying to recapture right away all of the lost revenue from the endowment’s 25 percent drop.

After the budget memo comes out next week, department heads will begin meeting with their deputy provosts to work out the details of their budget proposals.

Budget proposals from past years have been presented to the Corporation in April and approved in June. But because the challenges of this year’s budget have delayed the process, the Corporation will both consider this year’s proposal and make its final approval in June, Vice President for Finance and Business Operations Shauna King said last month.

Harrison Korn, Divya Subrahmanyam and Vivian Yee contributed reporting.