Montgomery County Chief Administrative Officer Timothy Firestine (Courtesy of Timothy Firestine)

Montgomery County, facing an estimated $179 million budget shortfall, has frozen most hiring and purchasing for the remainder of fiscal year 2015, officials said Wednesday.

Chief Administrative Officer Timothy Firestine has also directed county departments to prepare their proposed budgets for fiscal 2016 — which begins July 1 — assuming a 3 percent spending cut.

The belt-tightening, outlined by Firestine on Monday in a series of memos to department directors, is a response to lower-than-projected tax revenue, the result of a state economy still in a sluggish recovery from the recession.

“I fully appreciate the challenges these controls will present,” Firestine wrote. “However, these measures are necessary at this time because of the very difficult constraints we are facing as we prepare the FY16 operating budget.”

The county’s move mirrors similar spending restrictions announced last week by Montgomery County public schools.

While the county’s freeze reflects concern about its financial outlook, it stops short of more stringent steps taken in years past. To deal with significant budget deficits during the depth of the financial downturn, the county imposed midyear savings plans that required departments to cut operating budgets by millions of dollars.

The freeze disclosed by Firestine is also loaded with exemptions. The moratorium on hiring does not include 14 job groups, including police, firefighters, correctional officers, bus drivers and crossing guards.

Purchasing related to the county’s capital improvements program and certain contracts are also exempt.