[3][4] He graduated from Dickinson College where he became a member of the Sigma Chi fraternity and the Raven's Claw Honorary Society, with a B.A.

In 1985, Gerlach moved back to Ellwood City and worked at the Butler law firm Lindsey & Lutz.

On March 6, 2020, the board of directors from the Greater Reading Chamber Alliance announced that Gerlach had been named president and CEO of the organization.

[6] In preparation for the 1990 election against long time Democratic State Rep. Sam Morris, Gerlach visited 10,000 homes in the 155th District of the Pennsylvania House of Representatives, building his campaign around what he saw as the incumbent's inattentiveness to suburban sprawl.

[7] During the election, Gerlach's Democratic opponents accused the Western Pennsylvania native of moving to Chester County for the sole purpose of running against Morris.

Gerlach denied that accusation and said he moved to Chester County because he and his wife saw it as "a great place to work and raise our kids."

[8] He defeated Democrat Barry Robertson (whose campaign was heavily funded by Sam Morris, Gerlach's opponent four years earlier)[9] in that election, and was re-elected in 1998 without opposition.

In 2009, Gerlach opposed HR 2454, which was designed to amend several laws related to energy and the environment, and included a "cap-and-trade" program to limit greenhouse gas emissions.

[20][21] He was one of four Pennsylvania Republicans (the others were Todd Platts, Charlie Dent, and Phil English) to vote to add sexual orientation and gender identity to the federal hate crimes bill.

[15] Gerlach defended this vote, saying, "Voting on this issue six months before Defense Secretary Robert Gates is scheduled to issue a thorough review of the policy and how best to implement any changes does nothing to improve the security of our country or the morale of the brave men and women serving in our military.

"[16] In 2007-2008, Gerlach received a 64 percent support rating from the Family Research Council,[18] an interest group whose mission statement commits it to being an organization that "shapes public debate and formulates public policy that values human life and upholds the institutions of marriage and the family.

"[15] In a statement on the Health Care vote, Gerlach stated that the bill was "written behind closed doors," and that it "ushers in a new era of big government.

"[16] Gerlach also expressed concerns about the bill's impact on his constituents, saying "In my district, innovation, investment and jobs in the life sciences and biotechnology sector will be at risk because of a new $2 billion per year tax on items used for cancer screening, knee and hip replacement surgery and other life-saving procedures.

[24] In 2015, Gerlach was announced as the new president and chief executive officer of BIPAC, the Business-Industry Political Action Committee.

Gerlach was the only member of the "Philly Trio" of vulnerable Republican Congressmen (the others being Curt Weldon and Mike Fitzpatrick) to survive the 2006 election.

He overcame a negative political climate that included the then-unpopular war in Iraq, an unpopular president and a well-liked Democratic governor.

[37] He faced the Democratic nominee Manan Trivedi, an Iraq war veteran and physician, but won re-election with 57% of the vote.