"I'm running to replace (Republican Gov.) Tom Corbett. That's what this race is about," the fifth-term congresswoman said in a telephone interview.
Schwartz, 64, who has said for weeks that she intended to run, filed papers Monday with the Pennsylvania State Department to set up a state fundraising committee.
She also transferred $3.1 million into the new committee, nearly all of it from her congressional campaign committee and the remainder from a state legislative campaign committee, campaign spokeswoman Reesa Kossoff said.
Schwartz served in the state Senate for 14 years before being elected to Congress. She faces a potentially crowded field in a gubernatorial primary that's more than a year away.
Other declared candidates include Tom Wolf, a York County businessman and former state revenue secretary who has pledged to sink at least $10 million of his own money into the primary campaign, and state government veteran John Hanger of Dauphin County.
Several others are still considering entering the race, including state Treasurer Rob McCord and former U.S. Senate nominee Joe Sestak.
Schwartz is an advocate of abortion rights and gun control but has a more moderate record on other issues. For example, a bill she sponsored in her first term to provide tax credits to businesses that hire unemployed veterans was passed and signed into law.
She vowed that her Pennsylvania political campaign would not interfere with her duties in Washington.
"I'm blessed with great energy and focus," she said.