More than 188,000 children are enrolled in the program, but the number has dropped by 7,700 over the last several years, according to the Insurance Department.
The agency blames a lack of advertising for the decline.
Advocates for children said they were thrilled that the program had been preserved and would reach more children, who will be able to get health care faster.
"In my entire career, I can't think of a single initiative with as much bipartisan support as CHIP," said Joan Benso, executive director of Pennsylvania Partnerships for Children. "I'm glad the governor committed more outreach funds and eliminated the waiting period, which was a weak part of the policy."
The waiting period applied to higher-income recipients who pay a portion of CHIP care, not lower-income families that qualify for free CHIP.
The period was instituted during Ed Rendell's administration to discourage parents from dropping private insurance and switching to the plan, but Benso said there was no evidence that anyone tried to do so.
Rep. Ed Nielson (D., Phila.), a cosponsor of the bill, said providing basic preventive care will help keep children out of costly emergency rooms.
During fiscal 2010-11, Pennsylvania hospitals provided almost $1 billion in uncompensated care, a 46 percent increase from five years earlier.
"The bill that was signed into law today is a simple solution to a complex problem," Nielson said. "There is still plenty of work to do, but I am encouraged by this solid start."
Sen. Vincent Hughes (D., Phila.) said the CHIP extension would be moot - and millions of dollars saved - if Pennsylvania complied with the Affordable Care Act's Medicaid expansion provision and allowed low-income children to be shifted to Medicaid.
The Corbett administration is seeking a waiver from the Department of Health and Human Services to keep the state's children on CHIP.
Corbett spokeswoman Christine Cronkwright said, "It's a necessity to keep the program going regardless of what eligibility looks like following discussions with HHS."