But if the Yankees catcher has his way, Craniosynostis will not be hard to cure in the not-too-distant future.
"I really want to give back and didn't know how to give it," Posada said of his first impulse.
Jorge Posada, Jr., now 7, was born with Craniosynostis.
"It affects the bones in the skull," the elder Posada said. "They fuse together before the brain grows. You need space so the brain can grow normally.
"In my son's case, it was closed on the left side, so his brain was growing abnormally. Sometimes it's genetic, sometimes it's not. In our case, it wasn't genetic."
Posada formed his own foundation in the fall of 2000 to direct fund-raising proceeds to families who suffer from Craniosynostis, and to provide athletic programs for children in New York and his native Puerto Rico.
His early efforts earned Posada the 2001 Thurman Munson Award for both philanthropic work and baseball accomplishments. More recently, he received the Bart Giamatti Award at the 2007 Baseball Assistance Team (BAT) dinner, recognizing the individual associated with the baseball community who best exemplifies the compassion demonstrated by the late commissioner.
While Posada has been building his fund-raising programs, Jorge Jr. has undergone eight operations.
"He's doing great," Posada said. "He should be all right. I think this will be his last operation. Sometimes it takes seven, eight operations, sometimes only one.
"I met a guy in a Starbucks whose son was having an operation today. It's a tough condition, but it's correctable when it's not genetic."
More than just raising money, Posada wants to educate the public about Craniosynostis.
"People in New York know I'd like to spread the word out a little more," he said. "I would like to raise a little bit more awareness, people knowing I'm helping kids with this condition."
The Yankees' YES cable network has helped Posada. The next step is national baseball-carrying networks like Fox and ESPN.
"It takes a little more time when it comes to big networks," he said.
The Posada Foundation conducts annual galas in New York and Puerto Rico. The first Family Day in January 2006 in Puerto Rico featured games, rides, food and live entertainment.
Any support from the public is "really appreciated" by Posada.
"It's not about numbers anymore," he said. "It's what people send in through letters and money to the foundation."
Posada has had one very high-profile donor - his own boss.
"Mr. (George) Steinbrenner has been the one consistent donor each year," he said. "Every year it (donation amount) changes. Dollar amounts are not important. I've been really blessed he's been a part of this."
The blessing Posada has enjoyed more is the improving condition of Jorge Jr., who is starting to play baseball himself with no restrictions. He and wife Laura also have a daughter, Paulina, 4.
This longtime Yankee appreciates his four World Series rings. But in the end, the health of a child means a lot more.