Born Chastity, the son of '60s pop icons Sonny and Cher, Bono says he knew from an early age that he was born in the wrong body. Since going public in 2009, he has injected himself with testosterone, grown body hair and surgically removed his breasts.
Now, the "Dancing With the Stars" contestant has told Rolling Stone magazine that "within a short while he will finally be able to afford to get himself a penis."
Bono said that he has looked into either the simplest procedure that uses clitoral tissue to build a micro-penis or a full phalloplasty, where surgeons take skin from another part of the body and roll it to create a phallus that is attached to the groin.
"It's true, it's something he will consider at the appropriate time," Bono's publicist Howard Bragman told ABCNews.com. "But it's not something that is imminent and not something he believes will make him a man. He feels comfortable with his own masculinity."
"Gender is between your ears and not between your legs," said Bragman. "And he knows it's an imperfect surgery and that he will either get something small with some feeling or something normal that doesn't have any feeling."
Medical experts say that less than half of all who are transgender will ever go on to have genital surgery. And those who transition from female to male are even less likely to take that step because it is complicated, expensive and not always successful.
About one-quarter to 1 percent of the population is born transgender, according to the National Center for Transgender Equality.
Medical experts say that many know by the age of 6 that their physical gender does not match their identity.
"Most people describe rejecting those feelings and they can get depressed with the sense that they are living a lie," said Dr. Jeffrey Spiegel, chief of facial plastic surgery at Boston University School of Medicine. "But with therapy and information, they come to see that it is a disorder."
"For many people, the goal is to transition in a way that they disappear from special scrutiny," he said. "The goal is to blend in."
Bono said that as girl he loved to box and his hero was Sylvester Stallone. Though his father never lived to know that he was transgender -- Sonny Bono was killed in a ski accident in 1998 -- his glamorous mother had a difficult time accepting her masculine daughter.
"As far back as I can remember, my mother always seemed to want me to act more like a girl," Bono wrote in his book, "Transition: The Story of How I Became a Man."
At first, in the 1990s, Chastity came out as a lesbian, but in 2009 she announced her transition to a man.
Bono has said that he has never been happier. He stopped smoking and other vices, including abusing alcohol and painkillers. When a transgender friend told him the male nipples Bono had surgically recrafted and reattached would fall if he continued to smoke, he gave up the habit.
"It's a graft and grafts don't always heal," he told Rolling Stone.
Today many children who are born transgender begin hormone blockers in early puberty before sex characteristics have developed.
But Bono, now 42, began his transition much later and had already developed breasts.
Guidelines for standards of care are set by the World Professional Association for Transgender Health as those who are transgender explore and transition from one gender to another.
They may include counseling, a "real life" experience living in the target gender for a trial period and learning about the available options and effects of medical treatments.
Some seek facial changes -- a wider jaw for a man. Shaping the skull and eye sockets, reshaping the chin and other surgical procedures can help a person look more like the target gender.
Hormone treatments, like the ones Bono takes, are highly effective in women transitioning to men, according to plastic surgeon Spiegel.
"Trans men like Chaz are relatively lucky compared to trans women," he said. "Almost any woman with androgenizing hormones would easily pass as a man."
Transgender Female-to-Males Transition Easier
Genital surgery is "less significant" to most transgender people if hormones effectively change their appearance and "they are happy with the way they look," said Spiegel.
When female-to-male patients do opt for surgery, like Bono, doctors start with the nerve-rich clitoris to begin build a penis -- and to preserve some sexual sensation.
"The male and female genital structure is basically homologous," said Dr. Loren Schechter, head of plastic surgery at Chicago Medical School at Rosalind Franklin University of Medicine and Science and the Chicago Gender Center.
He does scores of what he calls "gender confirmation" surgeries annually.
Male-to-female surgery is five times more common than the surgery that Bono says he would like to have.
"The reason is cost and a major factor is the risk of complications," said Schechter. "It's not ideal, and it's a difficult operation."
Phalloplasty can run as high as $50,000 to $75,000, while vagina reconstruction costs about $21,500. Only about a fifth of all patients have insurance plans that cover these procedures, he said.
Hormone treatments with testosterone make the clitoris grow, sometimes to an inch or two, so surgeons can simply lengthen it in metoidioplasty -- the least invasive procedure.
They release the restraining ligaments that hold the clitoris next to the public bone and give the patient enough of a penis to urinate while standing, but not to have intercourse.
"When doing gender confirmation surgery, people know who they are and the goal is to make the body congruous with the mind," said Schechter
Sexual performance is not always of concern. "Most want to just pass as a member of the opposite sex and not be hassled when they walk into a male bathroom," he said.
In addition to lengthening the clitoris, doctors can create a urinary tube through the micro-phallus by using portions of the labia and minor or the vagina.
The third and riskiest option involves "flaps" or transferring tissue from a distant part of the body such as the forearm or the back or thigh and inserting a penile prosthesis.
"The goal is to truly reconstruct a penis," he said.
Bono has said he has been in contact with a doctor from Belgrade in Serbia. There, according to Schechter, Dr. Rados Djinovic is an expert in reconstructive surgery.
"Europe has some outstanding surgeons," said Schechter, who has worked with Djinovic.
He said that his medical colleagues had coincidentally talked about Chaz Bono's decision in the operating room this week.
"It's all about education, and from a physical standpoint, helping people who need help," he said. "There shouldn't be a stigma associated with it ... This condition has been known throughout time and history and different cultures."
"We are trying to make people feel comfortable in their own body," said Schechter. "Not everyone wants it or is a candidate for it, but there's an entire spectrum of options open to them."