So you didn’t have a bar mitzvah at 13. Not to fear. Like high-top sneakers, they aren’t just for teenagers anymore.

Conservative synagogues began offering adult b’nai mitzvah in the early 1970s to men and women, and today the Reform movement is embracing the practice with gusto, with the numbers to prove it.

Typically adults who have b’nai mitzvah either grew up Orthodox, didn’t want one at the time or became Jews by choice as adults. For these reasons, the majority of adults who have b’nai mitzvah are women in their 40s or beyond, followed by men in their 30s or older.

Rabbis at local Reform and Conservative (the Orthodox movement doesn’t offer programs) congregations say that the bulk of their b’nai mitzvah students are doing something they couldn’t do as teenagers, either because of gender restrictions, teenage alienation from Judaism or having grown up in a country where Jewish practices were unfamiliar or lost.

What does it take to get to the bimah as an adult, especially a busy adult who might have a job, or children or both? A typical adult b’nai mitzvah program requires two years of study, including basic Hebrew, Torah and Haftarah as well as other material designed to nurture a longer-term, spiritual connection to Judaism. Some programs are only a year long, but they are geared toward students who know more Hebrew.

But more important than Hebrew or knowledge of Torah, rabbis and educators say, is dedication to the process. Adults also have some pluses — life experience to draw from and a desire to succeed that has nothing to do with parental nudging. “An adult has a much more mature understanding of what they are committing to [and] a much deeper ability to analyze and integrate concepts into their lives,” said Rabbi Nat Ezray of Temple Beth Jacob in Redwood City.

If you’re thinking about becoming an adult b’nai mitzvah, here’s what you can expect at these Bay Area synagogues.

Congregation Beth El

Five years ago when the adult education committee asked Cantor Brian Reich of Congregation Beth El to bolster their program, Reich came up with the idea of an adult b’nai mitzvah program.

Apparently it was the right idea at the right time. In its first year, the yearlong program at the Berkeley Reform synagogue “maxed out” at 18 students. Since then, the program has had enough students to run at least three different class sections per cycle.

Even if students only know Hebrew letters, they can still take his course and be successful, Reich said. “They’re not going to feel left behind,” he said, adding that although students have varying levels of knowledge, they are willing to help each other.

Reich employs several experiential components and exercises to help students integrate the material into their lives, including writing down why they want to become b’nai mitzvah and exchange responses with other students.

Congregation Shir Hadash

Shir Hadash, a Reform congregation in Los Gatos, has a well-established program that was created for maximum flexibility for those with time constraints. In the past few years, the number of participants has ranged from seven to 22.

Rabbi Melanie Aron, who is in charge of the program, finds that weekly classes allow members to support each other.

The goal of the program, offered every other year, is to make sure all participants get equal attention. Those with basic or minimal Hebrew skills can join a year earlier to study Hebrew skills, while and those with more advanced Hebrew-reading skills can “walk right into the class,” she said.

“When people don’t know the prayers, they don’t feel comfortable in the synagogue,” Aron said. “They feel like outsiders. People who do this program become really comfortable in the synagogue. It’s a whole different relationship they have to their Jewish identity.”

Congregation Sherith Israel

Sherith Israel, a Reform San Francisco congregation, has a program that cantor Rita Glassman feels passionate about.

The 10-year-old program has an average of six to 10 participants per cycle who participate in 14 months of study and preparation. Everyone, including those with beginner Hebrew skills, is highly encouraged to take the course. In addition, those do not want a public ceremony can take the classes but opt out of the ceremony.

Glassman brings her own flavor to the course by using a wide range of contemporary material and media to teach the students more about Judaism, including videos on the Holocaust, recordings of world music and recipes.

Currently eight students are enrolled, and all are expected to become bar or bat mitzvahed by 2008. Of the eight, all were born Jewish and have deeply personal reasons for being there. “What they all have in common is a deep yearning to understand better their Jewish heritage, the language of prayer and Torah, and to connect more consciously to Judaism and the Jewish world,” Glassman said.

Temple Beth Jacob

Temple Beth Jacob has one of the longest-running programs in the Bay Area. The Conservative shul officiated its first set of b’nai mitzvahs in 1963 for 18 grown men, said Rabbi Nat Ezray.

In recent years, Ezray has divided the program from one large group (usually 13) into several small groups, holding a series of small ceremonies over several weeks.

Ezray said many of the students had a bar or bat mitzvah in the past, but enter the program because they want to “rededicate themselves to their Judaism.”

The program is designed so that family members and participants can bond, Ezray said. To achieve this, Ezray gives each student a wealth of reading material based on his “individual insights.” He also requests that, at the ceremony, family members present the student with a book that reflects his or her interests and commitment to study. He also records audio of each class session, and students frequently call in to get a copy of what they missed.

For those unable to do the b’nai mitzvah within the classroom setting, Ezray conducts individual ceremonies. “We really want to give people the skills to stay involved and active after the program,” he said.

Temple Beth Torah

During the last two-year cycle at Temple Beth Torah in Fremont, three women had bat mitzvahs. Andrea Fleekop, director of education, said most of the adults in their program either grew up Orthodox or in a world where b’nai mitzvahs weren’t done.

“These women therefore want to be part of the community and participate in a rite of passage,” she said. The weekly classes enable adults to have “conversations about spirituality and different aspects of Judaism” that they otherwise might not have been able to have.