In the US you don't need to graduate from a bartending school in order to become a bartender. In certain states you are required to attend an Alcohol Server Training program which teaches alcohol safety, preventing underage drinking, drunk driving, etc... Most establishments do not require that you attend an actual bartending school.
The general consensus among most bartenders today is that attending a school isn't necessary. As we've discussed throughout the site, most bartenders work their way up from either a food server position, or by working as a barback. In fact the "job placement" help that most schools offer often ends up being temporary catering jobs. It's rare to go straight from a bartending school into a full time job at a nice bar.
Although many of them are fairly expensive, bartending schools can be helpful for people new to the industry. You'll learn how to free pour. You'll practice mixing drinks in the schools training bar. You'll learn oodles of drink recipes. You'll also have an experienced instructor on hand to answer the many questions you'll have.
Unfortunately the benefit you'll gain from adding the school to your resume is limited. When hiring new bartenders managers look for experience first. You may have performed admirably when pouring drinks in the safety of the training bar, but remembering seven drink orders on a hectic Saturday night when the music is blasting and the lights are low is a whole different matter. It takes time and experience to build your skills up to the point where you can work under these conditions.
The main reason to attend a bartending school is to gain confidence. Another good reason is to gain some insight into whether the job is a good fit for you. Bartending isn't for everyone and by attending a school you'll find out fast whether it's something that you wish to pursue. You'll also learn the tricks of the trade and hear stories from a knowledgeable instructor about what it's like to be in the industry.
If you're interested in attending a bartending program, we suggest checking out your local community colleges first. This is what I did years ago and found the class to be interesting and worthwhile. It was also significantly cheaper than attending one of the more popular, advertised bartending schools.
Whichever path you choose persistence is what really matters. It can take some time to land your first bartending gig. Don't give up! Bartending can be a rewarding and very enjoyable career!