It's usually the lawyer who starts bringing in business that thinks about leaving their law firm. But now we're in a time when leaving may not be so voluntary.
I learn about lawyers leaving law firms in two ways - I'm told by the lawyer, or I read about it in the paper. A quick blurb on page 3 of the business section is always preferable to a front page story, which usually means there's a lawsuit.
Florida, where I practice, has a specific rule. It's long, detailed, and basically says this:
 Clients have the right to counsel of their choice, regardless of what lawyers and law firms say.
 Absent a specific agreement otherwise, a lawyer who is leaving a law firm shall not unilaterally contact those clients of the law firm for purposes of notifying them about the anticipated departure or to solicit representation of the clients unless the lawyer has approached an authorized representative of the law firm and attempted to negotiate a joint communication to the clients concerning the lawyer leaving the law firm and bona fide negotiations have been unsuccessful.
 Dissolution of Law Firm. Absent a specific agreement otherwise, a lawyer involved in the dissolution of a law firm shall not unilaterally contact clients of the law firm unless, after bona fide negotiations, authorized members of the law firm have been unable to agree on a method to provide notice to clients.
 When a joint response has not been successfully negotiated, unilateral contact by individual members or the law firm shall give notice to clients that the lawyer is leaving the law firm and provide options to the clients to choose to remain a client of the law firm, to choose representation by the departing lawyer, or to choose representation by other lawyers or law firms.
 When a law firm is being dissolved and no procedure for contacting clients has been agreed upon, unilateral contact by members of the law firm shall give notice to clients that the firm is being dissolved and provide options to the clients to choose representation by any member of the dissolving law firm, or representation by other lawyers or law firms.
 Notice to the client required under this rule shall provide information concerning potential liability for fees for legal services previously rendered, costs expended, and how any deposits for fees or costs will be handled. In addition, if appropriate, notice shall be given that reasonable charges may be imposed to provide.
There's nothing worse than leaving a law firm because the "big fee" came in, and then having to spend that big fee on lawyers.
Before you jump ship, know whether your jurisdiction has a specific rule, and follow it. If agreements can't be reached, legal action may be unavoidable, but I can guarantee you a long term of worthless litigation if you take no action to try and resolve your departure amicably.
Located in Miami, Florida, Brian Tannebaum practices Bar Admission and Discipline and Criminal Defense. He is the author of I Got A Bar Complaint.