Rule 5.4 Professional Independence Of A Lawyer
(a) A lawyer or law firm shall not share legal fees with a nonlawyer, except that:
- an agreement by a lawyer with the lawyer's firm, partner, or associate may provide for the payment of money, over a reasonable period of time after the lawyer's death, to the lawyer's estate or to one or more specified persons;
- a lawyer who purchases the practice of a deceased, disabled, or disappeared lawyer may, pursuant to the provisions of Rule 1.17, pay to the estate or other representative of that lawyer the agreed-upon purchase price;
- a lawyer or law firm may include nonlawyer employees in a compensation or retirement plan, even though the plan is based in whole or in part on a profit-sharing arrangement; and
- a lawyer may share court-awarded legal fees with a nonprofit organization that employed, retained or recommended employment of the lawyer in the matter.
(b) A lawyer shall not form a partnership with a nonlawyer if any of the activities of the partnership consist of the practice of law.
If you're really interested read an ABA formal opinion related to fee divisions here.