11 U.S.C. § 331 — Interim compensation

A trustee, an examiner, the debtor's attorney, or a professional person employed under section 327 or 1103 may apply to the court for compensation for services already rendered, or reimbursement for expenses already incurred, as provided under section 330. They cannot apply more than once every 120 days after the order for relief in the case, unless the court permits more frequent applications. After notice and a hearing, the court may allow and disburse compensation or reimbursement to that applicant. This lets these participants get paid along the way, instead of waiting until the whole case is finished, while the actual standard for what counts as reasonable compensation is set out in section 330.