CPT 10140 refers to the surgical incision and drainage of a hematoma, seroma, or other localized fluid collection within the skin or subcutaneous tissues. This procedure is a fundamental surgical intervention used to manage accumulations of blood (hematoma), serous fluid (seroma), or other non-purulent fluids that occur as a result of trauma, surgery, or inflammatory processes. A hematoma is a localized collection of blood outside the vascular system, which can become painful, cause tissue tension, or provide a medium for bacterial growth. A seroma is a collection of sterile fluid, often occurring in the dead space created during surgical dissections, such as after a mastectomy, hernia repair, or abdominoplasty. The procedure for 10140 involves several distinct clinical steps. After identifying the fluid collection through palpation or ultrasound and obtaining informed consent, the clinician cleanses the site with an antiseptic agent and administers local anesthesia. A scalpel is then used to make a deliberate incision through the epidermis and dermis, extending into the fluid-filled cavity. This is distinguished from simple aspiration (10160) because the incision allows for the evacuation of clotted blood, fibrin, or viscous fluid that cannot be easily withdrawn through a needle. The clinician may use blunt dissection or a hemostat to break up internal loculations. Following evacuation, the cavity is often irrigated with sterile saline. Depending on the volume of the collection and the risk of re-accumulation, a drain may be placed or the wound may be packed with gauze. The physician's documentation must specify the anatomical location, the characteristics of the fluid, and the method of drainage to support the use of this code.