Which modifier should be used when an employer's workers' compensation payer requires bloodwork for a work-related injury?

The correct choice for indicating that bloodwork is required for a work-related injury, particularly in the context of workers' compensation, is the modifier that signifies a service that is mandated by a third party. In this case, the -32 modifier is the appropriate choice because it indicates that a service or procedure is mandated by a governmental or third-party payer. This reflects the concept that the bloodwork is necessary for the treatment or evaluation of an injury that is being covered under the employer's workers' compensation insurance.

The other modifiers do not align with this situation. The -47 modifier is used to indicate that a procedure was performed with anesthesia, which does not pertain to the requirement for bloodwork. The -50 modifier denotes bilateral procedures, affecting both sides of the body, but does not apply to the context of mandated testing. The -99 modifier is a general modifier for multiple modifiers, but it does not serve the specific purpose of indicating a mandated service by a payer. Thus, the use of the -32 modifier clearly communicates the requirement placed on the provider by the workers' compensation payer.