The Advocacy Council regularly receives queries from members on how to correctly code specific scenarios. Recently we received a request for assistance from a practice regarding the difference between rush and cluster immunotherapy and coding for each.
- Rush immunotherapy for inhalants is usually performed over one to two days. Several dosing schedules are used. Generally, the immunotherapy injections are given every 30 minutes over several hours. If two or three vials are used, (e.g., molds in one, pollens in another) then two or three shots may be given at each 30-minute interval. The patient’s vital signs are monitored, and the patient is observed closely during the build-up. The provider should be present in the office. CPT 95180 for rapid desensitization can be used. 95180 is an hourly billing code (one hour = one unit). If the RUSH injections are given every 30 minutes, in a typical one-day RUSH you may give four shots (one out of each vial in a two-vial set) in one hour, 30 minutes apart: i.e., two at 8:30 am; two at 9:00 am, etc. If 24 shots were given over six hours, you can bill 95180 x six units (six hours).
- Cluster would be the same – usually only two hours for two to three days a week. One unit can be billed for each hour or more the patient is in the office for the shots and under direct observation. (Generally, one and a half to two hours)
- As in all procedures, clear and thorough documentation is very important.
- Some carriers (e.g., Humana) do not cover RUSH or cluster for inhalant immunotherapy. If uncertain, contact your carrier.
Venom immunotherapy often begins with three injections of very dilute antigen given each week for a number of weeks but is neither cluster or rapid desensitization. It is billed as one unit of the venom code, depending on the number of stinging insects plus 95117 (for the administration of two or more injections).
At times it is the diagnosis code that determines whether an insurance carrier will pay, so you should know which diagnosis codes a carrier accepts. A list of paired CPT/ICD-10 codes can be found on each carrier’s website.