Phototherapy is a cost-effective treatment for many dermatoses, yet the emergence of alternative therapies such as biologics led many to think that phototherapy utilization was declining.

To characterize national, historical phototherapy utilization and costs among Medicare beneficiaries.

Longitudinal analysis of the Medicare Part B National Summary Data File from 2000 to 2015 for phototherapy billing codes. Geographic distribution of clinics and provider type obtained from the Medicare Provider Utilization and Payment Data for 2012 to 2015.

The overall volume of phototherapy services billed to Medicare from 2000 to 2015 increased by 5% annually, from 334,670 to 692,093. Ultraviolet B therapy comprised 77% of phototherapy volume, utilization of psoralen plus ultraviolet A therapy declined by 9% annually, and excimer laser services grew by 29% annually. The number of phototherapy clinics is increasing but remains concentrated in only 11% of US counties. Between 2012 and 2015, dermatologists accounted for 92% of phototherapy volume.

Commercial payers and institutional claims (hospital-based physicians) are excluded. Clinical indications for phototherapy use are not reported in this database.

Phototherapy utilization has grown, though the service mix has shifted toward ultraviolet B and laser excimer therapy and away from psoralen plus ultraviolet A therapy. Dermatologists manage most phototherapy. Uneven geographic distribution of phototherapy clinics limits access in nonurban areas, and further evaluation is needed to determine its impact on rural communities.