Background: Although American Society for Radiation Oncology (ASTRO) guidelines support single fraction radiation treatment for uncomplicated bone metastases, it is rarely used. Methods: We used modified RAND/UCLA appropriateness methodology to understand how radiation oncologists make decisions about single fraction treatment to inform quality improvement. We focused on uncomplicated bone metastases (defined by relevant RCT exclusion criteria) without prior irradiation, pathologic fracture, or spinal cord compression. Eight radiation oncologists with varying sub-specialties were provided ASTRO guidelines, a summary table of RCT’s and recent research on current practices. They rated the appropriateness of 8Gy Single Fraction treatment and 4 alternative regimens for clinical cases before and after a panel discussion that also included three palliative care physicians. Clinical cases varied by location of metastases (spine, humeral head, femur, rib), size of metastases, patient prognosis, travel distance to treatment site, and patient age. We report findings based on final median appropriateness ratings and qualitative evaluation of discussion. Results: Single fraction treatment (8Gy) was rated as the most appropriate treatment, regardless of other factors if prognosis was 6 months or less. However, participants noted that prognostic information is often not available at the point of care. Use of greater than 10 fractions was rated as inappropriate regardless of other factors. Older age and travel distance were factors that lead to favoring 8Gy single fraction treatment. There was less consensus concerning single fraction treatment and favoring of other treatment approaches for lesions located on the spine, especially large lesions, and for patients with oligometastases and a longer prognosis where goals may include local tumor control in addition to palliation. Conclusions: Improving specification and communication of prognostic information is an important quality improvement target to enhance the patient-centered nature of care for patients with painful bone metastases.