We characterized patients initiating abaloparatide (ABL), teriparatide (TPTD), or denosumab (DMAB) in a real-world clinical setting from a large medical and pharmacy claims database. Differences were noted in sex, age, pathologic fractures, comorbidity index, and prior bisphosphonate use for patients initiating ABL and TPTD compared with those receiving DMAB. Introduction To characterize patients initiating abaloparatide (ABL), teriparatide (TPTD), or denosumab (DMAB) treatment in a real-world clinical setting. Methods Patients aged ≥ 18 years initiating ABL, TPTD, or DMAB between May 1, 2017, and September 24, 2018 (without receiving the same drug in the previous 12 months), were identified using the OM1 Data Cloud, which contains medical and pharmacy claims from approximately 200 million US patients. The index date was the date of initial prescription or dispensing for ABL, TPTD, or DMAB during the study period. Results During the study period, 2666 patients initiated ABL, 9210 TPTD, and 116,718 DMAB. Mean age (standard deviation) was 69.2 (10.6) years for the ABL cohort, 68.6 (11.3) for TPTD, and 72.1 (10.2) for DMAB (P < 0.001; ABL vs DMAB). Proportionally more patients initiating ABL were female (95.2% ABL, 86.9% TPTD, and 91.3% DMAB, P < 0.001 ABL vs TPTD or DMAB). Nearly twice as many patients initiating ABL (19.1%) and TPTD (18.8%) had a previous pathologic/fragility fracture vs DMAB (9.6%; P < 0.001 ABL vs DMAB). Fewer patients initiating ABL (36.3%) or TPTD (39.7%) had Charlson comorbidity index of ≥ 2 vs DMAB (48.4%; P < 0.001 ABL vs DMAB). Before initiating ABL, TPTD, or DMAB, 44.3%, 33.8%, and 33.9% of patients had prior osteoporosis treatment, respectively. Bisphosphonate use was more common before initiating ABL (19.2%) or TPTD (19.6%), than before initiating DMAB (16.6%; P < 0.001 ABL vs DMAB). Conclusions Patients initiating ABL and TPTD differed in sex, age, pathologic fractures, comorbidity index, and prior bisphosphonate use compared with those initiating DMAB.