Background: Mixed results exist regarding the benefit of orthobiologic injections. The purpose of this study was to assess the variability in costs for platelet-rich plasma (PRP) and stem cell (SC) injections and evaluate for variables that influence pricing. Hypothesis: There will be significant variability in the cost of PRP and SC injections throughout the United States. Study Design: Descriptive epidemiology study. Level of Evidence: Level 3. Methods: Calls were made to 1345 orthopaedic sports medicine practices across the United States inquiring into the availability of PRP or SC knee injections and associated costs. In addition to pricing, the practice type, number of providers, and population and income demographics were recorded. Univariate statistical analyses were used to identify differences in availability and cost between variables. Results: Of the contacted offices that provided information on both PRP and SC availability (n = 1325), 268 (20.2%) offered both treatments, 550 (41.5%) offered only PRP injections, 20 (1.5%) offered only SC injections, and 487 (36.8%) did not offer either treatment. The mean ± SD cost of a PRP injection was $707 ± $388 (range, $175-$4973), and the mean cost of an SC injection was $2728 ± $1584 (range, $300-$12,000). Practices offering PRP and SC injections tended to be larger (PRP, 12.0 physicians per practice vs. 8.1 [P < 0.001]; SC, 13.6 vs 9.7 [P < 0.001]). Practices that offered PRP injections were located in areas with higher median household income (P = 0.047). Variables associated with higher cost of PRP injections included city population (P < 0.001) and median income of residents (P < 0.001). Conclusion: While the majority of sports medicine practices across the United States offer some type of orthobiologic injection, there exists significant variability in the cost of these injections. Clinical Relevance: This study demonstrates the significant variability in costs of orthobiologic injections throughout the country, which will allow sports medicine physicians to appreciate the value of these injections when counseling patients on available treatment options.