Background: Although timeliness of care was one of the aims of quality improvement in the Institute of Medicine’s 2001 “Crossing the Quality Chasm” report, a significant proportion of patients with cancer still experience delays in diagnosis and treatment. For example, in a study of 3,831 older adults diagnosed with myeloma in the United States, the median time between the first myeloma-related symptom and diagnosis was 99 days (Friese CR, Leukemia & Lymphoma 2009). Such delays are associated with substantial anxiety, poor patient-reported outcomes, and increased cost. Methods: A novel adult cancer diagnostic service (CDS) was established by the Dana-Farber/Brigham and Women’s Cancer Center in October 2017. The clinic is embedded in the Department of Medicine at the Brigham and Women’s Hospital, with the aim of expediting the cancer diagnostic work-up and treatment for clinically complex patients with symptoms concerning for cancer, but for whom the next diagnostic steps are unclear. This clinic is comprised of an internist, a physician assistant, and a practice assistant. The clinic staff conduct a weekly phone conference with a multidisciplinary team—including a solid tumor oncologist, a hematologic oncologist, and a radiologist—to discuss the work-up for each patient. For every patient evaluated who receives a cancer diagnosis, we measure the diagnostic interval (days from CDS referral to diagnosis date). We define diagnosis date as the date the pathologic report is signed. We also measure the interval between CDS referral and first oncology appointment. Results: From the inception of the CDS to October 1, 2018, 221 patients were seen in the clinic and 91 (41.2%) were diagnosed with cancer. The top 3 cancer diagnoses were lymphoma (31%), gastrointestinal cancers (20%), and lung cancer (19%; Figure 1). The median number of days from CDS referral to diagnosis was 14 days (interquartile range [IQR], 10, 21; Table 1). Finally, the median time between referral to CDS and first oncology appointment was 20 days (IQR, 14, 27). Conclusion: This novel cancer diagnostic service substantially shorted the diagnostic trajectory (∼2 weeks) compared to existing literature with median diagnostic intervals often lasting more than 3 months (Friese CR, Leukemia & Lymphoma 2009). Our findings suggest that a cancer diagnostic care model, grounded in internal medicine, with engagement of oncologists and radiologists, has significant potential to improve delays in cancer diagnostic care.