Chronic migraine is a diagnosis that can be abstracted through the clinical history, although some providers may struggle in properly applying diagnostic criteria. We aimed to learn how well medicine trainees would be able to recognize the diagnostic criteria for chronic migraine and apply that medical knowledge to case vignettes illustrating different symptom interpretation strategies of the identical information. An electronic, anonymous and multiple-choice response questionairre assessing selected trainee characteristics, headache case vignettes, and chronic migraine diagnostic criteria was distributed to all regional medicine program directors and coordinators in Kentucky and surrounding states. Program directors and coordinators could then individually decide whether or not they would forward to their trainees. The primary outcome measure was the frequency of chronic migraine recognition as a function of history style (ie, lumping versus splitting). Secondary outcome measures included recognition of chronic migraine diagnosis as a function of program affiliation (academic versus community), training year, gender, and recognition of ICHD-3 beta chronic migraine diagnostic criteria. Nominal variables were described as counts and percentages, and compared using chi-square tests. Statistical tests were considered to be two-sided and P ≤ .05 was considered to be statistically significant. Statistical analyses were performed using the JMP 11.0.0 (SAS Institute Inc., Cary, NC, USA). Fifty-six medicine trainees completed the survey. Episodic migraine and chronic tension-type headache were correctly recognized by 85.7% and 96.4%, respectively. Chronic migraine was recognized by a greater proportion of trainees when the identical information was presented using a lumped versus split symptom interpretation strategy (24.1% vs 3.6%, chi-square = 6.5, df =1, P = .01). Accurate recognition of chronic migraine was more likely among trainees in community versus academic/university program (40% vs 14.7%, chi-square = 4.4, df = 1, P = .03) and among male versus female trainees (33.3% vs 9.5%, chi-square = 3.9, df = 1, P = .04). Interestingly, accurate recognition of chronic migraine diagnosis was neither related to training year nor correct recognition of the ICHD-3 beta diagnostic criteria for chronic migraine. Despite accurate individual recognition of episodic migraine and chronic tension-type headache, participants were poor at recognizing that features of these primary headache disorders can co-exist to comprise a uniform diagnosis of chronic migraine. Accurate diagnosis of chronic migraine was improved with use of a lumping strategy to the headache history.