The Community-acquired Pneumonia (CAP) guidelines from the American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA) were established utilizing systematic reviews to inform every suggestion, as recommended by the Institute of Medicine Standards for Trustworthy Guidelines. A recent research suggested that the Convergence of Opinion on Recommendations and Evidence (CORE) procedure, based on expert consensus, can provide recommendations consistent with those based on systematic reviews. For a study, researchers wanted to determine how effective the CORE approach would be in developing the ATS/IDSA CAP standards. Experts in CAP who were not on the guideline panel and had no prior knowledge of the guideline’s systematic reviews or recommendations were enlisted to help with the CORE process, answering the same questions that the guideline panel had. The guideline suggestions were comparable to the recommendations produced from the CORE process. The quality of evidence, the strength of the suggestion, and the consistency of the course of action were all determined. The CORE method produced recommendations for 20 of 31 (65%) questions, using a criterion of 70% of experts adopting the same course of action to generate a recommendation. 19 of the 20 CORE-derived recommendations (95%) agreed with the guideline recommendations (kappa agreement 0.88, 95% CI.64–1.00). The strength of recommendations (58%) and the quality of evidence (58%) had less agreement (42%). If the CORE process had been implemented, just 11 systematic reviews would have been required instead of 31, and the recommended courses of action would have had little impact.