For a study, it was determined that the diagnostic method for neuroendocrine cell hyperplasia of infancy (NEHI), an essential manifestation of children’s interstitial and diffuse lung disease, has evolved. There has never been a study of the prevalence of comorbidities in the NEHI that could affect treatment. A retrospective chart study of 199 deidentified NEHI patients from 11 centers was conducted by Researchers to test a previously unpublished NEHI clinical score. Researchers used descriptive statistics to analyze data obtained in a centralized Research Electronic Data Capture registry. The majority of NEHI patients were men (66%). For all patients from included sites, the NEHI Clinical Score had a sensitivity of 87% (95% CI, 0.82–0.91), and 93% (95% CI, 0.86–0.97) for those with complete scores (e.g., no missing data). The results were comparable when they confined the cohort to the 75 patients diagnosed by lung biopsy (87%; 95% CI, 0.77–0.93). About 51% of the patients with comorbidities had gastric reflux, 35% had aspiration or were at risk for aspiration, and 17% had immune system abnormalities, according to the study. The NEHI Clinical Score is a sensitive measure for evaluating NEHI clinically, although its specificity has yet to be determined. Because these can affect the child’s clinical picture and treatment, clinicians should look for comorbidities in NEHI patients, including gastric reflux, aspiration, and immune system abnormalities.