Causes for chronic cough? (tested negative for asthma, allergies, etc. and my gerd is controlled with meds.)

Chronic cough: Could still be a component of non-allergic rhinitis with post-nasal drainage; cough variant asthma which typically shows normal spirometry but improves with treatment. Could also be medication-induced. And even your gerd treatment might still be suboptimal.

Cough: Hello. A chronic cough can be caused by a number of etiologies. As you mentioned, you have had a good work up so far. Other suggestions would be to review your medications, have an endoscopic evaluation of your vocal cords then see a pulmonary doctor.