This dissertation investigates the interrelationships between a client's non-GAAP earnings disclosures, financial health (profit and loss status), and the external auditor's assessment of the client's going concern status. This dissertation comprises two essays. Essay 1 examines the informativeness and the quality of non-GAAP earnings disclosures in profit and loss firms separately. Using a large sample of non-GAAP earnings voluntarily disclosed by managers, I find that the informativeness and the quality of non-GAAP earnings vary in firms cross-classified by GAAP loss status and non-GAAP loss status. I also find that loss firms have higher quality non-GAAP exclusions relative to profit firms, although the expenses excluded by both profit and loss firms are associated with firms' future performance. Further, I posit and find that profit firms which voluntarily disclose non-GAAP losses have high-quality exclusions, while other non-GAAP reporting profit firms have low-quality exclusions. Having found that non-GAAP earnings in loss firms is opportunistic to some extent, I next study, in Essay 2, whether auditors understand the implications of low-quality non-GAAP reporting in these firms. Specifically, I examine 1) whether non-GAAP earnings disclosures are associated with the propensity of the auditor's going concern issuance to loss firms, and 2) whether non-GAAP earnings disclosures …