Objective. This research aimed to determine the in-patient expenditure of COVID-19 adult patient s and their out-of-pocket (OOP) payments at the University of the Philippines-Philippine General Hospital (UP-PGH) after the new PhilHealth case rate coverage was instituted last 15 April 2020. It also intended to present the preliminary data on the expenses incurred by COVID patients during the initial phase of the pandemic in the country. Methods. This study was a retrospective chart review of admitted COVID-19 patients aged 19 years old and above from 15 April to 14 August 2020 at UP-PGH that availed of PhilHealth COVID-19 case rate benefits package (C19C1-C4). Data were analyzed to extract overall expenses, out-of-pocket (OOP) charges, cost centers utilization, and other hospitalization expenditure sources. Results. Of the 691 COVID-19 patients included during the study period, 55.72% were male, mostly belonging to the 61-70 age range with a median age of 58. The average in-hospital stay was 14.20 days, and 76.99% were under charity services, with the moderate (42.84%) and mild (25.33%) pneumonia cases accounting for 68.17% of the admissions. Total hospital expenses clustered around Php51,000 to 200,000 (~USD 1,041 to 4,156), most spending between Php101,000 to 150,000 (~USD 2,078 to 3,118). The top three cost centers and expenditure sources were pharmacies, personal protective equipment (PPE) usage, and laboratory. The average OOP payment for patients less than 60 years old was higher, ranging from Php 25,899 to Php 44,428.63 (USD 538 to USD 924.44) compared to patients older than 60 (Php4,005.60 to Php 32,920.20 ~ USD 83.35 to 684.98). The most OOP charges were for the age group 19-30, amounting to Php 44,428.63 (USD 924.44). Conclusion. Preliminary findings of this study gave an actual representation of the expenses of COVID-19 patients, which can guide future utilization of the national health insurance during unexpected pandemics. Early price regulation of new therapeutic interventions, diagnostic tests, and medical supplies, e.g., PPEs, disinfectants, air filters, are measures that can be implemented.