The periodic utilization of three key indicators—casemix, Casemix Index (CMI), and Hospital Base Rate (HBR)—is crucial for maintaining service quality while ensuring operational efficiency in hospitals, particularly within Indonesia's National Health Insurance (JKN) system. This study aimed to analyze factors influencing, and develop strategies for enhancing the performance of, casemix indicators, the Casemix Index, and the Hospital Base Rate at Bali Royal General Hospital over the period 2019–2024. The research was conducted at Bali Royal General Hospital from May to June 2025. Primary data were collected through in-depth interviews and focus group discussions, while secondary data were obtained from the Ministry of Health's electronic claim (e-claim) database, hospital financial reports, and institutional records. This study employed an observational design with a qualitative approach to analyze the performance of casemix indicators, CMI, and HBR for both inpatient and outpatient services. The findings revealed that structural elements (i.e., human resources, materials, machinery, budget, and methods) and process elements (i.e., patient management, coding management, and claims management) collectively determine output elements, identified as casemix indicators, the Casemix Index, and the Hospital Base Rate. Strategic enhancements to these structural elements were found to positively impact patient service processes, improve coding efficiency by up to 50%, and increase claim success rates. Results for the 2019–2024 period were as follows: Outpatient casemix counts were 11,393; 16,037; 32,763; 59,520; 111,193; and 129,423 for the years 2019 to 2024, respectively. Inpatient casemix counts for the years 2019 to 2024 were, respectively: Class 1: 907; 1,321; 2,657; 3,165; 3,829; and 4,014. Class 2: 818; 1,013; 1,800; 2,511; 3,052; and 3,309. Class 3: 205; 539; 1,557; 2,023; 2,646; and 3,038. Casemix Index (CMI) values for the years 2019 to 2024 were, respectively: Outpatient CMI: 0.98, 1.11, 1.16, 1.21, 1.35, and 1.24. Inpatient CMI: Class 1: 1.32, 1.60, 1.84, 1.57, 1.45, and 1.37. Class 2: 1.17, 1.36, 1.58, 1.41, 1.33, and 1.33. Class 3: 1.46, 1.82, 1.67, 1.54, 1.53, and 1.45. Hospital Base Rate (HBR) values for the years 2019 to 2024 were, respectively (currency unit not specified in the original text): Outpatient HBR: 354,393; 333,231; 257,536; 243,675; 226,650; and 238,494. Inpatient HBR: Class 1: 5,257,416; 6,028,120; 5,477,120; 5,970,918; 6,542,667; and 7,082,825. Class 2: 4,449,693; 5,628,665; 4,817,066; 4,993,043; 5,156,750; and 5,563,012. Class 3: 3,616,138; 4,594,204; 3,746,071; 4,325,317; 4,584,260; and 4,789,356. Overall, casemix counts and the Casemix Index exhibited an upward trend annually, with CMI performance exceeding the established standard for Class C private hospitals in Regional Area 2. While the outpatient HBR from 2021 to 2024 fell below the national HBR, the inpatient HBR for Classes 1, 2, and 3 consistently surpassed the national benchmark. Recommended strategies to enhance casemix performance, improve the Casemix Index, and reduce the Hospital Base Rate center on optimizing structural elements. This includes improving human resource competencies, refining methodologies, and increasing the efficiency of machinery, materials, and budget allocation. Furthermore, a rigorous evaluation of process elements—such as patient management, clinical coding accuracy, and claims management procedures—is deemed essential.