MIPS (Merit-based Incentive Payment System) is the default Medicare Quality Payment Program pathway for most eligible clinicians who are not sufficiently participating in an Advanced APM. In practice, if a clinician is MIPS-eligible and does not meet reporting requirements (or performs poorly), Medicare applies a negative payment adjustment---so ''non-participation'' effectively carries financial risk. APMs (Alternative Payment Models), especially Advanced APMs, are not automatically required for all clinicians; they are model-based arrangements (often tied to specific payers, contracts, patient populations, and risk/quality terms) that clinicians typically enter through organizational participation decisions. A key operational difference emphasized in outpatient CDI education is that MIPS performance hinges on accurate, complete documentation supporting quality measures and resource use across a broad clinician population, whereas APM participation depends on being in a qualifying model and meeting its participation/threshold rules. Therefore, MIPS functions as the required/default track with potential penalties, while APM participation is elective and model-dependent.