EDITED (see 2 additional questions on bottom) Regarding the repayment of Excess Advance Payment of the Premium Tax Payment, a client had marketplace health insurance and correctly estimated their income based on their current circumstances when they applied. They had marketplace insurance for Jan, Feb, Mar 2024. In April started a full time job, got health insurance through employer and immediately canceled marketplace. Annual income was higher than estimated but the first quarter wasn't.  They have a penalty for the excess advance payment. How would a taxpayer know what would happen in the future? Can someone explain how someone would be able to avoid this penalty? I am clearly struggling to understand it. 

Why was this penalized when the proper protocol was followed? Is there logic behind this regulation? 

Thanks.