First, you should report your income change to the Marketplace. The Marketplace will determine your new eligibility for premium tax credits, based on your higher income, and adjust the level of subsidy going forward. If you make this adjustment promptly, it’s likely you won’t receive any more advanced premium tax credit during the entire year than you’re eligible for based on your annual income.
As for the new “affordability” of your job-based coverage option, that won’t be taken into account when you file your taxes. As long as the Marketplace determined you were not eligible for affordable job-based coverage when you initially applied for Marketplace coverage and subsidies, that determination will hold for the remainder of the year. The IRS refers to this as a “safe harbor,” and won’t require you to go back and re-compute the affordability of your job-based coverage at year end when you file your taxes.
Browse more questions in the Employer-Sponsored Health Coverage section.