Hello, I am e-filing my 1040, how can I edit form 8962 online to use the alternative calculation for year of marriage?

To use the alternative calculation for the year of your marriage:

1. Click Deductions and Credits
2. Scroll down to Medical and Click Show More
3. Click Start or Revisit next to the ACA
4. Once you enter the 1095-A or verify the information that has already been entered you will come to a screen that says Let us know if these situations apply to you. Click I got married in 2021 and answer the two follow-up questions.

Once you have entered that information, TurboTax will automatically apply the calculation that yields a better result. 

Hello, 

I entered in my month of marriage however it did not update the calculation. It also didn’t ask the months from when to when an alternative calculation should be used (as it does on the actual 8962 form) or my Wife’s household income prior to marriage. Any advice?

In many cases, the Alternative Calculation does NOT reduce the repayment.  TurboTax automatically recalculates, based on your input, the Alternative Calculation if it applies to your return.  If the Alternative Calculation does not affect your return you will not see anything different on  Form 8962. 

Premium tax credits are based on an ACA-specific version of modified adjusted gross household income (MAGI). Married couples have to file a joint tax return in order to qualify for a premium tax credit.  If you get married mid-year, your premium tax credit eligibility is going to be based on your total  combined income

When two people get married, their household income is the combined total of their individual incomes. However, the poverty level for a household of two is not double the poverty level for a household of one. This combined income of the two individuals may put them into a much higher percentage of the poverty level than they each had prior to the marriage. Subsidy amounts are based on how a household's income compares with the poverty level, this can result in a considerable amount of excess subsidy having to be repaid to the IRS.

This is particularly true if the household's total income ends up being above 400% of the poverty level. Even though the American Rescue Plan does allow for subsidies above that level through the end of 2022, there is no cap on excess subsidy repayments for households with income above 400% of the poverty level.

This link to IRS Publication 974 (2020), Premium Tax Credit (PTC) has additional information you may find useful.