Split your 1095-A into two, one for January through May, and the other for June through the end of the year.
For January through May, enter the Form 1095-A exactly as it appears for those months. Select the allocation box, enter your first son's social security number who stopped receiving coverage in May, select January through May as the dates, and for the allocation percentage, enter the percentage you have worked out with your two children. You must claim the same percentage of monthly premiums, SLCSP, and tax credit received, but you can claim as much or as little of the total as you want. If you are splitting it evenly, you can claim 33% of each. Your two sons will also claim 33% (one of you must claim 34% actually).
Enter Form 1095-A using the information from June through December. Select the allocation box, enter your other son's SSN, and select June through August as the dates. If you are splitting it evenly, each of you will claim 50% of the monthly premium, SLCSP, and tax credit.
Again, you do not have to split it evenly. As long as all three of you agree to it, you can allocate it however you choose.
Your first son will only claim his percentage of Form 1095-A for January through May. He will enter it exactly as it appears for those months. He does not need to include the June - December information. He will enter your social security number, the dates, and his allocation percentage.
Your second son will also need to fill out two 1095-As, one for January through May and one for June through August since his allocation percentage will be different. He will use your SSN on both and enter only the months that pertain to him for each form.
