Updated October 18, 2026. Quick answer: Part IV is only for a health plan shared with someone outside your tax family. Lines 30 through 33 each record one allocation: the policy number, the other person’s SSN, the months, and the percentage of premiums, second lowest cost silver plan premium and advance payment you take on. Line 34 asks whether you are finished.
When Part IV applies
The instructions on line 9 say “You need to allocate policy amounts (enrollment premiums, SLCSP premiums, and/or APTC) on a Form 1095-A between your tax family and another tax family if:” the policy covered at least one person in your tax family and at least one in another, and one of the Forms 1095-A does not match the real tax families. Part IV says “See Line 1 and Line 9, earlier, to determine whether you need to complete Part IV.” Line 9 is explained on the lines 9 and 10 page, and the family size on the line 1 page. The shape of the whole form is on the Form 8962 line by line guide page.
The four allocation situations
The instructions sort shared policies into four situations, and Table 3 under line 9 decides which one fits. Allocation Situation 1 is for divorce: “You and your former spouse must allocate policy amounts on your separate returns to figure your PTC and reconcile it with your APTC if both of the following apply.” Allocation Situation 2 is for people married at year end but filing separately: “You and your spouse must equally allocate (50% to each spouse) certain policy amounts if all of the following conditions are met.”
Allocation Situation 3 is for a policy with no advance payment: “the enrollment premiums are allocated in proportion to the SLCSP premium that applies to each taxpayer’s coverage family.” Allocation Situation 4 is the catch-all: “Complete Part IV using the rules in this section if you need to allocate policy amounts and Allocation Situations 1 through 3 do not apply.” Each situation has its own examples in the instructions. Read the one that matches your facts.
For the first situation, the instructions add that “you must allocate all three amounts using the same percentage.” For the fourth, if the two taxpayers disagree, “each taxpayer’s allocation percentage is equal to the number of individuals enrolled by one taxpayer who are included in the tax family of the other taxpayer” divided by the total number of people enrolled in the policy.
Lines 30 to 33, column by column
Each of lines 30 through 33 is one allocation. Column (a): “Enter the Marketplace-assigned policy number from Form 1095-A, line 2.” The instructions add “If the policy number on the Form 1095-A is more than 15 characters, enter only the last 15 characters.” Column (b): “Enter the SSN of the taxpayer with whom you are allocating policy amounts.” Column (c): “Enter the first month you are allocating policy amounts.” Column (d): “Enter the last month you are allocating policy amounts.” The policy number is on the Form 1095-A section covered on the Form 1095-A parts I and II page.
Columns (e), (f) and (g) hold the percentages. For column (e), the premiums: “Enter your allocation percentage as a decimal rounded to two places”. Column (f), the SLCSP premium, is used in Allocation Situation 1 and Allocation Situation 4; the instructions say “In all other situations, leave column (f) blank because you do not allocate the applicable SLCSP premium reported in those situations.” Column (g) is the advance payment, and the instructions say “If your allocation situation requires you to allocate the APTC on Form 1095-A, lines 21 through 32, column C, enter your allocation percentage for that policy in column (g).” Otherwise leave it blank.
Line 34: have you finished
The form asks “Have you completed all policy amount allocations?” The instructions say “If you have completed your required allocations of policy amounts shown on Forms 1095-A using lines 30 through 33” you check yes. For more than four, the instructions say “If you must make more than four allocations of policy amounts shown on Forms 1095-A” you check no and “attach a statement to your return providing the information shown on lines 30 through 33, columns (a) through (g), for each additional allocation.”
Where the number comes from
The policy number, premium, SLCSP premium and advance payment come from your Form 1095-A; the other taxpayer’s SSN and the agreed percentage come from you and that person. On the SSN, the instructions say “This SSN may or may not be reported on your Form 1095-A, depending on your relationship to the other taxpayer.” When the allocation is done, the form says to “Multiply the amounts on Form 1095-A by the allocation percentages entered by policy.” It then says “Add all allocated policy amounts and nonallocated policy amounts from Forms 1095-A, if any, to compute a combined total for each month.”
Where it goes next
The combined monthly totals are entered in the monthly rows of Part II, which is covered on the lines 11 to 23 page. The instructions for column (a) say “If you completed Part IV for any Form 1095-A, add the monthly premium amounts allocated to you”. For the effect on line 10 and line 11, read the line 10 instructions on the lines 9 and 10 page.
Edition and line numbers
This page reads the 2025 Form 8962 and its 2025 instructions, the current files irs.gov served on 2026-10-18. They are the files for the tax year 2025 return, filed in 2026. The form header says “Attach to Form 1040, 1040-SR, or 1040-NR.” Check the tax year printed on the form you are filling in and use the line numbers on that year’s form, because a different year’s form can number or word its lines differently. The whole form is walked through on the Form 8962 line by line guide page.
Common mistakes
- Using different percentages for the three amounts. In the divorce situation, “you must allocate all three amounts using the same percentage.”
- Entering a percentage as a whole number. The instructions say “Enter your allocation percentage as a decimal rounded to two places”.
- Copying a long policy number in full. The instructions say “If the policy number on the Form 1095-A is more than 15 characters, enter only the last 15 characters.”
Related: Form 1095-A parts I and II, Form 1095-A column A, Form 1095-A column B, Form 1095-A column C, and Form 1095-A void, corrected or missing.
Sources
- Instructions for Form 8962, Premium Tax Credit (PTC) (2025): https://www.irs.gov/pub/irs-pdf/i8962.pdf
- Form 8962, Premium Tax Credit (PTC) (2025): https://www.irs.gov/pub/irs-pdf/f8962.pdf
Read from the IRS documents linked above on October 18, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.