Updated October 18, 2026. Quick answer: Line 1 is your tax family size, the number of people in your tax family counting yourself. You work it out from your tax return: you, your spouse if filing jointly, and the dependents you claim. The number is then used to pick the federal poverty line on line 4.
Related reading on this site: IRS Publication 974.
What line 1 asks for
The form’s caption reads “Tax family size. Enter your tax family size. See instructions”. The instructions say “Enter on line 1 your tax family size.” They define the term this way: “Your family size equals the number of qualifying individuals in your tax family (including yourself).” This page is part of the Form 8962 walk-through.
Who is in your tax family
The instructions say to “Determine the number of individuals in your tax family using your tax return.” They continue: “you, your spouse if you are filing a joint return, and your dependents.”
Two of the building blocks are “Your dependents whom you claim on your 2025 tax return.” and “Your spouse if filing jointly and your spouse can’t be claimed as a dependent on someone else’s 2025 tax return.” On how dependents are claimed, the instructions note “Listing your dependent by name and social security number (SSN) or individual taxpayer identification number (ITIN) on your tax return is the same as claiming them as a dependent.” The dependents and filing status on the return are explained at Form 1040 line by line.
When you or your spouse are left out
The instructions say that if you checked the box “Someone can claim you as a dependent” on your tax return, or the matching box for your spouse on a joint return, “you or your spouse is not included in the tax family size calculation for purposes of Form 8962, line 1.”
There is also a case for policies shared with another tax family: “If you and the other taxpayer agree that they will reconcile all APTC paid and you are not taking the PTC, enter-0on line 1.” The follow-on steps are on the lines 9 and 10 page.
Where the number comes from
It comes from your tax return and from who you claim on it, not from the Marketplace statement. The covered people on the statement are explained on the Form 1095-A Parts I and II page, but the instructions tell you to use your return to count the family.
Where it goes next
The number is used for the poverty line on line 4. The instructions tell you to use the amount “for the family size you entered on line 1 of Form 8962.” That step is on the lines 3 to 6 page. The rest of Part I follows: lines 2a and 2b for modified AGI.
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 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.
Common mistakes
- Counting someone who is not a claimed dependent. The instructions build the family from “Your dependents whom you claim on your 2025 tax return.”
- Counting yourself when someone else can claim you. The instructions say “you or your spouse is not included in the tax family size calculation for purposes of Form 8962, line 1.”
- Assuming a dependent is only someone you name in conversation. The instructions say “Listing your dependent by name and social security number (SSN) or individual taxpayer identification number (ITIN) on your tax return is the same as claiming them as a dependent.”
Related: Form 1040 line by line, Form 1095-A Parts I and II, and Form 1040.
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.