You are ready to sign up for Marketplace coverage, you sit down to apply, and twenty minutes in you are hunting for a pay stub or a policy number you do not have. It is the most common way an application stalls. The good news: the documents needed for your HealthCare.gov application fit on one short list, and you can gather everything before Open Enrollment even starts. This guide walks through the Marketplace's own checklist, explains why each item matters, and covers what happens if the Marketplace later asks you to send proof.
The official checklist: what every application asks for
The Marketplace publishes an application checklist, and it is short. Before you start, have this information for your household:
- Who in your household is applying together. The application asks about household size even for members who do not need coverage, because financial help is based on the whole tax household.
- Home and mailing addresses for everyone applying.
- Social Security numbers and birth dates for everyone applying.
- Document information for legal immigrants and naturalized citizens (more on this below).
- How you plan to file your taxes for the year you want coverage.
- Employer and income information for every member of your household, such as pay stubs or W-2s, plus your best estimate of household income for the coverage year.
- Policy numbers for any health plans currently covering members of your household.
- Information about any job-based plan you or a household member is eligible for, even if you do not plan to enroll in it.
- Notices from your current Marketplace plan that show your plan ID, if you already have Marketplace coverage.
- The name and information of your agent, broker, or assister, if someone is helping you apply.
Income records: the part worth getting right
The application does not ask what you earned last year so much as what you expect to earn during the year you are buying coverage for. That estimate drives your premium tax credit, so a careless number costs real money in one direction or the other: estimate too low and you may owe money back at tax time, estimate too high and you pay more than you need to every month.
Recent pay stubs, last year's tax return, and W-2s are the raw material. From there, build an honest forward-looking estimate that accounts for raises, job changes, or self-employment swings you can already see coming. If your income changes after you enroll, report it rather than waiting for tax season; our guide on how to update your income on HealthCare.gov walks through exactly how and why.
Job-based coverage: the worksheet people skip
If anyone in your household could get coverage through a job, including through a spouse's or parent's employer, the Marketplace needs details about that offer even when nobody intends to take it. Whether a job-based offer is considered affordable affects whether you qualify for savings on a Marketplace plan.
HealthCare.gov provides an Employer Coverage Tool, a one-page worksheet the employer helps fill out, covering what the plan costs and what it covers. Downloading it and handing it to the HR department before you apply is faster than discovering mid-application that you need answers only your employer has.
Immigration documents and Social Security numbers
Everyone applying for coverage is asked for a Social Security number and birth date. Lawfully present immigrants and naturalized citizens are asked for document information instead of or alongside an SSN, such as the type of immigration document and its ID numbers. Have the physical documents in front of you when you apply so you can copy numbers exactly; a single transposed digit is a common cause of the verification requests described below.
Only people applying for coverage need to provide this. Household members who are not applying are counted for household size and income, but are not required to document citizenship or immigration status.
What a data matching issue is, and what to send if asked
After you apply, the Marketplace checks your answers against its data sources. When something does not line up, such as income, citizenship, or immigration status, you get what the Marketplace calls a data matching issue, also known as an inconsistency. It is not an accusation. It simply means you need to send documents that confirm what you entered.
Your eligibility notice tells you what to send and lists your deadline; HealthCare.gov says that in most cases you have at least 90 days to clear it up. The fastest route is uploading documents to your HealthCare.gov account. You can also mail photocopies, never originals, with the bar code page from your notice. The Marketplace does not accept documents by email or fax. Take the deadline seriously: if you are enrolled and the issue is not resolved in time, you could lose your coverage or your savings.
Applying with an agent? One more thing to have ready
If a licensed agent helps you apply, keep your phone nearby. New for 2027, the federal Marketplace requires you to approve your agent electronically, usually through a one-time code or link sent to your phone or email, before they can act on your application. Our guide to Marketplace agent authorization explains how the approval works and how to tell a real request from a scam.
On timing: HealthCare.gov lists Open Enrollment for 2027 coverage as November 1, 2026 through January 15, 2027, with December 15, 2026 the deadline for coverage that starts January 1. Those dates are tied to a court ruling the federal government has appealed, so see our Open Enrollment 2027 guide for the current schedule before you plan around a date.
Gathering documents is the boring half of enrolling; choosing well among the plans is the half that pays off. If you would like a licensed agent to review your options with your checklist in hand, request a quote and we will walk through it together, no obligation.