Before you start

Missouri residence
Income information for subsidy or MO HealthNet eligibility
An SSN or ITIN, plus immigration documents for marketplace eligibility categories
A qualifying life event if enrolling outside the annual open enrolment window

Step-by-step

1
Enrol in your employer's plan within the new-hire window
Typically 30 days from your start date. Compare the deductible and out-of-pocket maximum rather than the premium alone.
Via employerWho: YouFirst 30 days of employment
2
Check MO HealthNet eligibility before anything else
Missouri covers adults up to 138% of the federal poverty level with no premium, under the expansion voters approved in 2020. Newcomers on a modest first income, or between jobs, frequently qualify and do not think to look.
OnlineWho: You
3
Without an employer plan, use HealthCare.gov
Missouri does not run a state exchange, so the federal marketplace is the route. A permanent move to Missouri is itself a qualifying life event opening a special enrolment period.
OnlineWho: You
4
Check which hospital system your plan actually covers
BJC, SSM Health and Mercy are separate networks with separate contracts, and a narrow-network marketplace plan can exclude one almost entirely. In a metro where BJC and Washington University hold most of the tertiary care, that is the most consequential plan question.
OnlineWho: You
5
Remember the state line if you live in Illinois
The metro straddles the Mississippi. If you live on the Illinois side and work in Missouri, your Medicaid, marketplace and children's health programme are all Illinois's, on Illinois's rules and its own state-run exchange — not Missouri's. Employer plans usually cover both sides, but public programmes never do.
OnlineWho: You
6
Learn the urgent care versus emergency room distinction
An emergency room visit for something a clinic could treat can cost thousands even when insured. All three systems run urgent-care sites across the metro at a fraction of the cost.
In personWho: You

Documents you’ll need

Proof of Missouri residence
Income documentation for subsidies or MO HealthNet
SSN or ITIN
Immigration documents establishing lawful presence
Evidence of losing prior coverage, if using a special enrolment period

Things most newcomers don’t know

Missouri's Medicaid expansion sits in the state constitution, not in a statute.

Voters approved it as a constitutional amendment in August 2020, which is why it survived a subsequent attempt to leave it unfunded and why it cannot simply be repealed by the legislature. Practically it means the expansion group is stable — a real difference from a newcomer's point of view compared with the non-expansion states in this app.

Source: Missouri Department of Social Services

Living across the river puts you under a completely different health system.

The metro spans Missouri and Illinois. Illinois runs its own marketplace and its own Medicaid rules, and residency for public programmes follows where you sleep, not where you work. People who take a cheaper apartment in Belleville or Edwardsville sometimes do not realise their entire public-coverage position changed with the postcode.

Source: HealthCare.gov

Which of the three systems your plan covers matters more than the deductible.

BJC, SSM and Mercy are separate networks. Because BJC and Washington University concentrate most of the region's specialist and academic medicine, a cheaper narrow-network plan can quietly rule out the hospital your consultant works at. Check the specific hospital against the network list before enrolling, not the insurer's brand.

Source: community-reported

Lawfully present immigrants can qualify for marketplace subsidies below the poverty line.

Because lawfully present non-citizens are often barred from Medicaid for their first five years, federal rules let them claim marketplace subsidies at incomes below 100% of the federal poverty level. If MO HealthNet refuses you on the five-year bar, go back to HealthCare.gov rather than assuming nothing is available.

Source: HealthCare.gov — immigrants and the marketplace

Common mistakes to avoid

Choosing a marketplace plan without checking which hospital system it actually includes.
Missing the 30-day new-hire enrolment window and waiting a year.
Applying to Missouri programmes while living on the Illinois side of the metro.
Losing MO HealthNet at annual renewal by not responding to post.
Using an emergency room for something urgent care handles at a tenth of the price.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.