Before you start

Understand you are NOT covered by Thailand's universal '30-baht' scheme (UCS) — that's for Thai nationals
A funding plan: self-pay, employer Social Security (SSO), or private/international insurance
If on an O-A or LTR visa: a health-insurance policy meeting the visa's minimum cover (a visa condition, not optional)
Passport; work permit if you're going the SSO route

Step-by-step

1
Pick how you'll pay: self-pay, SSO, or private insurance
Thai UCS doesn't cover foreigners. If you're employed with a work permit, your employer enrols you in Social Security (SSO) — ~5% of salary (employee share ≈ 750 THB/mo) — giving coverage at one designated hospital. Everyone else self-pays or buys private cover. Retirees and nomads typically insure privately.
Via employerWho: You (or employer for SSO)SSO: enrolled at hiring; insurance: days to buySSO ≈ 750 THB/mo (employee share); self-pay otherwise
2
Choose a private insurer (and check your visa's requirement)
Nomads often use international plans (SafetyWing, Cigna Global); residents and retirees use Thai insurers — Pacific Cross, AXA Thailand, Luma. Good cover runs ~20,000-60,000 THB/yr (~US$550-1,650) depending on age and limits. O-A visas require health insurance (historically ≥40,000 THB outpatient / 400,000 THB inpatient cover); the LTR visa requires US$50,000 cover or a deposit. Verify the current floor before you buy.
OnlineWho: YouA few days to underwrite/issue~20,000-60,000 THB/yr (US$550-1,650)
3
Register with a Chiang Mai hospital and keep a pharmacy nearby
Open a patient file at a private hospital — Bangkok Hospital Chiang Mai, Chiang Mai Ram, or Lanna (international desks, English-speaking); McCormick is well-regarded and cheaper; CMU's Sriphat Medical Center / Maharaj Nakorn (Suandok) is the top university hospital, lower-cost but busier. A walk-in GP visit is ~500-1,000 THB; a specialist ~1,000-2,000 THB. Pharmacies are everywhere and sell many meds OTC cheaply.
In personWho: YouSame day for registration / walk-inGP ~500-1,000 THB; specialist ~1,000-2,000 THB
4
Prepare for the burning season and know the emergency numbers
Roughly February-April, agricultural and forest burning push Chiang Mai's PM2.5 to among the world's worst — a real health risk (respiratory, cardiac). Get a HEPA air purifier per room, keep N95/KN95 masks, watch a PM2.5 app (e.g. IQAir), and budget the option to leave town as many residents do. Save 1669 (national EMS/ambulance) and 191 (police); 1669 dispatch may have limited English, so a private hospital's own ambulance line is often faster.
In personWho: YouSet up before FebAir purifier ~5,000-15,000 THB; masks cheap

Documents you’ll need

Passport
Work permit (for SSO enrolment, if employed)
Insurance policy / card (international or Thai insurer)
Proof of health insurance meeting the visa minimum (O-A / LTR applicants)
Any prior medical records / prescriptions you rely on

Things most newcomers don’t know

The famous '30-baht' universal healthcare is not for you.

Thailand's UCS covers Thai nationals; as a foreigner you self-pay or insure regardless of how long you've lived here. Employed foreigners get SSO instead — budget for one of these, don't assume you'll be covered like locals.

Source: NHSO / Ministry of Public Health

Burning season (Feb-April) is the real Chiang Mai health story.

For weeks, PM2.5 routinely makes Chiang Mai one of the most polluted cities on earth — a genuine cardiopulmonary risk, not an inconvenience. Plan air purifiers, N95 masks, and the budget/flexibility to leave, the way many long-term residents do.

Source: air-quality monitoring (IQAir) / provider

Self-paying at a private hospital is often cheaper than you'd guess.

Chiang Mai is a medical-tourism hub: a GP visit is ~500-1,000 THB and a specialist ~1,000-2,000 THB at private hospitals, with no insurance paperwork. For minor issues, paying cash at McCormick or CMU's Sriphat can beat a high-deductible policy.

Source: Chiang Mai hospital tariffs (provider)

Common mistakes to avoid

Assuming the '30-baht'/UCS scheme covers you — it doesn't; foreigners aren't eligible
Buying a policy without checking your visa's required minimum cover (O-A insurance rules; LTR's US$50,000) and getting refused at renewal
Underestimating burning season — arriving without an air purifier or plan when PM2.5 spikes in Feb-April
Expecting pre-existing conditions to be covered — Thai private policies routinely exclude them and premiums climb steeply with age

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