Before you start

Private health insurance that explicitly covers treatment in Thailand
The 24-hour assistance number for your insurer, saved offline
Vientiane Rescue (1623) in your phone
A passport you can produce quickly, because the hospital may be in another country

Step-by-step

1
Buy insurance that covers Thailand, not just Laos
Cover limited to Lao facilities is close to useless for anything serious. The policy needs to name Thailand as a treatment territory, and ideally name the Udon Thani and Bangkok hospitals it will bill directly. Check this before you check anything else.
OnlineWho: YouA few daysWide range — see totals
2
Register with a Vientiane clinic for routine care
Internationally staffed clinics in Vientiane, including centres backed by Thai hospital groups, handle general practice, paediatrics, women's health, basic imaging and laboratory work. Register while you are well and find out what they can and cannot do.
In personWho: You~30 minConsultation fees
3
Know your Thailand route in advance
Udon Thani is around ninety minutes from Vientiane and has several hospitals used to foreign patients. Ambulances from hospitals on the Thai side have permission to cross the Friendship Bridge to collect patients from Vientiane, and although the bridge's published hours are 6am to 10pm, officials generally allow crossings outside them for genuine medical emergencies.
OnlineWho: YouBefore you need itFree to plan
4
Save 1623 and tell your household
Vientiane Rescue, on 1623, is the volunteer emergency service that actually responds in the capital — around 200 volunteers, eight ambulances and stations placed near the city's accident hotspots. Published official emergency numbers are inconsistent; this one is the one residents rely on.
Mobile appWho: YouTwo minutesFree
5
Carry your own medical record
Because your care may be split across a Vientiane clinic and a Thai hospital, nobody holds a complete file on you. Keep your own: diagnoses, medications with generic names, allergies, and scans. It saves hours at exactly the moment hours matter.
Mobile appWho: YouOngoingFree

Documents you’ll need

Passport — you may be treated in another country
Insurance certificate naming Thailand as a treatment territory
Insurer's 24-hour assistance number
Your own medical summary and medication list
Vaccination records

Things most newcomers don’t know

Thai ambulances can cross the Friendship Bridge to collect you.

Ambulances operated by hospitals on the Thai side, including in Nong Khai and Udon Thani, have permission to cross the First Thai–Lao Friendship Bridge to collect patients from Vientiane, and the crossing is generally opened outside its 6am–10pm hours for genuine emergencies. This is the mechanism that makes living in Vientiane medically reasonable, and it works far better if you have already established which hospital your insurer will send.

Source: Australian Embassy in Laos medical guidance; U.S. Embassy Vientiane medical assistance information

1623 is the number that answers.

Laos's published emergency numbers are reported inconsistently across sources and some lines do not reliably connect. Vientiane Rescue, founded in 2010 and a 2016 Ramon Magsaysay Award recipient, operates the capital's free volunteer ambulance and rescue service on 1623 from stations positioned near accident hotspots. In a city where the official picture is murky, this is the concrete, verifiable answer.

Source: Vientiane Rescue; Vientiane Times and Ramon Magsaysay Award coverage

A policy that covers only Laos is close to worthless for anything serious.

Vientiane's clinical ceiling is low, and the standard response to a serious case is treatment in Thailand. If your policy's treatment territory stops at the border, you are insured for exactly the conditions you could have paid for out of pocket, and uninsured for the ones that matter. Check the territory clause, then check whether it names the hospitals.

Source: insurer policy documents; community-reported

Keep your passport where you can grab it, because the hospital may be abroad.

Crossing to Udon Thani for treatment is an international border crossing, with all that implies. Residents who keep their passport locked in an employer's safe, or who are between stay-permit renewals, can find the logistics of getting treated considerably harder than the medicine. Know where your passport is at all times.

Source: community-reported

Common mistakes to avoid

Buying insurance whose treatment territory stops at the Lao border
Relying on a published official emergency number instead of saving 1623
Not knowing which Thai hospital your insurer would send you to until you need one
Being separated from your passport when a border crossing becomes a medical necessity
Assuming a Vientiane clinic can handle a case that needs a tertiary hospital

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