Legally? No - the law requires insurance on the vehicle, not the person. Practically? Riding in Vietnam without personal cover is one of the most expensive risks a visitor can carry. Both answers are true.
What the law requires
Compulsory third-party insurance on every registered motorbike. It comes with any legal rental (ask to see the certificate), and it covers damage the bike causes to others. That is the whole legal requirement - there is no legal obligation on you personally to hold medical or travel insurance.
Why you need it anyway
Vietnamese hospital treatment for a road accident is paid for by the patient: your treatment, your evacuation, your flight-change, your months of recovery. The compulsory insurance on the bike does not pay a dong of it. Personal travel or medical insurance is the only thing that does - and a motorbike accident is one of the more statistically plausible claims a visitor in Vietnam can make.
The exclusion that voids most claims
Read the two-word clause: “licensed riding.” Most travel policies that cover motorbikes cover riding with a licence valid in the country. If your licence route is not valid in Vietnam - no 1968-convention IDP behind a real motorcycle licence, or no Vietnamese licence - the typical policy excludes exactly the accident you are imagining. Sort the licence and the insurance together or neither one actually protects you. The same logic applies to alcohol: zero tolerance for riders, and a claim after drinking is void in every policy.
What to check, in five questions
- Does the policy cover riding a motorbike at all (many exclude two-wheelers)?
- Does it cover the engine size you are renting?
- Does it accept my licence route as valid in Vietnam?
- What are the medical limits, and does it include evacuation?
- Does it cover personal liability beyond the bike’s compulsory insurance?
The bottom line
The rental gives you a legal, insured bike. It does not give you an insured self. The bike’s insurance is the shop’s responsibility; your insurance is yours. Both articles above split exactly what each covers.