Do US citizens need a visa for the UAE

No, not in advance. American citizens with a regular passport are issued a visa on entry to the UAE. It allows up to 90 days of stay, which cannot be renewed, taken either in one trip or across several, within a 180 day window counted from the day you first arrive.

U.S. citizens are not required to apply for a visa before traveling to the UAE. A visa will be issued upon entry, allowing a maximum stay of 90 days non-renewable, whether continuously or intermittently, within 180 days calculated from the date of first entry.

Embassy of the United Arab Emirates in Washington, DC

The embassy also lists what to have with you before departure:

• A passport valid for at least six months beyond the date you expect to arrive.
• A round trip ticket, or a confirmed ticket onward to another destination.
• An awareness that going past the 90 days costs AED 50 for each extra day.

GDRFA publishes a stay calculator, which is the sensible way to work out where you stand if you have made several trips inside the same 180 days.

What this does not mean

Ninety days on arrival is not a residence permit. It does not let you work, sponsor a family member or sign a residential tenancy, and it is not extended by leaving and coming straight back, because the allowance is counted across the whole 180 day window rather than per trip. This answer also covers regular US passports only; diplomatic and official passports follow a different route.

If the plan is to stay and work, the residence route and its costs are in our guide to UAE residence visa costs, and the long term option in our Golden Visa guide.

Sources: UAE Embassy in Washington, DC, Visas for US Citizens (entry rule, 90 in 180, passport validity, ticket, AED 50 per day); GDRFA Dubai, visa calculator.