The National Mah Jongg League: What It Is and What It Does

Behind every American Mahjong game sits one organization most players know by its initials: the NMJL, or National Mah Jongg League. It's the reason the game is played the same way from a New York apartment to an Arizona clubhouse. Here's who they are and what they actually do.

Where it started

The League was founded in 1937 in New York City, when a group of women set out to bring order to a game that was being played a dozen different ways. Their goal was standardization, one shared set of rules and winning hands so that any four players could sit down and play the same game. It began with a small handful of charter members and has since grown into an organization with hundreds of thousands of members across the country.

That origin is also a piece of American cultural history. The game took particularly deep root in Jewish-American communities, where it became a fixture of friendship and connection passed down through generations, a story we touch on in what is mahjong.

What the League does

Three things, mainly:

• It sets the rules. The NMJL defines how American Mahjong is played, which is why the game is consistent wherever you go.
• It publishes the card. Every year the League issues its official card of legal winning hands, the document at the center of every game. We cover it in the American Mahjong card, explained.
• It gives back. The League is a nonprofit, and a portion of card sales goes to charity, including major organizations in health and medical research. Buying your card quietly supports good causes.

How you become a member

This part surprises people: membership comes with the card. When you buy the annual card directly from the League, you're a member for that year, there's no separate application. It's about $14 for the standard card and $15 for large print, prices set by the League and subject to change.

Is the NMJL the only card?

It's the best-known and most widely played, but not the only one. Other organizations publish their own cards that follow similar conventions, so if you hear about a different card, that's why. For the overwhelming majority of American players, though, "the card" means the NMJL card.

Frequently asked questions

What is the National Mah Jongg League?

A nonprofit organization, founded in 1937, that standardizes the rules of American Mahjong and publishes the official annual card of winning hands.

How do I become a member of the NMJL?

Buy the annual card directly from the League. Membership for the year is included with the purchase, no separate sign-up required.

Does the National Mah Jongg League give to charity?

Yes. As a nonprofit, it directs a portion of card sales to charitable organizations, so playing by the card supports good causes.

Is the NMJL card the only mahjong card?

No, other groups publish cards with similar conventions, but the NMJL card is by far the most widely used in American Mahjong.

Ready to use the card? See how to read the mahjong card, or get this year's in our 2026 card guide.