(NEXSTAR) – Over a 10-year period, the U.S. Mint produced some of the most commonly collected coins – the 50 State Quarters. While each state was honored with a quarter-dollar piece, some may be easier to find these days than others.

Just as the name implies, a separate quarter was minted for every state during the program, which ran from 1999 to 2008, according to the U.S. Mint. Every year, five new quarters were issued, following the order in which the states ratified the Constitution or were admitted into the Union.

On the reverse of each is a unique design of state features or iconic moments in history. The Kansas quarter, for example, features a buffalo and sunflowers – the state animal and state flower, respectively. New York’s quarter features the state, the Statue of Liberty, and the slogan “Gateway to Freedom,” a nod to Ellis Island.

In many states, governors called on residents to submit design concepts and an advisory group was appointed to oversee the process. In 33 states, the governor selected the final design and in 17, citizens made the selection.

Though every state was honored with a quarter, the Mint produced more of some than others.

“The Mint produced [the quarters] to demand in concert with the Federal Reserve,” a spokesperson from the Mint tells Nexstar.

More of the quarters released early in the program were released. A report from the Mint points to Y2K-related concerns in the late 1990s, followed by a slowing economy in 2001 for the production differences.

In total, the Mint produced and shipped 34.3 billion quarters during the 50 State Quarters Program. During the program, the Mint’s average annual mintage reached 3.5 billion quarters, 135% more than the average production during the previous years “to fulfill rising demand.”

At least 400 million of each quarter was minted, Mint records show. For some, especially along the East Coast, more than 1 billion were minted.

You have a better chance of finding Virginia quarters than any others – Mint records show nearly 1.6 billion were put into circulation. Only seven other state quarter designs had more than 1 billion issued: Connecticut, South Carolina, New York, Maryland, New Hampshire, Massachusetts, and North Carolina.

While many state quarters remain in circulation, according to the Mint, some may be harder to find. A dozen – primarily states in the Midwest and the South – had less than half a billion quarters put into circulation. These five state quarters may be the hardest to find based on mintage data:

1. Oklahoma: 416.6 million minted
2. Maine: 448.8 million minted
3. Wisconsin: 453.2 million minted
4. Missouri: 453.2 million minted
5. Alabama: 457.4 million minted

Other state quarters with less than half a billion minted include Arkansas, Michigan, Illinois, Iowa, Florida, Minnesota, and New Mexico.

If you’re collecting state quarters and are still missing a few (maybe an Oklahoma or a Wisconsin), you’ll have to keep searching – the Mint is no longer producing the state quarters, meaning collectors have to turn to quarter machines, a coin dealer, or the change building up in their car’s cup holders.

Some state quarters – though few of the less-minted designs – could be worth even more than the 25 cents they were meant to be.

Those that are in mint condition and marked with a D or P (meaning they were produced in Denver or Philadelphia) could be worth as much as $3.50 if they have a certain state design, according to Coin Trackers. Ohio quarters marked with an S (produced in San Francisco) can carry the highest value at $15.

Of the less-minted states listed above, only a few are listed among the most valuable. A mint-condition Oklahoma or New Mexico quarter marked with an S could be worth up to $10. There are multiple other factors, like defects or whether it’s silver-proof, that can increase a state quarter’s value, including those that are in circulation.

If you’re looking to start a new quarter collection, the Mint is currently producing the American Women Quarters. Running through 2025, the four-year program highlights “the accomplishments and contributions made by women of the United States.” Last year, quarters honoring Maya Angelou, Dr. Sally Ride, Wilma Mankiller, Nina Otero-Warren, and Anna May Wong were released. This year, five more will be minted: Bessie Coleman, Edith Kanaka’ole, Eleanor Roosevelt, Jovita Idar, and Maria Tallchief.

The Mint spokesperson tells Nexstar the agency is authorized to redesign any of its legislated coins in honor of the U.S.’s 250th anniversary in 2026. Up to five different quarters with designs commemorating the semiquincentennial can be minted and released.

Between 2027 and 2030, the Mint is authorized to issue quarters “emblematic of sports played by American youth” and “a redesigned half-dollar each year with designs emblematic of a sport tailored to athletes with a range of disabilities, including physical impairment, vision impairment and intellectual impairment.”

The Secretary of the Treasury will be responsible for selecting the designs.