The Brewers Association, a trade group that represents the nation’s craft brewers, reported Tuesday that volume increased 6% to 24.6 million barrels in 2016, a slowdown from the double-digit increases the industry had been posting in recent years. Volume had increased 13% in 2015 and 18% in the preceding two years, but the BA admitted those heady days were likely in the past.

“The era of 18% growth rate is probably over,” Bart Watson, chief economist of the Brewers Association, said during a media presentation. “The industry is a maturing industry. Having those growth rates in an industry of this size is impossible going forward.”

Craft brewers have become the darlings of America’s $108 billion beer market, having sold consumers on the premise that fuller-flavored beers created by small, regional brewers were more compelling than those from industry heavyweights. Beer lovers bought in and are willing to pay more for a craft brew than a Bud or Miller. Major brewers took notice, and all four of the biggest players that operate in the U.S.— Anheuser-Busch InBev, Molson Coors, Heineken, and Constellation Brands—have been on a craft-brew buying-spree.

“As the overall beer market remains static and the large global brewers lose volume, their strategy has been to focus on acquiring craft brewers,” Watson said. But when those deals are inked, the increased volume from labels like Ballast Point and others are no longer considered “craft,” thus hurting the sub-segment’s industry growth. Four craft brewers were removed from the BA’s Top 50 Craft Brewing list because of recent deal making.

Increased competition is also to blame. More than 5,000 brewers are now competing for retail shelf space and bar taps. Meanwhile, regional powerhouses like Sam Adams are being squeezed by Big Brewers like AB InBev and hyper-regional upstarts that can sell the “small” and “local” story better than its 33-year-old parent company, Boston Beer. “I’ve heard speculation from a couple of retailers that perhaps the fact that there were too many choices has in fact turned customers away from craft,” chairman and founder Jim Koch said last month.

The pressure is also resulting in some increased closures. 97 craft brewers shut down last year, up from 78 in 2015 and 75 the year before.

Stagnant growth is so problematic that craft brewers are almost certain to fall short of the BA’s lofty goal of snagging 20% volume market share by 2020. Market share stood at 12.3% in 2016, up sharply from 5.7% in 2011, but it barely budged from 2015’s 12.2%.

“I think it is a long shot at this point,” said Watson. “It would be very hard for us to reach that goal at this point.” He described it as an “aspirational” target set by the trade organization to get craft brewers to think bigger picture about sourcing key ingredients like hops and other raw materials.

Within the craft beer category, much of the growth is actually being propelled by smaller, local peers rather than the bigger craft players that have grown to become national names (i.e. Sam Adams, Sierra Nevada, New Belgium). When Watson was asked if any of those smaller upstarts could one day hope to break out as a bigger player like Sierra Nevada had, he didn’t seem that optimistic about the possibility.

“To move from a regional to a super-regional would be very difficult,” Watson said. “It is much more of a long shot than 10 or two years ago, though I won’t rule it out completely.”

Fortune has called out one way for craft brewers to compete: mergers among peers to grow distribution and sourcing materials. Pennsylvania’s Victory Brewing and New York’s Southern Tier Brewing formed an alliance last year to create a new company called Artisanal Brewing Ventures. Duvel Moortgat and Oskar Blues Brewing have also been acquisitive. Industry watchers see that trend of regional M&A continuing, and it could be the best way for brewers to create scale while holding on to their independence.