AABC bat rules (2027)

AABC bat rules by division, including the older Connie Mack and Stan Musial age groups.

Division	Season	Stamp	Barrel	Max length	Drop limit
Clemente (8U) through Nolan Ryan (13U) Ages 7–13	Current	USABat or Wood	2 5/8"	—	—
Sandy Koufax (14U) Age 14	Current	BBCOR or Wood	2 5/8"	—	-3 or heavier
Griffey (15U), Mantle (16U), Mattingly (17U), Connie Mack (18U) & Stan Musial Ages 15+	Current	Wood	—	42"	—

Notes by division

Clemente (8U) through Nolan Ryan (13U): Every non-wood bat must carry the USA Baseball mark, so USSSA-only bats are NOT legal at AABC tournaments.
Griffey (15U), Mantle (16U), Mattingly (17U), Connie Mack (18U) & Stan Musial: Wood only. The only composites allowed are the Baum Bat and the Zinger composite. The handbook lists a 2.61" max diameter.

Stamps used in AABC

USA Baseball (USABat) mark: USA Baseball's youth standard, which makes bats perform close to wood. Barrel up to 2 5/8", no drop limit, and no new USABat is made longer than 32". Required in Little League, Cal Ripken, PONY, Diamond Youth (Dixie), AABC and most rec leagues. Official list.
one-piece solid wood: One-piece solid wood is legal almost everywhere without a stamp. Multi-piece, laminated, bamboo and composite-wood bats usually do need a certification mark.
BBCOR .50 mark: The high school and college standard: -3 drop, barrel up to 2 5/8", 36" max. BBCOR bats made before USA BBCOR stay legal in high school indefinitely, but the NCAA requires the new USA BBCOR mark from Jan 1, 2029. Official list.

Sources

https://aabc.us/wp-content/uploads/AABC_Handbook26.pdf (checked Oct 23, 2026)

This page summarizes published rules. Your league or tournament can add its own, and its ruling is final. Confirm your bat isn't on a decertified or non-approved list before you buy. Questions about a specific model? Check the official list linked above. More bat questions.

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