Agricultural G-18 Specification

Marketing June 4, 2020

Service

Quality Assessment Division 

1400 Independence Avenue SW, Stop 0258 

Washington, DC 20250 Page 1 of 2 

USDA is an equal opportunity provider, employer, and lender.

STX Premium Angus Beef Program

G-18 Specification

1 REQUIREMENTS

Beef carcasses certified under this specification shall meet the following requirements: 

a. Phenotypic or genotypic requirements of the American Angus Association’s (AAA) Live

Animal Specification;

b. Classed as Steer or Heifer carcasses only1;

1

2

3

4

;

c. U.S. Prime only and have a minimum marbling score of Slightly Abundant 0 ;

d. Less than 30 months of age with lean color, texture, and firmness, meeting the requirements for

A maturity in the U.S. grade it qualifies for1;

e. Medium or fine marbling texture1, ;

f. Ribeye Area (REA) of 10.0 to 16.0 square inches ;

g. Hot Carcass Weight (HCW) of 1,050 pounds or less

h. Fat Thickness (FT) less than 1.0 inch5

6

7

;

i. Minimum muscling requirement ;

j. No hump exceeding 2 inches in height ;

k. Practically free (not detracting from visual quality) of capillary rupture in the ribeye muscle;

and

l. Free of “dark cutting” characteristics.

2 CERTIFICATION

Carcasses to be examined for compliance with this specification shall be clearly identified and 

presented to an AMS grader for certification. Certification procedures for identification, the removal 

of preliminary identification marks (or other methods of control) from non-qualifying carcasses, and 

control of certified carcasses shall be in accordance with established Quality Assessment Division 

(QAD) procedures.

1 Determined in accordance with the “Official United States Standards for Grades of Carcass Beef.” 2 Evaluated using the USDA-AMS-LS-SB-02 Marbling Texture card (included in the Official USDA Marbling Photographs.) 3

 REA is inclusive of the lower and upper limits and allows for one side to meet the standard to consider both eligible for certification. 4 Establishes a maximum allowable HCW of 1,050 lbs. as determined and applied to the carcass at the hot scale. *(If Kidney, Pelvic and 

Heart Fat is fully or partially removed and not accounted for in the final HCW, then HCW must be less than 1,025 lbs.)

5 FT is to be determined at the 12th rib and represent solely an evaluation of subcutaneous fat over the ribeye at a point 3⁄4 the lateral 

length of the eye muscle from the backbone. If the actual FT over the ribeye has been altered due to a hide pull, gouge, trim, or other 

irregularity, a predicted line shall be determined along the curvature of the ribeye to establish an accurate prediction of unaltered fat 

thickness at the 12th rib surface. FT may be determined on either side of the carcass with at least one side meeting the standard to 

consider both eligible for certification. 6 Muscle thickness is evaluated by averaging the thickness of the various parts, considering not only the proportion of each part of the 

carcass but also the general value of each part. Superior muscle thickness implies a high proportion of meat to bone and a high 

proportion of the weight of the carcass in the more valuable parts. 7 Measured from a line formed by the extension of the top line (including the fat) and measuring the lean muscle (excluding the fat) 

perpendicular to that line in the center of the hump.
Agricultural G-18 Specification

Marketing June 4, 2020

Service

Quality Assessment Division 

1400 Independence Avenue SW, Stop 0258 

Washington, DC 20250 Page 2 of 2 

USDA is an equal opportunity provider, employer, and lender.

3 LABELING

Labeling of products derived from certified carcasses must follow Food Safety and Inspection Service 

regulations and policy guidelines and QAD procedures.

4 FEES

The costs of all grading and certification services performed by an AMS grader involving 

examinations, supervision, official documentation, and related services shall be borne by the person, 

group, or plant requesting the service. 

___________________________________

Chad Nelson, National Meat Supervisor 

Standards and Specifications Division

Livestock & Poultry Program