9 - The Act and Regulations

The term “assessment for determining eligibility and vocational rehabilitation needs” means...to the extent additional data is necessary to make a determination of the employment outcomes, and the nature and scope of vocational rehabilitation services, to be included in the individualized plan for employment of an eligible individual, a comprehensive assessment to determine the unique strengths, resources, priorities, concerns, abilities, capabilities, interests, and informed choice, including the need for supported employment... 

(See 29 USC § 705(a)(2) - Definitions, Assessment for determining eligibility and vocational rehabilitation needs.)

The designated State unit must conduct an assessment for determining vocational rehabilitation needs, if appropriate, for each eligible individual or, if the State is operating under an order of selection, for each eligible individual to whom the State is able to provide services. The purpose of this assessment is to determine the employment outcome, and the nature and scope of vocational rehabilitation services to be included in the individualized plan for employment. 

(See 34 CFR 361.45(b) - Development of the individualized plan for employment, Purpose.)