What is a SCH 3900?

[DoninGA]

SCH on the Form 1040 line for wages indicates that there is taxable scholarship amount included.  The number after the SCH code is the amount of the taxable scholarship included.  In this instance the taxable scholarship included would be $3,900

See this TurboTax support FAQ for taxable scholarships - https://ttlc.intuit.com/community/college-and-education/help/why-is-my-scholarship-taxable/01/26267