2005 Federal Sentencing Guidelines
Chapter 2 - PART T - OFFENSES INVOLVING
TAXATION
§2T1.6. Failing to Collect
or Truthfully Account for and Pay Over Tax 
(a) Base Offense Level: Level from §2T4.1 (Tax Table) corresponding to
  the tax not collected or accounted for and paid over.
(b) Cross Reference
  (1) Where the offense involved embezzlement by withholding tax from an employee’s
    earnings and willfully failing to account to the employee for it, apply §2B1.1
    (Theft, Property Destruction, and Fraud) if the resulting offense level is
    greater than that determined above.
Commentary
Statutory Provision: 26 U.S.C. § 7202. 
Application Note:
1. In the event that the employer not only failed to account to the Internal
  Revenue Service and pay over the tax, but also collected the tax from employees
  and did not account to them for it, it is both tax evasion and a form of embezzlement.
  Subsection (b)(1) addresses such cases.
Background: The offense is
  a felony that is infrequently prosecuted. The failure to collect or truthfully
  account for the tax must be willful, as must the failure to pay. Where no effort
  is made to defraud the employee, the offense is a form of tax evasion, and
  is treated as such in the guidelines. 
Historical Note: Effective
  November 1, 1987. Amended effective November 1, 1989 (see Appendix
  C, amendment 232); November 1, 1991 (see Appendix
  C, amendment 409); November 1, 2001 (see Appendix
  C, amendment 617).