The short answer is Yes, it may be a crime. The more nuanced answer is that it is a crime, tax evasion, to willfully attempt to evade the assessment or payment of a tax. I.R.C. Section 7201. Case law further holds that when you engage in a consistent pattern of overstating your deductions, it is tax evasion. The Eight Circuit explained that a “consistent pattern of overstating deductions” is tax evasion. Zacher v. U.S., 227 F.2d 219, 224 (8th Cir. 1955). Such a “consistent pattern” exists when, for example, the taxpayer “overstate[s] casualty losses, . . . the sales tax deduction claimed exceeded the amount of sales tax paid” and he “overstate[s] [his] repair costs.” Id.