| Old | New | Comments |
| Personal exemptions ($4,050 in 2017) | Allowance amount instead of personal exemptions | There will be a new Federal withholding system in 2019 to reflect this change. This system has not yet been unveiled by the IRS but they are promising education and outreach in advance of the release. The old system of using personal exemptions is retained for 2018. |
| Standard deduction: Single $6,350 Married $12,700 | Standard deduction: Single $12,000 Married $24,000 | IRS will phase changes into the withholding system. 2018 tables have been issued and the IRS has released the 2018 Forms W-4 and an updated tax calculator. |
| Tax brackets 10%, 15%, 25%, 28%, 33%, 35%, 39.6% | Tax brackets 10%, 12%, 22%, 24%, 32%, 35%, 37% | |
| 25% supplemental rate up to $1M | 22% supplemental rate up to $1M | |
| 39.6% supplemental rate over $1M | 37% supplemental rate at least $1M | |
| Moving expenses tax-free. | Moving expense taxable. | Still can be taken by employers as a deduction |
| Bicycle commuting $20 per month tax-free | No tax-free bike benefit | Tax-free parking and auto commuting continue |
| Backup withholding rate of 25% | Backup withholding rate of 24% | Applies when payee doesn’t provide a TIN |