As a single person for the 2017 tax year the standard deduction is $6350 and you get a personal exemption of $4050, so anything below $10400 pays no tax. The 10% bracket is on the first $9325 of taxable income, so you will pay 10% on income between $10400 and $19725. Similarly the 15% bracket goes to $37950, so you will pay 15% of any income between $19725 and $48350.

If you have access to a 403b and a 457 (and also to a deductible IRA as does anyone who can keep their Adjusted Gross Income below $62k), then you could make $48350 + $18000 403b + $18000 457 + 5500 IRA = $89850 and still be in the 15% bracket. Health insurance premiums paid through payroll deductions, contributions to an HSA and things like that could increase that limit further.

You say we, so if you're married the numbers change and you get a personal exemption for both yourself and your spouse (and any kids), but the basic idea stays the same.

Some people don't realize that once you move up a bracket you only pay the increased rate on the income in that bracket, not all of your taxable income. The fact that the increased tax rate is marginal means that you don't have worry too very much about the brackets. Yes, if you earn $1 over that $48350 you will pay $0.25, but it does nothing to change the taxes on the income below that threshold.