Our usual income is below $20,000 annually, but we sold our home in 2017. Is the $300,000 gain taxable?

It depends on whether you qualify for the home sale exclusion. This exclusion lets you omit from gross income up to $250,000 of gain ($500,000 on a joint return), but only if you meet certain conditions:

• You must have owned and use the home as your principal residence for a period aggregating two of the five years preceding the date of sale. You are permitted to meet these two separate tests (ownership and use) using different two-year periods. The five-year period can be suspended for certain government employees (e.g., those in uniform, foreign service, or intelligence).
• You didn’t claim a home sale exclusion for a sale that was within two years preceding the date of your current sale.