The IRS guidelines for IRA contribution limits are reviewed each year. There were no changes between 2017 and 2018, for example, so the maximum contribution is the lesser of: $5,500 for investors under 50, $6,500 for those 50 or older; or your taxable compensation for the year.
There are additional contribution limits, based on your income and other factors. More comprehensive details of the limits on contributions can be found: here
A traditional IRA is pretty straightforward. Anyone (or their spouse) who meets the below requirements can invest in one:
Must be a U.S. resident with a permanent U.S. address
Must have a social security number (SSN)
Must be over the age of 18 and under the age of 70 ½
Must receive taxable income
If you’re single and working, then you can invest in a traditional IRA. If you’re a married breadwinner, you can invest in a traditional IRA. If you’re a stay-at-home spouse and your spouse is earning taxable income, then you can invest in a traditional IRA. You can do it if you’re married and both working. All as long as you’re under the age of 70 ½. You can invest in a traditional IRA whether or not you have an employer-sponsored retirement account. There’s no minimum to how long you have to be at one company. There’s no need to even be at just one company. You can change jobs, start a business, work as a freelancer, or all of the above.
As long as you’re under 70 ½ and earning taxable income, you can invest in a traditional IRA. It’s that simple.
Please note, the above is in no way intended to provide tax advice for your specific situation. Aspiration cannot provide tax advice, and recommends that you consider the tax consequences prior to making an investment decision.