Employee contributes up to 100 % of eligible compensation through salary deferral, not to exceed $ 12,500 for 2018 (fidelity.com)
Anyone under age 70 1/2 with eligible compensation, such as wages, can contribute to a traditional IRA, but there are income limits if you are covered under an employer retirement plan and you want to take a tax deduction on your contributions. (nbr.com)
In 2017, employers can contribute between 0 % - 25 % of eligible compensation up to $ 54,000, whichever is lesser. (firstcitizens.com)