The limits shown on IRS.GOV for 2018 are as follows:

"The limitation for defined contribution plans under Section 415(c)(1)(A) is increased in 2018 from $54,000 to $55,000."

"The contribution limit for employees who participate in 401(k), 403(b), most 457 plans, and the federal government’s Thrift Savings Plan is increased from $18,000 to $18,500."

"The catch-up contribution limit for employees aged 50 and over who participate in 401(k), 403(b), most 457 plans and the federal government’s Thrift Savings Plan remains unchanged at $6,000."

Remember that the limit of $55,000 (assuming you are under 50) applies to contribution from all sources, so if you contribute $18,500 then the company can only contribute $36,500.

Now that would mean you would still have to make over $300k, and I think the IRS limits the income that can be used to $275k, so that shouldn't be a factor.