Your distribution is partly nontaxable, but mostly taxable, calculated on Form 8606 Part I. Given that your RMD was $7,000, I'm guessing that the $18,000 of basis in nondeductible traditional IRA contributions represented about 10% of your balance in traditional IRAs. If so, 10% ($700) of the distribution will be nontaxable and 90% ($6,300) of the distribution will be taxable. This will also result in your basis carried forward to 2018 being reduced to $17,300.
