Protecting Family and Small Business Tax Cuts Act of 2018 This bill amends the Internal Revenue Code to make permanent several tax provisions that were enacted in 2017 and are scheduled to expire at the end of 2025. The bill makes permanent provisions that: reduce individual tax rates, modify the taxation of the unearned income of children, allow a deduction for qualified business income of pass-through entities, increase the standard deduction, increase and modify the child tax credit, increase the limitation for certain charitable contributions, allow additional contributions to ABLE accounts (tax-favored accounts designed to enable individuals with disabilities to save for and pay for disability-related expenses), allow certain members of the Armed Forces in the Sinai Peninsula of Egypt to receive combat zone tax benefits, exclude from gross income discharges of student loan debt due to the death or disability of the student, repeal the deduction for personal exemptions, limit individual deductions for state and local taxes, limit the mortgage interest deduction, double the estate and gift tax exemption amount, increase the alternative minimum tax exemption amount for individuals, and repeal or limit several other deductions and exclusions. The bill also: extends through 2020 the reduction in the adjusted gross income threshold for the medical expense deduction, modifies the capital gains tax brackets, and modifies tax filing requirements for married taxpayers.