Broadband for All Act of 2018 This bill amends the Internal Revenue Code to allow a refundable tax credit of up to $10,000 per year for 75% of a taxpayer's payments for broadband infrastructure in certain areas (limited broadband districts) that are not served by a provider of qualified broadband service (other than providers using satellite technology). "Qualified broadband service" is Internet access service at download speeds of at least 25 megabits per second and upload speeds of at least 3 megabits per second.