Small Business Tax Credit Accessibility Act This bill amends the Internal Revenue Code, with respect to the small employer health care insurance tax credit, to: (1) revise the definition of "eligible small employer" to mean an employer with not more than 50 (currently, 25) full-time employees; (2) modify the phaseout formula for such credit to base such phaseout on number of employees and average annual wages; (3) extend from two to three consecutive taxable years the period during which an employer may claim such credit; and (4) eliminate the requirement that employers contribute the same percentage of cost of each employee's health insurance and the cap limiting eligible employer contributions to average premiums paid to a state health insurance exchange.