Gay couples will be allowed to marry in Maryland starting Jan. 1, but as things stand now, they won’t be allowed to file joint tax returns. Comptroller Peter Franchot said Wednesday that he is committed to changing that before income taxes are due for 2013. At issue is Maryland’s status as a “conforming state,” meaning its tax laws are parallel to those of the federal government unless otherwise spelled out in state law. Federal law doesn’t recognize same-sex marriages, and Maryland uses income reported to the Internal Revenue Service as a starting point in computing state tax obligations. Franchot said he will either pursue legislation in the upcoming session of the General Assembly to change the policy or find a way to accomplish the same thing for gay couples through regulations. “My senior staff and I will work with legislative leaders over the next few weeks to determine the most appropriate course of action,” Franchot said in a statement, in which he noted that he was a supporter of the state’s same-sex marriage law.