Caroyl incurred $8,700 of medical expenses in November 2013. On December 5, the clinic where she was treated mailed her the insurance claim form it had prepared for her with a suggestion that she sign and return the form immediately to receive her reimbursement from the insurance company by December 31. What tax issues should Caroyl consider in deciding whether to sign and return the form in December 2013 or January 2014?