The Internal Revenue Service has decided to exempt medical residents from Medicare and Social Security taxes for tax years ending before April 1, 2005, when it established a new rule categorically excluding them from the "student" exemption. The deadline for filing claims has expired, but employers and individual medical residents who filed a timely claim are eligible to receive refunds. The agency plans to provide eligible hospitals, universities and medical residents with more information within 90 days, including how to receive the funds. Employers and residents with pending lawsuits should contact the Department of Justice attorney assigned to their case. Lawrence Hughes, AHA assistant general counsel, said the IRS decision does not negate the need for the U.S. Supreme Court to review the 2005 rule, as requested in a pending case for which AHA last month filed an amicus brief. The rule costs teaching hospitals and medical schools an estimated $700 million annually.  For more on the IRS decision affecting claims before April 2005, visit www.irs.gov/charities.