In 2000, DePuy, Inc., filed a New Mexico corporate income tax return for 1999 on a unitary domestic combined basis, as it had in previous years. The return requested a refund of nearly $80,000. In 1998, Johnson and Johnson, Inc., acquired DePuy. After Johnson and Johnson told DePuy that it should file on a separate entity basis, DePuy filed an amended return for 1999 on that basis. In 2002, DePuy sent a letter formally requesting permission to change its filing status from unitary domestic combined to separate entity, beginning with the 1999 tax year. In February, 2004, DePuy received a letter from the Department granting permission to file as a separate corporate entity, beginning with the 1999 tax year. DePuy resubmitted its amended 1999 corporate income tax return, showing a refund due of $79,241. The Department denied the refund because DePuy’s amended returns were resubmitted after expiration of the three-year limitations period set by Section 7-9-26 NMSA 1978. DePuy protested the refund denial. The hearing officer denied the protest, finding that the Department’s February, 2004, letter giving DePuy retroactive permission to change to separate entity filing was effective for all years still within the statutory limitations period, but the amended 1999 returns DePuy filed in 2004 were beyond that period.