(1) The department may adopt rules under chapter 34.05 RCW for the administration and enforcement of this chapter. The rules, to the extent possible without being inconsistent with this chapter, must follow the internal revenue code and the regulations and rulings of the United States treasury department with respect to the federal income tax. The department may adopt as a part of these rules any portions of the internal revenue code and United States treasury department regulations and rulings, in whole or in part.(2) The department may adopt any rules under chapter 34.05 RCW it considers necessary for the administration of RCW 74.20A.273.[ 2026 c 238 s 710.]Notes:Findings—Intent—Effect of invalidation of 2026 c 238 s 201—Automatic expiration date and tax preference performance statement exemption—Necessity of act—Intent—Implementation by department of revenue—2026 c 238: See notes following RCW 82A.04.030.