1. In light of the provisions and purport of Articles 49 subparag. 2, 54(1), and 67(1) and (5) of the former National Pension Act (amended by Act No. 11143, Dec. 8, 2011; hereinafter the same shall apply), Article 46 and [Attachment 2] of the former Enforcement Decree of the National Pension Act (amended by Presidential Decree No. 23359, Dec. 8, 201; hereinafter the same shall apply), a disability pension under the National Pension Act is paid to a person with a physical or mental disability who has been completely cured due to a disease or injury incurred during the subscription to the National Pension, and a subscriber acquires a right to claim payment of a disability pension. Accordingly, the disability pension should be determined at the time of the completion of treatment, i.e., the payment of a disability pension, in principle, at the time of the completion of disability pension benefits, by changing the amount of disability grade as at the time of the completion of treatment.

2. A. According to Article 67(1) and (2) of the former National Pension Act, and Article 46(4) of the former Enforcement Decree of the National Pension Act, the National Pension Examination Regulations (amended by the Ministry of Health and Welfare No. 2006-47 of Jun. 14, 2006; hereinafter referred to as "existing Public Notice") stipulating the degree of disability, etc. to be determined based on the request of a person who is not entitled to a disability pension before reaching the age of 60 due to aggravation of the disease or injury, if the person who is not entitled to a disability pension becomes entitled to a disability pension before reaching the age of 60 (hereinafter referred to as "the above, 1, 2, 3, 206-47 of the Enforcement Decree of the National Pension Act"), it is recognized that the new disability grade has been modified from 10 months to 20 days after the date of extension of transplant, and the new disability grade has been recognized as 10-19 days after the new public announcement.

B. Meanwhile, according to the reasoning of the judgment below, when the plaintiff applied for a disability pension on November 18, 2002 with the chronic renal failure as a cause of disability, the defendant made a decision that the plaintiff fell under the disability grade 2, 302. The plaintiff made a decision that the plaintiff sustained the same disability as that of the plaintiff through an ex officio review until June 5, 2008, and maintained the decision of disability grade 2. The plaintiff continued to conduct a further re-examination on August 10, 2009. After the plaintiff conducted an ex officio re-examination on the plaintiff's disability grade, the defendant, who received a further re-examination on August 16, 2010, was a person who received a further re-examination by applying the revised notification on August 16, 2010, and was made a decision that changed the disability grade 2 through grade 4 (hereinafter "the disposition in this case").

C. Examining these facts and the background leading up to the amendment of the disability pension examination regulations, in light of the aforementioned legal principles, disability grade determination for the payment of disability pension amount should be based on the laws and regulations at the time of occurrence of the ground for disability grade determination, namely, on the date of completion of disability grade determination, which is the base date for determination of the degree of disability. Since 'the completion date, etc. of a transplant recipient' is stipulated in the public notice on the date when 6 months elapse from the date of extension surgery, the Plaintiff’s completion date should be deemed February 11, 2010. Accordingly, the Plaintiff’s modification of disability grade should be applied to the Plaintiff’s modification of disability grade determination.

D. Nevertheless, the lower court determined that the instant disposition that applied the revised notice on the grounds stated in its reasoning, such as that an administrative disposition should, in principle, be conducted based on the law that was enforced at the time of the disposition, was lawful. In so doing, the lower court erred by misapprehending the legal doctrine on the determination of applicable statutes when determining disability grades under the National Pension Act

3. Therefore, without examining the remaining grounds of appeal, we reverse the judgment of the court below and remand the case to the court below for a new trial and determination. It is so decided as per Disposition by the assent of all participating Justices on the bench.

Justices Kim Yong-deok

The Chief Justice Park Jae-young