1. In light of the provisions and purport of Article 49 subparag. 2, Articles 54(1), 67(1) and (5) of the former National Pension Act (amended by Act No. 11143, Dec. 31, 201; hereinafter the same) and Article 46 and attached Table 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), disability pension under the National Pension Act is a continuous payment of disability to a person with a physical or mental disability even after he/she was completely cured due to a disease or injury caused during the subscription to the National Pension Service, and a subscriber acquires a right to claim the payment of disability pension at the time of the completion of treatment. Therefore, disability pension payment should be determined based on the principle of disability ratings at the time of the completion of treatment, i.e., disability pension payment at the time of the completion of disability pension, which should be modified by the existing law.

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 (amended by Presidential Decree No. 2006-47, Jun. 14, 2006; hereinafter “existing public notification”) stipulating that the degree of disability should be determined based on the national pension disability examination rules (amended by Presidential Decree No. 2006-47, Jun. 14, 2006; hereinafter “existing public notification”), if a person who is not entitled to a disability pension becomes entitled to a disability pension before he/she turns 60 years of age due to aggravation of the disease or injury, he/she shall be recognized that the new public announcement was made on the date when he/she requests for the determination of the degree of disability, and that the new public announcement was made on the date when he/she became subject to a disability pension after being 10 years of age or less after being 10 months of the first public announcement on the extension of the disability grade 20.

B. Meanwhile, according to the reasoning of the lower judgment, when the Plaintiff applied for a disability pension on November 18, 2002 with the chronic renal failure as a cause of disability, the Defendant rendered a decision that the Plaintiff fell under the disability grade 2 on December 30, 2002, and subsequently maintained the determination of disability grade 2 by deciding that the Plaintiff’s disability remains the same as that of the Plaintiff’s disability through ex officio reexamination by June 5, 2008, and the Plaintiff continued to conduct an ex officio reexamination on the Plaintiff’s disability grade 1, 209; the Defendant, who received a kidne surgery on August 10, 2009, conducted an ex officio reexamination on the Plaintiff’s disability grade; by applying the amended notification on August 16, 2010, was a person who received a kidne surgery by the Plaintiff, who received a kidne surgery and did not reach the degree 3, thereby making a decision to change the disability grade 2 through Grade 4 (hereinafter “instant disposition”).

C. Examining these factual background and the background leading up to the amendment of the National Pension Review 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, “the completion date, etc.,” which is the base date for determination of the degree of disability. Since “the completion date, etc.,” of a person who received a expanded transplant is stipulated in the public notice on the date when six months elapse from the date of a kidne surgery, the Plaintiff’s medical treatment date should be deemed February 11, 2010. Accordingly, the previous public notice, which was enforced on February 11, 201

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 So-young (Presiding Justice)