①If a person who has contracted an illness or suffered an injury and who was an insured on the day on which the person underwent the first medical examination with a doctor or dentist in connection for that illness, injury, or for an additional illness caused by that illness or injury (those illnesses or injuries are hereinafter referred to as "injury or illness") (that day is hereinafter referred to as the "day of initial examination") has a disability of a degree of severity that is classified as any of the disability grades provided for in the following paragraph due to that injury or illness, as of the day after the day calculated as marking the passage of 1 year and 6 months' time since the day of initial examination (or, if the injury or illness has healed on any day within this period (including a day on which the symptoms thereof have stabilized and circumstances are such as that no curative effect is expected; the same applies hereinafter), as of that day; any day defined above is hereinafter referred to as the "day of disability assessment"), an employees' disability pension is paid to the person in accordance with the severity of the person's disability; provided, however, that this does not apply if, as of the day before the day of initial examination for the relevant injury or illness, the person had had an insured period under a National Pension that lasted up until the month two months before the month that includes the day of initial examination, and further, the total sum of the premium-paid period and the premium-exemption period does not comprise at least two-thirds of the relevant insured period.

②The disability grade is classified in order of severity from Grade 1 to 3, with Grade 1 being the severest, and the description of the disability for each grade is provided by Cabinet Order.