Where an individual engaged in medical practice or dental practice has, in any year, an amount to be received for social insurance medical care, if the amount to be received is 50,000,000 yen or less and the total of the amounts to be included in gross revenue pertaining to business income arising from the medical practice or dental practice engaged in by that individual is 70,000,000 yen or less, the amount to be included in necessary expenses as expenses pertaining to that social insurance medical care in calculating the amount of business income for that year is, notwithstanding the provisions of Article 37, paragraph (1) and Part II, Chapter II, Section 2, Subsection 4 of the Income Tax Act, the total of the amounts calculated by dividing the amount to be received into the amounts listed in the left-hand column of the following table and multiplying each of those amounts by the rate listed in the right-hand column of that table.
| The amount of 25,000,000 yen or less | 72 percent |
| The amount exceeding 25,000,000 yen but not exceeding 30,000,000 yen | 70 percent |
| The amount exceeding 30,000,000 yen but not exceeding 40,000,000 yen | 62 percent |
| The amount exceeding 40,000,000 yen but not exceeding 50,000,000 yen | 57 percent |
医業又は歯科医業を営む個人が、各年において社会保険診療につき支払を受けるべき金額を有する場合において、当該支払を受けるべき金額が五千万円以下であり、かつ、当該個人が営む医業又は歯科医業から生ずる事業所得に係る総収入金額に算入すべき金額の合計額が七千万円以下であるときは、その年分の事業所得の金額の計算上、当該社会保険診療に係る費用として必要経費に算入する金額は、所得税法第三十七条第一項及び第二編第二章第二節第四款の規定にかかわらず、当該支払を受けるべき金額を次の表の上欄に掲げる金額に区分してそれぞれの金額に同表の下欄に掲げる率を乗じて計算した金額の合計額とする。
| 二千五百万円以下の金額 | 百分の七十二 |
| 二千五百万円を超え三千万円以下の金額 | 百分の七十 |
| 三千万円を超え四千万円以下の金額 | 百分の六十二 |
| 四千万円を超え五千万円以下の金額 | 百分の五十七 |