第1号被保険者の年齢階級別分布や所得分布の格差によって、第1号被保険者の介護保険料は地域間で格差が生じる。そのため国庫負担のうちの5%は、市町村の介護保険財政の格差を調整するために交付されている。それが公的介護保険における調整交付金である。本稿は各市町村に交付される普通調整交付金を決める一要素である後期高齢者加入割合補正係数に焦点をあて、調整交付金について再検討を行った。つまり、後期高齢者加入割合補正係数の精緻化が、調整交付金割合に及ぼす影響について定量的に検討した。分析の結果、本稿で提示した算定式のほうが、現行の算定式よりも、各市町村における第1号被保険者の年齢階級別構成割合に応じて、市町村間の介護保険財政を調整できることを確認できた。

There are regional imbalances in long-term care insurance premiums for primary insured persons because of the difference of the distribution by age group of primary insured persons, and the distribution of income of primary insured persons. Therefore 5% of the public expenditure from the national government shall be appropriated for the adjustment of gaps of municipalities' finance of long-term care insurance. That expenditure is Adjusting Subsidies. This paper reexamines the effect of Adjusting Subsidies. This study focuses on the mechanism which the regular adjusting subsidies for each municipality is calculated through, and analyzes the participation ratio correction coefficient for the latter-stage elderly to adjust the gaps of the proportion of later elderly persons' participation. The results suggest that the proposed mechanism is adjusted the finances of long-term care insurance in accordance with the distribution by age group of primary insured persons better than the present mechanism.