The former government of Nikita Khrushchev was dissolved following his removal from the post of the Chairman of the Council of Ministers. Alexei Kosygin was elected Premier by the Politburo and the Central Committee following the removal of Khrushchev. His first government would last for two years, until the 1966 Soviet election held in June. Kosygin's first government saw the re-creation of many ministries that were removed under Khrushchev's previous government.
References
Kosygin's First Government Wikipedia(Text) CC BY-SA