Cals semi-retired from active politics at just 52 and became active in the private and public sectors as a corporate and non-profit director, and served as a diplomat and lobbyist for several economic delegations and presided over several state commissions and councils for the government. Cals was known for his abilities as a efficient manager and his work ethics. During his premiership, his cabinet were responsible for major social reforms to social security, closing the mines in Limburg and stimulating Urban development in the Randstad. Cals was granted the honorary title of Minister of State on 5 December 1966 and continued to comment on political affairs as a statesman until he was diagnosed with a terminal brain tumor and died in December 1971 at the age of just 57. He holds the distinction of as the fourth longest-serving cabinet member since 1850 with 14 years and 353 days and his premiership is consistently considered both by scholars and the public to have been average.