[2] Rybeck received a Licentiate of Medical Science (Medicine licentiatexamen) degree in Stockholm in 1960 and then worked as an assistant physician (underläkare) at Norrbackainstitutet in Stockholm from 1960 to 1962 and then at the orthopedic clinic at Uppsala University Hospital from 1962 to 1964.
Rybeck then served as chief defence physician (försvarsöverläkare) from 1975 to 1976, as an Army Staff doctor from 1976 to 1979 as well as acting Surgeon-General of the Swedish Armed Forces from 1979 to 1980.
[2] From 1994 to 1995, Rybeck was the director general of the National Board for Strategic Defence Research (NSF).
[3] Member of the Central Committee of the Swedish Society of Military Medical Officers (Svenska Militärläkareföreningen) from 1969 to 1979, secretary of the Disaster Medicine Organizing Committee of the Defence Medical Research Delegation from 1971 to 1974, medical delegate in Pakistan for the Red Cross in 1972, member of the delegation for the development of international law rules on humanity in war from 1974, medical expert at the Ministry for Foreign Affairs at the diplomatic conference on the laws of war in Geneva from 1973 to 1976, chairman of the UN expert meeting in Geneva on disarmament negotiations on bacteriological weapons in 1987, Nämnden för strategisk försvarsforskning ("Board for Strategic Defense Research") from 1994 to 1995.
The funeral service was held on 23 January 2020 in Grödinge Church in Botkyrka Municipality.