Beuran Hendricks, Anrich Nortje, Dwaine Pretorius and Rassie van der Dussen have all been handed full national contracts by Cricket South Africa.
The CSA contracted 16 men's players in an announcement on Monday, ahead of a 12-month period that includes the T20 World Cup in Australia.
Paceman Hendricks, who made his Test debut against England in January, has been awarded his first national contract, while fellow bowler Nortje earned a contract upgrade over the past season.
Also upgraded as a result of their appearances and performances for the Proteas are batsman Van Der Dussen and all-rounder Pretorius.
A decision has been taken to leave the 17th men's contract spot open so other players have the opportunity to qualify for it, CSA Acting Chief Executive Dr. Jacques Faul said.
Faf du Plessis is one of the 16 players contracted after he gave up the South Africa captaincy to Quinton de Kock across all formats in an announcement last month.
"We have contracted 16 men's players and 14 women's players which we feel is the appropriate number to maintain our national squads across the various formats," said Faul.
"This enables us to contract both our Test players as well as those who are limited-overs specialists."
CSA contracted men’s players: Temba Bavuma, Quinton de Kock, Faf du Plessis, Dean Elgar, Beuran Hendricks, Reeza Hendricks, Keshav Maharaj, Aiden Markram, David Miller, Lungi Ngidi, Anrich Nortje, Andile Phehlukwayo, Dwaine Pretorius, Kagiso Rabada, Tabraiz Shamsi, Rassie van der Dussen.