Under the plan, 11th and 12th grade classes in state schools, seventh to 12th grade classes in night government schools, and all 12 classes in private schools will reopen on August 22, the Education Ministry said.
Schools have been asked to observe advices by the health ministry to prevent the spread of coronavirus.
The move comes a week after universities fully reopened across the country.
Afghanistan has registered 37,162 cases of coronavirus and 1,328 deaths attributed to it.
A survey released by the Public Health Ministry recently, however, said that 10 million or nearly a third of the population have been infected with the virus.