A brigade commander and military intelligence chiefs were among those to lose their jobs, the defence ministry said in a statement, added that the officers could also face prosecution.
"The decision was taken by high council of defence after the army chief of staff briefed the council about the incident," the ministry said.
Hundreds of militants stormed the outpost in the eastern province of Kunar on Sunday, triggering a four-hour battle that left 21 soldiers dead and five others missing.
Afghanistan's army and police have taken over much of the responsibility for tackling the insurgency that erupted after the Taliban were toppled from power in 2001. But doubts remain about their ability to secure the country.
After the attack, President Hamid Karzai blamed Islamabad for failing to crack down on Taliban safe havens in Pakistan, where militant leaders seek sanctuary from Afghan and US military operations.
Afghanistan and Pakistan regularly accuse each other of supporting militant attacks in the other's country. Karzai's comments came days after Islamabad said 23 of its kidnapped paramilitary soldiers had been killed on Afghan soil.