Col. James Pohl, the judge at Sinclair's court martial at Fort Bragg, North Carolina, ordered a reprimand and forfeiture of $5,000 in pay a month for four months, the Los Angeles Times reported. He also ordered Sinclair to repay $4,100 wrongly charged to a military credit card.
A military retirement board will decide on Sinclair's retirement rank, the judge said.
Pohl stopped the court-martial last week, finding that Sinclair had been wrongly blocked from a plea agreement. Sinclair's lawyers then negotiated a deal.
The defense team appeared happy with the sentence, the Times said. The lead lawyer, Richard Scheff said "Wow" and hugged a military member of the team, Maj. Sean Foster, while Sinclair hugged another lawyer, Ellen Brotman.
Critics said that top military officials, eager to show they were doing something about sexual misconduct by officers, accused Sinclair of sexual assault when he was guilty of a messy and adulterous consensual relationship that lasted for three years. Advocates for women in the military said that because of the command structure a relationship between a commander and subordinate can never be completely consensual.
Sinclair faced a possible life sentence if he was convicted on the most serious charges.