Mr Sanders’ annual income, which is shared with his wife, is less than his multimillionaire rival made for three recent speeches delivered to Goldman Sachs employees.
The banking giant paid Ms Clinton $675,000 (£475,000) for the appearances. She and her husband have an estimated net worth of $110m (£77m), far surpassing the Sanders, who are worth around $300,000 (£210,000).
Income inequality has been a key plank of Mr Sanders’ campaign, leading Ms Clinton to challenge him to publish his earnings. On Thursday, she said: “I’ve released 30 years of tax returns, and I think every candidate, including Senator Sanders and Donald Trump, should do the same.”