Financial planner and Business Insider contributor Malik S. Lee says he's surprised when clients don't list their income as one of their most valuable assets.<br />Can you support yourself and your family without an income? If not, it's a key asset--and you should protect it.<br />Group long-term disability policies from employers typically cover 60% of your income. But according to Business Insider, that income is taxable and doesn't include bonuses or commissions.<br />If you're self-employed, an independent contractor, a sole proprietor, or a gig economy worker, disability insurance is even more critical.<br />Finally, if one part of your body is critical to your work, such as a surgeon's hands or a singer's voice, disability insurance should be high on your priority list.