Two policies, two payees, and an owner-operator usually needs both. Personal disability insurance pays the disabled individual a stated monthly benefit to replace their income. Business overhead expense insurance pays the business, and only for expenses it has actually incurred. A solo dentist who breaks a wrist has two simultaneous problems: her household still has a mortgage, and her practice still has rent, a hygienist's wages, equipment leases and a phone line. The two products address one problem each, and neither substitutes for the other.
It reimburses rather than indemnifies, and that changes the shape of the benefit. New York's product outline describes the standard structure as one in which "covered overhead expenses actually incurred for each month are reimbursed for each month of total disability," subject to "a maximum monthly benefit each month and to an overall reimbursement level determined by a maximum benefit period expressed in time or a cumulative maximum monthly overhead expense benefit expressed in dollar terms." So a business whose expenses run below the monthly maximum receives less than the maximum, and many policies allow the unused amount to carry forward within the overall cap. That is the opposite of a personal disability policy, which pays its stated benefit whether the insured's actual expenses are high or low.
What counts as a covered expense, and the exclusion at the center of it. The categories are the fixed costs of keeping the doors open: rent or mortgage interest on business premises, utilities, telephone and internet, employee wages and payroll taxes, property and liability insurance premiums, equipment leases, professional dues, accounting and legal fees, and depreciation. The IRS revenue ruling that established the tax treatment of these policies describes the same list and states the exclusion in the same breath: covered expenses "shall include rent, electricity, heat, water, laundry, depreciation, employees' salaries and such other fixed expenses as are normal and customary in the conduct and operation of the insured's office but shall not include salary, fees, drawing account or any other remuneration for the insured or any other member of the insured's profession hired by or working with the insured." The owner's replacement is generally not covered either, which is a point owners are surprised by: hiring a locum to keep the practice running is often the first thing they want to do and often the thing the policy will not pay for. Whether a policy covers a substitute professional is a term to check before buying.
The benefit period is short on purpose. New York's filing standards give a sense of the range it will approve: an elimination or waiting period "of reasonable duration chosen by an insured (generally no longer than 6 months)" before benefits begin, and a maximum benefit period of which the Department says "generally, a maximum benefit period of at least one year would be considered reasonable." Those are that Department's own standards for approving a form rather than a description of the national market, but they reflect what the product is for. It buys time to recover, to bring in a partner, or to wind down or sell in an orderly way. It is not a substitute for long-term disability coverage on the owner personally, which can run to age 65 or beyond.
The tax treatment is the mirror image of personal disability insurance, and the IRS puts both rules on facing pages. Publication 334, the Tax Guide for Small Business, lists among deductible business insurance premiums "overhead insurance that pays for business overhead expenses you have during long periods of disability caused by your injury or sickness." Its list of non-deductible premiums includes, at item 2, "loss of earnings. You can't deduct premiums for a policy that pays for your lost earnings due to sickness or disability. However, see item 8 in the previous list." The cross-reference is the IRS pointing from one product to the other: personal disability premiums are not deductible, overhead expense premiums are.
The consequence on the benefit side follows from the deduction. Revenue Ruling 55-264 holds that proceeds from an overhead expense disability policy are includible in gross income under section 61 and that the premiums are deductible under section 162, reasoning that such policies "are issued strictly for business purposes and in no way compensate the insured for injuries or sickness." So the benefits are taxable to the business. In practice the effect is usually close to neutral, because the expenses the benefit is reimbursing are themselves deductible business expenses in the same period, and the two largely offset. The point to take from it is that the benefit is not a tax-free windfall and should not be budgeted as one.
Where it does not overlap. Business interruption insurance pays only when a covered property loss shuts the business down, so a disabled owner triggers nothing under it. Group disability coverage pays employees, not the business. And a buy-sell arrangement funded with disability insurance buys out a permanently disabled owner's interest, which is a different event with a different payee.