From Insurance Lounge

Those whose employers do not provide benefits, and self-employed individuals who desire disability coverage, may purchase their own policies on the open market. Premiums and available benefits for individual coverage vary considerably between different companies, for individuals in different occupations, and by State and Country. In general, premiums are higher for policies that provided more monthly benefit, pay the benefit for a longer period of time, and start payments for benefits more quickly following a disability. Premiums also tend to be higher for policies that define disability in broader terms, meaning the policy would pay benefits in a wider variety of circumstances.