1. A commercial umbrella policy provides:

Excess limits above underlying policies and may drop down to cover some gaps

An umbrella provides excess limits over underlying policies and can provide broader coverage (subject to a self-insured retention) for some gaps.

2. Professional liability (errors and omissions) insurance covers liability arising from:

Negligent acts, errors, or omissions in rendering professional services

E&O / professional liability covers economic loss to others caused by the insured's negligent professional acts, errors, or omissions.

3. Directors and officers (D&O) liability insurance protects:

An organization's directors and officers against claims arising from their management decisions

D&O insurance covers directors and officers (and often the entity) for claims alleging wrongful acts in their management roles.

4. Employment practices liability insurance (EPLI) covers claims such as:

Wrongful termination, discrimination, and harassment

EPLI responds to employment-related claims like wrongful termination, discrimination, harassment, and retaliation.