How carrier ownership affects a medical malpractice policy.
How stock insurers, mutual insurers, reciprocal exchanges, and interindemnity arrangements differ.
Medical malpractice programs can have shareholders, policyholders, or subscriber members. The legal form can affect governing documents, assessments, benefits, and regulatory status. It does not predict price, claims handling, solvency, or coverage.
Compare four ownership structures
A stock insurer is owned by shareholders. The shareholders have the economic interest in the company.
A mutual insurance company is owned by its policyholders.
A reciprocal exchange is a subscriber-owned exchange of insurance contracts. Subscribers insure one another through an attorney-in-fact acting under the applicable powers of attorney and agreements.
An interindemnity arrangement is an unincorporated member arrangement with a trust agreement governing fund collection and disposition. It is not simply another type of insurer or policy.
Among licensed writers reported in CDI's 2025 direct-written-premium data for medical-malpractice lines, The Doctors Company reported 42.4 percent and MIEC reported 7.0 percent. That report does not measure every nonadmitted, risk-retention-group, captive, or interindemnity arrangement.
Member-owned carriers can return surplus
A mutual or reciprocal's governing documents can address surplus, dividends, or member benefits. Availability and allocation depend on the particular policy, subscriber terms, governing body, and applicable law.
A dividend or benefit is not guaranteed. Do not treat a past distribution as a future premium credit or policy benefit.
The Doctors Company reports a Tribute Plan for eligible members. In a July 2025 press release, the company stated that the program had paid more than $200 million to more than 15,000 members. That is a carrier-reported historical milestone, not a current eligibility finding or future payment promise. Read the current plan terms before including any possible benefit in a comparison.
Check whether the policy is assessable
An assessable policy, membership, or interindemnity arrangement can require the insured or member to pay an additional amount after the initial premium or contribution. The actual assessment obligation comes from the applicable governing documents and law.
Read the policy, subscriber or membership agreement, and any assessment terms. Ask for a written explanation, but compare it with the governing documents; a response does not amend them.
CAP/MPT uses a different structure
The Cooperative of American Physicians and Mutual Protection Trust is an unincorporated interindemnity arrangement under California Insurance Code section 1280.7. The statute says a qualifying arrangement is not an insurance policy or insurer; it remains subject to the statute's specific trust, financial-reporting, membership, and assessment rules.
CAP/MPT is not measured as an admitted insurer in CDI's market-share workbook. Its trust agreement and assessment agreement, rather than an admitted-policy rate filing, require direct review.
Compare the trust agreement with an insurance policy. Review the indemnity promise, assessments, termination and retirement terms, claim process, member obligations, and personal-assessment exposure. Under section 1280.7, trustees can assess participating members for stated obligations, subject to the governing terms.
Ask the document and money questions
Ask these questions for every carrier or program:
- What is the named insurer or arrangement, and what document creates the rights: policy, subscriber agreement or power of attorney, or trust agreement?
- Is there an assessment obligation or stated cap, and what happens on death, retirement, disability, nonpayment, or withdrawal?
- For a reciprocal, do the policy and subscriber documents limit a subscriber's maximum payment as permitted by the governing terms?
- Is any dividend, Tribute benefit, or member payment written, current, and separate from coverage?
Ownership does not determine policy quality. It can reveal financial interests and obligations that do not appear in an annual premium, but the actual coverage and member obligations remain in the governing documents.