Data sources & methodology

CostCoverBase runs entirely in your browser. You paste premiums, deductibles, and sample bills from your own Summary of Benefits or quotes. We do not call insurer APIs, Healthcare.gov, or invent network prices.

What every calculator assumes

• Results are planning estimates — not quotes, claims, or medical advice
• You supply the numbers (premium, deductible left, coverage %, claim amount)
• In-network allowed amounts are not looked up; use the figure on your EOB or quote
• Premiums usually do not count toward deductible or out-of-pocket maximum
• Waiting periods, exclusions, and annual/lifetime maximums may reduce real plan payments

Core formulas we use

• Premium share: monthly × (1 − employer %) × 12
• Deductible on a bill: min(bill, deductible remaining)
• Coinsurance: after deductible, you pay your % of the remaining allowed amount
• Dental / ortho share: deductible first, then coverage % on the remainder
• Pet claim: deductible first, then reimbursement % on the remainder
• COBRA: full premium × (1 + admin %), or Code DD ÷ 12 × (1 + admin %)
• Worth-it / break-even: compare premiums + claim OOP vs paying claims cash

What we intentionally omit

• ACA premium tax credits and ZIP-based marketplace quotes
• Provider networks, prior authorization, and medical necessity
• Balance billing, surprise-billing disputes, and state balance-billing laws in full
• Drug formulary tiers beyond a flat prescription copay model
• Investment returns on an HSA or “savings jar” alternative to pet insurance

How we update

1. Formulas live as pure functions with regression tests in the repo.
2. Open-enrollment wording and disclaimers are reviewed when plan-year language changes in common SBCs — we do not scrape carrier sites for rates.
3. If a calculator disagrees with your plan documents, trust the plan documents and email contact@costcoverbase.com with the page URL and inputs.

Not insurance or medical advice

These tools help you compare scenarios with numbers you already have. Enrollment decisions, claims, and care choices belong with your insurer, HR, and licensed clinicians.