User Guide & Instructions

Enter your plan design on the Calculator tab: pick the desired metal tier; set the deductible, out-of-pocket maximum (MOOP), and default coinsurance; then add any service-specific copays or coinsurance. Coinsurance is always the issuer's share (the percentage the plan pays). Preventive care is always 100% covered, and employer HSA contributions count toward AV.

How cost-sharing is modeled: three phases

The calculator splits spending into three phases, and the rules differ in each:

• Deductible phase (before the deductible is met): the only member cost-sharing available is a copay. Coinsurance is not supported below the deductible. A service that is not subject to the deductible and has no copay is treated as 100% covered until the deductible is reached through other spending.
• Coinsurance phase (after the deductible, before the MOOP): either a copay or coinsurance applies — never both.
• After-MOOP phase: the plan pays 100%.

The two checkboxes (this is where most confusion lives)

Each service has Subject to Deductible and Subject to Coinsurance. Combined with the copay field, they express every common design:

Gotchas worth knowing

• A copay plus “subject to coinsurance” is redundant. Above the deductible, coinsurance governs and the copay is ignored — a copay and a coinsurance rate can't both apply. So adding a copay to a service that's subject to coinsurance barely moves AV (often under 0.1 point). If you want the copay to actually matter, uncheck “subject to coinsurance.” (Official FAQ Q6, Q7.)
• A copay that's subject to the deductible is less generous than no copay. The member pays the copay, and only the remaining cost counts toward the deductible — so it takes longer to reach the deductible. (FAQ Q19; Appendix Table 1.)
• Subjecting a benefit to the deductible can sometimes raise AV. In low-deductible plans with generous coinsurance, it can push the member into the more generous coinsurance range faster. (FAQ Q17.)
• Coinsurance can't be applied before the deductible. To model coinsurance in the deductible range, enter an effective copay equal to what the member would pay. (FAQ Q16.)

Other behaviors to be aware of

• Office visits & X-rays split. If primary-care/specialist visits use non-default cost-sharing but X-rays keep the default, an office visit including an X-ray applies the office-visit cost-sharing to both parts.
• Outpatient facility/professional override. The Outpatient Facility Fee and Outpatient Surgery Physician/Surgical Services cost-sharing can override the default cost-sharing of five services (MH/SUD, imaging, speech therapy, OT/PT, labs). Enter any non-default value on the service itself to keep its own cost-sharing. (FAQ Q21.)
• HSA/HRA credit is capped at the deductible (accounting for member cost-sharing below it).
• 2027: the MOOP limit is no longer enforced. The 2027 self-only limit is $12,000 — the calculator computes above it, but such a plan still isn't compliant.
• CSR / expanded bronze auto-selects the continuance table (94% → Platinum, 87% → Gold, 73% → Silver; expanded bronze allows a +5/−2 range). Metal choice affects utilization, so the same design can compute slightly differently by tier.

The official instructions below are authoritative — see especially the FAQ and Appendix Tables 1–2 for the exact deductible/coinsurance-range rules.