Health Insurance Exam Math: Deductible and Coinsurance

A health insurance question gives you three amounts: a deductible, a coinsurance percentage, and an out-of-pocket maximum. Which one applies first?

For a covered service subject to the deductible under the simplified plan used here, first apply the remaining deductible, then calculate the member's coinsurance on the remaining allowed amount, and finally check the remaining applicable out-of-pocket limit. Already-paid amounts matter: the full annual deductible is not charged again on every claim.

The examples below are fictional insurance-license practice, not benefit estimates or medical advice. They assume one individual, one plan year, covered in-network services, and no coordination of benefits. Each example states the relevant plan provisions rather than treating them as universal.

Deductible vs. coinsurance vs. out-of-pocket maximum

HealthCare.gov explains that a deductible is a covered-expense amount the member pays before the plan begins sharing costs for services subject to it. Some services have different treatment. A plan may also have separate or family deductibles, so the word “deductible” does not by itself describe every claim.

Coinsurance is a percentage of covered costs. Read whose percentage is stated. “Member pays 20%” and “plan pays 80%” describe complementary shares in the examples here, not two separate member charges.

The out-of-pocket limit caps applicable member cost sharing for covered in-network benefits over a plan year. It does not make premiums or every noncovered expense disappear. We use a fictional limit below, not a statutory annual maximum.

Deductible and coinsurance worked examples: four successive claims

Fictional plan: $1,500 annual deductible; member pays 20% coinsurance after the deductible; $4,000 annual in-network out-of-pocket maximum. Deductible and coinsurance payments count toward that maximum. There are no copays, no prior claims, and no excluded charges in this sequence.

Claim 1: allowed amount of $900

All $900 falls below the remaining $1,500 deductible. Member pays $900; plan pays $0.

After this claim, the remaining deductible is $600. Accumulated qualifying out-of-pocket spending is $900. Do not reset either figure before the next claim.

Claim 2: allowed amount of $3,600

The first $600 completes the deductible. That leaves $3,000 to share.

Member coinsurance = $3,000 × 20% = $600. Add the deductible portion: member pays $1,200 total for Claim 2. Plan pays the other $2,400.

Accumulated member spending is now $900 + $1,200 = $2,100. The deductible is fully met, and $1,900 remains before the applicable out-of-pocket maximum.

A $720 coinsurance calculation would wrongly apply 20% to the entire $3,600, including dollars assigned to the deductible.

Claim 3: allowed amount of $12,000

With the deductible satisfied, ordinary member coinsurance would be $12,000 × 20% = $2,400. But only $1,900 remains under the out-of-pocket limit.

Member pays $1,900, bringing accumulated qualifying spending to $4,000. Plan pays $10,100 of the allowed amount. Do not report $2,400 simply because the percentage calculation was correct: the limit is another condition in the problem.

Claim 4: allowed amount of $800

The same plan-year maximum has been reached, and this claim is another covered in-network benefit under the stated assumptions. Member pays $0; plan pays $800.

The final check is $17,300 in allowed claims = $4,000 from the member + $13,300 from the plan. The table reconciles both claim by claim and across the year.

Allowed amount vs. billed charge: which number do you use?

Separate example: A participating provider bills $9,000. The contractual allowed amount is $6,000. The question states that the $3,000 difference is a contractual write-off, not billable to the member. The remaining deductible is $1,000, member coinsurance is 20%, and the out-of-pocket maximum will not be reached.

Apply $1,000 to the deductible. Of the remaining $5,000 allowed amount, the member pays 20%, or $1,000. Total member payment is $2,000; plan payment is $4,000.

The $3,000 write-off belongs to neither payment. Do not add it to the deductible or to the member's coinsurance base. Also do not assume every difference between billed and allowed amounts is a write-off in every setting. That treatment was an explicit condition of this example.

Copay vs. coinsurance: do not add an unstated charge

A copay is a fixed amount, rather than a percentage. Suppose an office visit has a $35 copay, and the question explicitly states that the deductible does not apply, no coinsurance is due for this visit, and the out-of-pocket cap is not close to being reached.

The member pays $35. Adding 20% coinsurance because another example used it would invent a plan provision. A question can state a different arrangement, so determine the treatment of that particular benefit.

Likewise, a premium is a payment for coverage, not another covered claim. Under the HealthCare.gov explanation cited above, premiums do not count toward the out-of-pocket maximum. Keep them separate if a question asks for total annual spending including premiums.

Health insurance calculation practice questions

Each question starts fresh. Do not carry balances over from the four-claim sequence.

A. Allowed amount is $4,000. Remaining deductible is $500. Member coinsurance is 30%. The out-of-pocket limit is not reached. What do member and plan pay?

B. The deductible is met. Allowed amount is $8,000. Member coinsurance is 25%, but only $700 remains under the applicable out-of-pocket maximum. What do member and plan pay?

C. An allowed $450 expense is subject to a remaining deductible of $600. The out-of-pocket limit is not reached. How much deductible remains afterward?

Answers

A: Share $3,500 after the $500 deductible. Member pays $500 + ($3,500 × 0.30) = $1,550. Plan pays $2,450. Together: $4,000.

B: Ordinary coinsurance is $2,000, but the applicable remaining cap is $700. Member pays $700; plan pays $7,300.

C: Member pays $450; plan pays $0. The remaining deductible is $150. No coinsurance is charged on an amount that never got past the deductible in this example.

Insurance exam questions about the payment order

Does "80/20 coinsurance" mean the member pays 80%?

Read which party is assigned each share. If the question says the insurer pays 80% after the deductible, the member share is 20%. Multiplying by the larger percentage because it appears first reverses the parties. HealthCare.gov defines coinsurance as the insured person's percentage share of a covered service, subject to the plan's terms.

Does the deductible count toward the out-of-pocket maximum?

For the covered, in-network benefits in this teaching plan, yes. It is part of counted member spending, not an additional amount on top of the stated maximum. The out-of-pocket glossary also explains important exclusions, including premiums and costs for services the plan does not cover. Do not apply a maximum to every dollar a person spends on health care.

Do you start the deductible over for each claim?

Not in this article's single-member, single-plan-year examples. Carry the remaining deductible forward. Start again only when a new independent question says to reset the plan, or when the stated terms require it. A per-claim deductible and an annual deductible are different arrangements.

Can I use the answer key to estimate my own medical bill?

No. The exercises omit plan-specific issues such as separate benefit deductibles, family accumulation rules, network treatment, exclusions, and services covered before the deductible. These are insurance licensing practice calculations, not benefit determinations or medical advice. For a real claim, use the policy and explanation of benefits rather than substituting this simplified plan.

What to do with an ambiguous question

An unexplained “80/20 plan,” a deductible with no prior-payment history, or a bill with no allowed amount may leave essential information missing. Identify the missing assumption instead of pretending that every plan uses the same rules. In an exam, use the instructions and policy excerpt provided with the item.

Review the broader Life and Health Insurance topic, then try the general insurance practice test. For a different kind of limit, study auto liability split limits. Health cost sharing limits the member's applicable spending; liability policy limits cap the insurer's applicable payment. They are not interchangeable ideas.