Insurance terminology decoded — the fine print in plain English

Reviewed by the How To Help Your Elders Team

Insurance paperwork uses precise language that makes perfect sense to the industry and almost none to everyone else. According to AARP, more than half of adults over 50 report difficulty understanding their health insurance benefits, and that confusion leads to missed coverage, surprise bills, and poor financial planning. This guide translates the terms you will encounter most often into plain language so you can read statements, estimate costs, and hold informed conversations with insurance representatives.

The Deductible Is What Your Parent Pays Before Insurance Starts Sharing Costs

The deductible is the amount of money your parent must pay out of pocket each year before the insurance company begins paying for covered services. If the deductible is $1,500, your parent is responsible for the first $1,500 of healthcare costs in a calendar year. Once that threshold is crossed, insurance starts sharing the bill.

Deductibles reset every January 1st. A $1,500 deductible paid in full by November means your parent has no deductible costs for the rest of that year, but starts over at $1,500 on January 1st. Plans with lower deductibles (maybe $500) have higher monthly premiums. Plans with higher deductibles (maybe $2,500 or more) have lower premiums. The trade-off is paying more each month for smaller upfront costs when care is needed, or paying less each month but absorbing a larger hit when something happens.

Some services are covered before the deductible is met. Preventive care like annual wellness visits and certain screenings are often covered at no cost regardless of deductible status. CMS requires that Medicare cover an annual wellness visit with no deductible or copay, and most private plans follow similar rules for preventive services under the Affordable Care Act.

Copay and Coinsurance Are Two Different Ways of Splitting the Bill

A copay is a fixed dollar amount your parent pays for a specific service. A $15 copay for a primary care visit means your parent pays $15 every time, whether the visit costs the insurance company $100 or $500. Copays are predictable and usually collected at the time of service.

Coinsurance works on a percentage basis. After the deductible is met, your parent and the insurance company split costs by percentage. If the plan has 20/80 coinsurance, your parent pays 20 percent of covered costs and insurance pays 80 percent. A $10,000 hospital stay under this arrangement means your parent owes $2,000 and insurance covers $8,000. Unlike a copay, the dollar amount of coinsurance varies with the cost of the service.

Many plans combine both. Your parent might pay a flat copay for routine doctor visits but coinsurance for hospital stays, surgeries, or specialist care. The plan's summary of benefits document spells out which cost-sharing method applies to each type of service. CMS requires all Medicare plans to provide a standardized summary, and most private insurers follow similar disclosure rules.

Prior Authorization Is Permission Before Treatment Happens

Prior authorization means the insurance company must approve a treatment, test, or medication before it will cover the cost. The doctor's office handles the request, contacting the insurance company with clinical documentation explaining why the service is medically necessary. The insurance company reviews it and approves, denies, or requests more information.

The process typically takes a few business days, though urgent requests are prioritized. According to the American Medical Association's 2023 prior authorization survey, 94 percent of physicians report that prior authorization causes delays in patient care. If your parent needs something time-sensitive, tell the doctor's office to flag the request as urgent. If a request is denied, the doctor can appeal by providing additional clinical evidence. CMS has been tightening timelines for prior authorization decisions in Medicare Advantage plans, requiring faster turnaround for urgent requests.

Without prior authorization when it is required, insurance can refuse to pay the entire cost, leaving your parent on the hook for the full bill. Before any major procedure, test, or new medication, confirming that prior authorization has been obtained or is not required prevents expensive surprises.

The Out-of-Pocket Maximum Puts a Ceiling on Annual Costs

The out-of-pocket maximum is the most your parent will pay for covered services in a single year. It includes deductibles, copays, and coinsurance. Once your parent hits this number, insurance pays 100 percent of covered services for the rest of that year.

If the out-of-pocket maximum is $5,000 and your parent has already paid $4,500 in combined deductibles and coinsurance, they owe only $500 more before insurance covers everything. This cap matters most in years with significant healthcare costs, and it provides a financial ceiling you can plan around.

The out-of-pocket maximum does not include monthly premiums, which your parent pays regardless. It also does not include charges for out-of-network providers or services that insurance does not cover at all. For 2025, CMS set the Medicare Advantage out-of-pocket maximum at $8,850, though many plans set lower limits. Knowing your parent's specific maximum helps you understand the worst-case annual cost.

In-Network Versus Out-of-Network Changes What You Pay

Insurance plans have networks of providers who have agreed to charge negotiated rates. Seeing an in-network doctor means lower costs. Seeing an out-of-network doctor usually means significantly higher costs or no coverage at all, depending on the plan.

The difference is substantial. An in-network doctor visit might cost a $15 copay. The same visit out-of-network might require 40 to 50 percent coinsurance with a separate, higher deductible. Some plans, particularly HMOs, do not cover out-of-network services at all except in emergencies. PPO plans typically cover out-of-network care at a reduced rate.

If your parent has a specialist they want to continue seeing, checking whether that doctor is in the plan's network before the coverage year starts prevents surprises. If your parent needs emergency care, federal law (the No Surprises Act, effective since 2022) protects against surprise billing from out-of-network providers in emergency situations, so emergency room care is covered at the in-network rate regardless of which hospital the ambulance reaches.

Reading the Explanation of Benefits Statement

When insurance processes a claim, they send an Explanation of Benefits (EOB) that shows what happened. It lists the service, what the provider charged, the "allowed amount" (what insurance considers a fair price for that service), what insurance paid, and what your parent owes. For in-network providers, the doctor writes off any difference between their charge and the allowed amount. Your parent only owes the copay, coinsurance, or deductible portion.

The EOB is not a bill. It is a record of how a claim was processed. A separate bill comes from the provider. Comparing the EOB to the bill catches errors, which are more common than you might expect. The CMS Office of Inspector General has repeatedly found billing errors in Medicare claims. If something on the EOB looks wrong, call the insurance company's customer service number on the back of the card.

Frequently Asked Questions

What is the difference between a copay and coinsurance?
A copay is a fixed dollar amount you pay per service ($15 for a doctor visit, for example). Coinsurance is a percentage of the cost you pay after meeting your deductible (20 percent of a hospital bill, for example). Copays are predictable; coinsurance amounts vary with the cost of care.

Does my parent's deductible reset every year?
Yes. Most health insurance deductibles reset on January 1st. Any amount your parent paid toward the deductible in the previous year does not carry over. Your parent starts fresh each calendar year.

What happens if insurance denies a prior authorization?
The doctor can appeal the denial by providing additional clinical information. You can also file a formal appeal with the insurance company. If the appeal is denied, some states allow external review by an independent third party. Do not accept a denial as final without exploring the appeals process.

Are premiums included in the out-of-pocket maximum?
No. Monthly premiums are separate from the out-of-pocket maximum. Premiums are the cost of having the insurance plan. The out-of-pocket maximum covers only deductibles, copays, and coinsurance for covered services.

How do I find out if a doctor is in my parent's network?
Call the number on the back of the insurance card or use the insurance company's online provider directory. Confirm with the doctor's office as well, because network participation can change. Checking before scheduling an appointment avoids surprise out-of-network charges.