HDHP Copays and Coinsurance After the Deductible

Once a high-deductible health plan enrollee meets the annual deductible, cost-sharing shifts from 100% out-of-pocket payment to shared responsibility between the enrollee and the insurer — typically through copays, coinsurance, or a combination of both. Understanding exactly how these mechanisms function under an HDHP differs from understanding them under a traditional PPO or HMO, because IRS rules governing HDHP eligibility constrain when and how first-dollar benefits can be applied. This page covers the definitions of copays and coinsurance in the HDHP context, how each operates after the deductible is satisfied, worked examples across common care scenarios, and the structural boundaries that determine which cost-sharing design applies.

Definition and scope

A copay is a fixed dollar amount charged for a covered service at the time of care — for example, $30 for a specialist office visit. A coinsurance charge is a percentage of the allowed cost for a service — for example, 20% of a $500 outpatient procedure.

Under a standard insurance plan, copays frequently apply from the first day of coverage regardless of whether a deductible has been met. Under an HDHP, the IRS prohibits the plan from paying benefits for most non-preventive services until the statutory minimum deductible is satisfied (IRS Revenue Procedure, updated annually via IRS Notice). For 2024, IRS Notice 2023-37 set the minimum annual deductible at $1,600 for self-only coverage and $3,200 for family coverage. Until those thresholds are crossed, the enrollee pays the full contracted rate — not a copay or coinsurance split.

Once the deductible is met, the plan begins sharing costs. The specific cost-sharing structure — whether copays, coinsurance, or a tiered combination — is set by the plan document and varies by insurer and employer plan design. The scope of this page is limited to what occurs after deductible satisfaction, not before.

How it works

After the deductible is satisfied, cost-sharing under a typical HDHP follows a sequential structure:

Deductible satisfied — the enrollee has paid the full minimum deductible amount (e.g., $1,600 for self-only in 2024) out of pocket for covered in-network services.
Cost-sharing activates — the plan begins paying its share of covered services; the enrollee pays either a fixed copay or a percentage (coinsurance) depending on service type.
Out-of-pocket maximum applies — once total enrollee spending (deductible + copays + coinsurance) reaches the plan's out-of-pocket maximum, the insurer covers 100% of covered in-network services for the remainder of the plan year. For 2024, IRS-set maximums are $8,050 for self-only and $16,100 for family coverage (IRS Notice 2023-37).

The distinction between copay-based and coinsurance-based designs is meaningful in practice:

Feature	Copay Design	Coinsurance Design
Cost structure	Fixed dollar amount per visit	Percentage of allowed charge
Predictability	High — enrollee knows cost in advance	Lower — depends on negotiated rate
Common service application	Office visits, urgent care	Surgery, imaging, hospitalization
Impact of high-cost services	Capped at copay regardless of cost	Scales with the total bill

Reviewing the HDHP out-of-pocket maximums and annual limits is essential context for understanding when cost-sharing ends entirely for the plan year.

Common scenarios

Scenario 1: Primary care office visit
An enrollee with a $1,600 self-only deductible has already paid $1,600 in covered claims. The plan carries a $25 copay for primary care visits after the deductible. The enrollee pays $25 at the visit; the plan pays the remainder of the contracted rate. No coinsurance applies to this service tier.

Scenario 2: Outpatient surgery
Same enrollee undergoes an outpatient knee procedure with a negotiated allowed amount of $4,200. The plan applies 20% coinsurance after the deductible. The enrollee's share is $840 (20% × $4,200). If the enrollee's year-to-date out-of-pocket total including the $840 reaches $8,050, all remaining covered services are paid at 100% by the plan through year-end.

Scenario 3: Prescription drugs after deductible
HDHP prescription drug cost-sharing varies significantly by plan design. Some plans apply a tiered copay structure (e.g., $10 generic / $40 brand-name / $80 non-preferred) after the deductible. Others apply coinsurance (e.g., 15% for generics, 30% for brand-name). Enrollees with chronic conditions managing ongoing prescriptions should review the HDHP and prescription drug costs structure carefully, as drug costs frequently represent the largest post-deductible expense category.

Scenario 4: Emergency care
In-network emergency department visits often carry a copay (frequently $150–$350) or a coinsurance percentage after the deductible. Out-of-network emergency visits are subject to different rules — some plans waive the out-of-network differential for true emergencies under ACA requirements, while others apply a separate out-of-network coinsurance rate. See HDHP emergency care coverage for the regulatory framework governing these situations.

Decision boundaries

Several structural factors determine which cost-sharing rules apply to a given service:

Network status — in-network and out-of-network services carry separate deductibles, coinsurance rates, and out-of-pocket maximums in most HDHP designs. Out-of-network coinsurance of 40%–50% is common even after in-network deductible satisfaction.
Service category — preventive care mandated under the ACA is covered before the deductible at $0 cost-sharing for in-network services; this is not affected by whether the deductible has been met. All other covered services generally require deductible satisfaction first.
Family vs. self-only enrollment — under an HDHP with family coverage, two deductible structures exist: an individual embedded deductible (if the plan uses one) and the full family deductible. Cost-sharing for a specific family member activates either when that member satisfies the embedded individual deductible or when the full family deductible is met, depending on plan design. The HDHP pediatric and family coverage page addresses embedded vs. aggregate deductible structures in detail.
HSA interaction — copays and coinsurance paid after the deductible are qualified medical expenses under IRS Publication 502, meaning HSA funds can be used to pay them tax-free (IRS Publication 502). This is a core feature of the HDHP-HSA pairing and is explained further on the HSA qualified medical expenses page.

Enrollees evaluating total annual cost exposure should account for both the deductible and the post-deductible cost-sharing layers. The full overview of HDHP cost structure is available at hdhpauthority.com.

References

The law belongs to the people. Georgia v. Public.Resource.Org, 590 U.S. (2020)