HSA vs. FSA for Construction Workers: Choosing the Right Account for a Mobile, Seasonal Workforce

When construction employers add a health savings account or flexible spending account to their benefits package, the communication challenge is immediate: these accounts have rules that hit very differently for workers who change contractors mid-season, take time off between projects, or work variable hours throughout the year. A worker who stays with one employer for the entire plan year and uses their FSA without incident may have a completely different experience than a framing crew member who moves from one general contractor to another and wants to carry their health account with them.

HSAs and FSAs both reduce the after-tax cost of health care for employees. That is where the similarity ends. The accounts have different ownership structures, different portability rules, different contribution limits, different rollover treatment, and different eligibility requirements tied to the health plan type the employee is enrolled in. Getting these distinctions wrong in your open enrollment communications costs employees money and creates avoidable HR problems at exactly the moments, mid-season departures and seasonal layoffs, when your team has other things to worry about.

This guide focuses on how HSA and FSA rules apply specifically to construction and trade workforces, including seasonal employees, project-based workers who move between contractors, and business owners who carry both a group plan and an individual coverage arrangement. The goal is to give you enough detail to explain the rules clearly at open enrollment, and to make the right design choice when you are building or renewing your benefits package.

How HSAs and FSAs Work: The Basics

Health Savings Accounts

An HSA is a tax-advantaged savings account that an individual opens, owns, and controls. Contributions are deductible or excluded from income if made through payroll. Growth in the account is tax-free. Withdrawals for qualified medical expenses are tax-free. The triple tax advantage makes the HSA the most tax-efficient health spending vehicle available in the U.S. tax code for those who qualify.

The central eligibility rule: to contribute to an HSA, the account holder must be enrolled in a qualifying high-deductible health plan as their only health coverage during the months of contribution. They cannot be covered by Medicare, cannot be claimed as a dependent on someone else's taxes, and cannot have any other health coverage that does not qualify as an HDHP. The IRS sets minimum deductible and maximum out-of-pocket thresholds annually to define what counts as an HDHP.

There is no employer sponsorship requirement. Any eligible individual can open an HSA at a bank, credit union, or brokerage. But many employers offer payroll deduction and employer contributions to make the account more accessible and to capture the additional FICA tax savings available only through payroll. Employer contributions are excluded from the employee's income and are not subject to payroll taxes, which improves the total economics of the arrangement compared to after-payroll contributions.

The annual contribution limit is set by the IRS each fall and applies to the combined total of employee and employer contributions. The limit differs for self-only HDHP coverage versus family HDHP coverage. Funds in an HSA roll over indefinitely. There is no annual deadline to use the balance. Unspent balances grow and can be invested once the account reaches a threshold set by the custodian, making the HSA function as both a current-year spending account and a long-term health care savings vehicle.

Health Care Flexible Spending Accounts

A health care FSA is an employer-sponsored benefit plan that allows employees to set aside a portion of their salary on a pre-tax basis to pay for eligible medical expenses. The FSA is part of the employer's Section 125 cafeteria plan. It is not owned by the employee in the same way an HSA is. The account exists within the employer's plan structure and is subject to the employer's plan terms.

FSA elections are made during open enrollment and generally cannot be changed during the plan year unless the employee experiences a qualifying life event such as marriage, divorce, birth of a child, or a change in employment status. The full annual election amount is available to the employee at the start of the plan year, even though contributions are collected through payroll throughout the year. If an employee elects $2,000, uses $1,800 by March, and then leaves the company in April, the employer absorbs the difference between contributions collected and expenses reimbursed.

The use-it-or-lose-it rule means balances that are not used by the end of the plan year are forfeited. Employers may offer one of two optional relief provisions: a rollover of up to the IRS annual limit (currently capped by IRS guidance and indexed occasionally) that carries into the next plan year, or a two-and-a-half month grace period that extends the spending deadline into the new year. Employers can offer one or the other but not both. If your plan offers neither, employees risk losing unused balances at year-end. Most employers who understand the retention impact of FSA forfeitures add the rollover provision at the next plan renewal.

The Critical Difference for Construction Workers: Portability

For a worker who stays with the same employer throughout the plan year, the portability distinction matters less. For construction workers who move between contractors, change employment mid-season, or leave for several months in the off-season, portability is the most important factor in choosing between the two accounts.

When a Worker Changes Employers

An HSA follows the employee. If a project foreman leaves one contractor in August and starts with a new one in October, the HSA account stays open and accessible throughout. The worker can continue spending from the account for qualified expenses even during the gap between employers. They cannot make new contributions during any months when they are not enrolled in a qualifying HDHP, but the existing balance remains available without restriction. When they re-enroll in an HDHP through the new employer, contributions resume up to the annual limit, prorated for the months of HDHP coverage if the account was not active for the full year.

An FSA does not work this way. An FSA is tied to the employer's Section 125 plan. When employment ends, FSA participation ends. Any balance remaining in the account at termination is forfeited unless the departing employee elects COBRA FSA continuation, which allows them to continue contributing to and spending from the account on an after-tax basis through the end of the plan year. Because after-tax FSA contributions eliminate the primary benefit of the account, most departing employees do not elect COBRA FSA continuation in practice.

The practical takeaway: if a meaningful portion of your field workforce changes employers during the year, which is common in construction, an HSA-based benefits design protects workers' health spending dollars more effectively than an FSA.

When a Worker Goes Seasonal

Seasonal construction workers who are enrolled in your plan during active employment and then go off the plan during the off-season face a similar pattern. During the period when they are no longer enrolled, FSA access ends. Their HSA, by contrast, remains open and accessible. Any unspent balance from the working months is available to cover medical expenses during the off-season, even though the worker is not currently enrolled in your HDHP.

There is one nuance: during months when the seasonal worker is not enrolled in any qualifying HDHP, they cannot make new contributions to their HSA. This limits annual accumulation for workers with long off-seasons. But they can still spend from the existing balance, which is typically the more immediate concern for workers between projects who face unexpected health expenses during the gap.

Plan Type Drives HSA Eligibility

The biggest constraint on using HSAs in a construction benefits package is not employee preference. It is the plan type. To contribute to an HSA, the employee must be enrolled in a qualifying HDHP as their only health coverage during the contribution months. If your group health plan is a PPO with a low deductible, no one enrolled in that plan can use an HSA regardless of how the option is communicated or marketed.

HDHP Minimums and the IRS Threshold

An HDHP is defined by IRS thresholds that apply to both the minimum annual deductible and the maximum out-of-pocket. The IRS publishes these thresholds annually. Plans with deductibles at or above the minimum and out-of-pocket maximums at or below the IRS ceiling qualify as HDHPs. Employees enrolled in qualifying HDHPs can open and contribute to HSAs during those months of coverage.

Many construction employers who moved to level-funded health plans in recent years are already on plans that meet the HDHP thresholds, sometimes without making it a conscious design choice. If that describes your plan, your employees may already be HSA-eligible. Confirming HDHP status with your TPA or broker and communicating HSA eligibility at the next open enrollment can unlock a benefit that workers are currently missing.

FSA Compatibility With Most Plan Types

A general-purpose health care FSA can be offered alongside most group health plan types, including PPOs, HMOs, and POS plans, as well as level-funded plans that do not meet the HDHP thresholds. The constraint is that a general-purpose FSA cannot be offered to employees who are also contributing to an HSA, because the general FSA disqualifies HSA eligibility during the same period.

Employers who want to offer both must offer a limited-purpose FSA that covers only dental and vision expenses. A limited-purpose FSA is compatible with HSA eligibility because it does not provide the kind of general health coverage that conflicts with the HDHP-only requirement.

This design question matters for construction employers with a mixed plan enrollment, for example, where some employees are on an HDHP-compatible level-funded plan and others are on a traditional PPO through a union or alternate arrangement. Offering a general FSA to the entire workforce without a limited-purpose carve-out would disqualify the HDHP enrollees from making HSA contributions, even if they are otherwise eligible.

Construction-Specific Scenarios

The Project-Based Worker Who Changes Contractors Three Times in a Year

This scenario is more common in construction than in most other industries. A project superintendent might work for one general contractor through the spring, transition to a specialty subcontractor for a summer build-out, and then join another general contractor for a fall commercial project. Each transition may involve a gap in coverage or a re-enrollment in a new group plan.

If each employer offers an HDHP-compatible plan, the superintendent's HSA travels through all three transitions. They contribute up to the prorated annual limit for the months they are enrolled in a qualifying HDHP. The account never resets or forfeits. A worker who follows this pattern for five years and contributes consistently can accumulate a meaningful balance that provides financial resilience during future coverage gaps or high-cost health events.

An FSA, by contrast, resets with each employer change. Any unused balance from employer one is forfeited when the worker leaves (subject to COBRA FSA election rights). Employer two may or may not offer an FSA, and if they do, the election starts fresh. The total tax savings from FSA contributions during any single employment period is real but limited, and the forfeiture risk at each employer transition reduces the net benefit meaningfully over a multi-contractor career.

The Seasonal Crew Member on a Six-Month Plan

For a seasonal worker enrolled in your group plan from April through October, an FSA election creates an immediate tension: the election applies to the plan year, but the worker's access to the account ends when employment ends. If they elect $1,500 and use $800 by the time they terminate in October, the remaining $700 is likely forfeited or available only via COBRA FSA election at after-tax cost.

An HSA is cleaner for this scenario. The seasonal worker contributes for the six months of HDHP enrollment, spending as needed during that window. When they go off the plan, contributions stop but the account remains open. They can use the remaining balance during the off-season for any qualified medical expense. When they re-enroll in the spring, contributions resume. There is no annual election event, no use-it-or-lose-it risk tied to the employment end date, and no forfeiture at termination.

If your seasonal workers tend to have predictable medical spending during the enrollment period and typically use most of their FSA balance before leaving, an FSA can still work reasonably well. But the default for construction benefits designers serving a seasonal workforce should favor HSA-eligible plan designs wherever the plan type permits it.

The Owner Who Carries Both a Group Plan and an ICHRA

Some construction business owners operate through a structure where they take individual market coverage reimbursed through an ICHRA while offering group coverage to their field employees. This creates an HSA eligibility question: can the owner contribute to an HSA while receiving ICHRA reimbursements for individual market premiums?

The answer depends on what the ICHRA reimburses. If the owner is enrolled in an individual market HDHP and the ICHRA reimburses those premiums, the owner may be HSA-eligible, provided the ICHRA does not also reimburse non-HDHP expenses that would disqualify the HDHP arrangement. If the owner is enrolled in an individual plan that does not qualify as an HDHP, HSA contributions are not permitted. This is a design question worth reviewing with a qualified benefits advisor before setting up the arrangement, since the interaction between ICHRA reimbursements and HSA eligibility is nuanced and fact-specific.

Contribution Limits and the Annual Election Process

The annual contribution limits for both HSAs and health care FSAs are set by the IRS and adjusted each fall for inflation. For HSAs, the limit covers all contributions to the account during the year from both the employee and the employer combined. For FSAs, the limit covers the employee's annual salary reduction election; employer contributions are permitted on top of that, though most employers do not supplement FSA elections with employer dollars.

HSAs generally allow higher total contributions than health care FSAs, particularly for family coverage. The HSA family limit is roughly double the self-only limit and is meaningfully higher than the FSA cap. For a worker trying to set aside the maximum amount to cover anticipated health costs, the HSA provides more contribution room in a single year and carries over indefinitely. The FSA resets annually and caps at a lower threshold, which limits its value for workers with higher medical spending needs or who want to accumulate a buffer for future expenses.

If you want to make employer contributions to encourage participation, both accounts accept them. Employer HSA contributions belong to the employee permanently and follow them to any future employer. Employer FSA contributions are forfeited if unused at year-end and do not travel with the employee at separation. For construction employers with meaningful workforce turnover, this distinction shapes the return on any employer contribution you put into the accounts.

Which Account to Default to for Your Construction Workforce

For most construction employers who have the flexibility to design around either account type, the framework looks like this:

Default to HSA-eligible plan design if your plan type permits. If you are on a level-funded or self-insured arrangement that meets HDHP thresholds, communicate HSA eligibility and support contributions through payroll. The portability and rollover rules make HSAs better for workers who move between contractors, go seasonal, or want to build health care savings over a career. The administrative overhead is minimal since the HSA is owned and managed by the employee through a bank or custodian rather than administered by your HR team.

Offer a limited-purpose FSA alongside the HSA for dental and vision coverage. A limited-purpose FSA covers dental and vision expenses only and is fully compatible with HSA eligibility. This combination (HDHP with HSA and limited-purpose FSA) is the most tax-efficient design available for construction employers and gives workers a way to pre-fund predictable dental and vision costs without sacrificing HSA eligibility.

Use a general-purpose health care FSA only if your plan type does not qualify as an HDHP. If you are on a traditional PPO with a low deductible, HSAs are not available to your enrolled employees and a general FSA is the appropriate tax-advantaged spending vehicle. In this case, communicate the use-it-or-lose-it rules clearly at open enrollment and encourage conservative elections from workers who may have unpredictable employment continuity across the plan year.

Flag FSA forfeiture risk to seasonal workers at enrollment. A seasonal employee who elects $2,000 to a general FSA in January and leaves the company in June has likely forfeited a significant portion of that election. If your group includes seasonal employees who will not be enrolled for the full plan year, either advise conservative FSA elections from that population or confirm that your plan design includes the rollover provision to limit the forfeiture exposure.

Use the Benefits ROI Calculator to model how different account structures compare in terms of total cost to your company and total value to employees across your workforce mix.

Related Reading

For additional context on building benefits packages for construction and trade workforces:

• Building a Benefits Package for Mid-Size Employers: Retention Strategy and Cost Control
• Dental and Vision Benefits for Mid-Size Employers: The Retention Case
• Benefits-Driven Turnover: When the Insurance Package Is the Reason Workers Leave

Frequently Asked Questions

Can we offer both an HSA and an FSA to the same employee?

A general-purpose health care FSA disqualifies the employee from contributing to an HSA in the same period. However, a limited-purpose FSA that covers only dental and vision expenses is fully compatible with HSA eligibility. If you want to give employees both options, offer the HDHP for HSA eligibility and pair it with a limited-purpose FSA for dental and vision. This combination is legal, common in construction benefits packages, and gives employees maximum flexibility without creating a conflict between the two accounts.

What happens to an employee's FSA when they leave mid-year?

FSA participation ends when employment terminates. Any balance remaining in the account is forfeited, unless the employer's plan offers a rollover provision that could carry a portion of the balance into the next plan year. The departing employee can elect COBRA FSA continuation, which allows them to continue contributing to and spending from the account on an after-tax basis through the end of the plan year. Because after-tax contributions eliminate the primary benefit of the FSA, most departing employees do not elect COBRA FSA continuation. Communicate this risk clearly at enrollment to seasonal workers and project-based hires so they can make appropriately sized elections.

Our health plan is level-funded. Does that mean our employees are HSA-eligible?

Not automatically. A level-funded plan may or may not qualify as an HDHP depending on its specific deductible structure and out-of-pocket maximum. Ask your TPA or broker whether your plan meets the current IRS HDHP criteria. If it does, employees enrolled in that plan can open and contribute to HSAs. If it does not meet the thresholds, a general-purpose FSA is the appropriate tax-advantaged spending vehicle. Many level-funded plans can be redesigned at renewal to meet HDHP criteria, which is worth exploring if HSA access would benefit your workforce.

How do we handle an employee covered by both our group plan and a spouse's plan?

An employee covered by your HDHP and also by a spouse's non-HDHP plan is not eligible to contribute to an HSA. The spouse's plan provides coverage that is not an HDHP, which disqualifies the employee from new HSA contributions during any months when that second coverage is in effect. The employee can still participate in a general FSA if your plan offers one, and they can spend from an existing HSA balance at any time, but they cannot make new contributions while covered by the spouse's non-qualifying plan. Including this situation in your open enrollment communications helps affected employees understand the rule before they elect HSA contributions that would not be permitted.

Can a worker contribute to their HSA during a gap between construction jobs?

Only if they are enrolled in a qualifying HDHP during that gap. Workers who lose group coverage at separation can elect COBRA continuation of their former employer's HDHP, which maintains HSA eligibility and allows continued contributions during the COBRA period. A worker who enrolls in an individual market HDHP during the gap, through an exchange or directly from a carrier, can also continue contributing. Workers who are uninsured during the gap or enrolled in a non-HDHP plan cannot make new contributions. Existing HSA balances remain available to spend on qualified medical expenses regardless of current coverage status, which is one of the key advantages of the account for a workforce with episodic employment gaps.