Enter Plan Inputs
Use the fields below to estimate annual HDHP cost under your employee benefits setup. Results appear above this form after submission.
Formula Used
Annual Employee Premium = Premium Per Pay Period × Pay Periods Per Year
Expected Non-Preventive Charges = Office/Lab Costs + Prescription Costs + Other Non-Preventive Costs + Unexpected Care Contingency
If Charges ≤ Deductible, Member Medical Cost = Charges
If Charges > Deductible, Member Medical Cost = Deductible + (Charges − Deductible) × Coinsurance Rate
Final Member Medical Cost = Lesser of calculated amount or Out-of-Pocket Maximum
HSA Tax Savings = Employee HSA Contribution × Marginal Tax Rate
Gross Annual Cost = Annual Employee Premium + Expected Member Medical Cost
Net Annual Cost = Gross Annual Cost − Employer HSA Contribution − Wellness Credit − HSA Tax Savings
Worst-Case Annual Cost = Annual Employee Premium + Out-of-Pocket Maximum − Employer HSA Contribution − Wellness Credit − HSA Tax Savings
Preventive care is displayed separately and assumed fully covered in-network. Adjust that assumption if your plan applies cost sharing differently.
How to Use This Calculator
- Enter a scenario name and choose the coverage tier.
- Provide your employee premium per pay period and number of pay periods.
- Enter the deductible, coinsurance rate, and out-of-pocket maximum.
- Add expected office, lab, prescription, and other non-preventive expenses.
- List preventive care separately for visibility, even if covered at 100%.
- Include employer HSA funding, your planned HSA contribution, tax rate, and any wellness rebate.
- Add a contingency amount if you want a more conservative estimate.
- Click the calculate button to show results above the form, review the chart, and export CSV or PDF summaries.
Example Data Table
| Scenario | Coverage | Premium/Pay | Pay Periods | Deductible | Coinsurance | OOP Max | Expected Charges | Employer HSA | Employee HSA | Tax Rate | Wellness Credit | Estimated Net Cost |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Starter HDHP | Individual | $120.00 | 24 | $2,000.00 | 20% | $4,500.00 | $3,600.00 | $750.00 | $1,200.00 | 22% | $200.00 | $3,986.00 |
| Family HDHP | Family | $275.00 | 24 | $4,000.00 | 20% | $8,000.00 | $9,000.00 | $1,500.00 | $3,000.00 | 24% | $400.00 | $8,980.00 |
| Low-Use HDHP | Individual | $85.00 | 24 | $1,600.00 | 10% | $3,500.00 | $900.00 | $500.00 | $800.00 | 22% | $100.00 | $2,164.00 |
FAQs
1. What does this HDHP cost calculator estimate?
It estimates annual employee cost for an HDHP by combining payroll premiums, expected medical spending, deductible and coinsurance exposure, employer HSA funding, wellness credits, and estimated HSA tax savings.
2. Does preventive care increase the member medical cost here?
No. The calculator shows preventive care separately and assumes qualifying in-network preventive services are covered at 100%. If your plan handles preventive care differently, update your assumptions manually.
3. Why are HSA contributions treated as offsets?
Employer HSA deposits directly reduce your economic burden. Employee HSA contributions create tax savings, so this tool subtracts only the estimated tax benefit, not the full contribution amount.
4. What is the difference between net annual cost and worst-case annual cost?
Net annual cost uses your expected claims. Worst-case annual cost assumes you reach the out-of-pocket maximum, then applies employer HSA funding, tax savings, and credits to estimate a high-cost year.
5. Should I include out-of-network claims here?
Only if you convert them into a reasonable estimated employee burden. Out-of-network rules often differ from in-network HDHP cost sharing, so this simplified model works best for in-network planning.
6. Can I compare multiple plan scenarios?
Yes. Change the scenario name, adjust the fields, and run the calculator again. Export each result as CSV or PDF to compare plans side by side later.
7. What tax rate should I enter?
Use your estimated combined marginal rate if you want a broader tax view, or only your federal marginal rate if you prefer a conservative estimate. Keep your approach consistent across plan comparisons.
8. Is this calculator suitable for employee benefit enrollment decisions?
It is useful for planning, comparisons, and budgeting. Still, final enrollment decisions should also consider provider networks, prescriptions, expected utilization, employer contributions, and official plan documents.