Key Takeaways
- Your monthly premium is only one piece of your true annual health insurance cost.
- Deductibles, copays, coinsurance, and out-of-pocket maximums can add thousands to your yearly bill.
- Employer contributions and HSA/FSA tax savings can significantly offset what you pay.
- Comparing plans on total estimated cost—not just premium—leads to smarter enrollment decisions.
- Gathering last year's medical spending data before enrollment makes your cost estimates far more accurate.
Summary
28 items · 30–60 minutes
Why You Need a Cost Worksheet Before You Enroll
Every fall, millions of Americans sit down for open enrollment and pick a health plan based almost entirely on the monthly premium—the amount deducted from each paycheck. It's the most visible number, so it feels like the most important one. But in my years as a benefits consultant, I've watched that shortcut cost people hundreds, sometimes thousands, of dollars they didn't budget for.
The truth is that your premium is just the entry fee. What you actually spend on healthcare in a given year depends on a much longer list of numbers: your deductible, copays, coinsurance, your plan's out-of-pocket maximum, and what your employer pays on your behalf. Add in tax-advantaged accounts like an HSA or FSA, and the math gets complicated fast.
This worksheet checklist is designed to slow you down in the best possible way. Work through it before you make any enrollment decision, and you'll walk into the comparison with real numbers instead of guesses. If you haven't yet pulled together your supporting paperwork, start with the documents to gather before open enrollment starts so you have everything on hand.
Once you've completed this worksheet, pair it with the broader open enrollment checklist to make sure you haven't missed any deadlines or coverage decisions along the way.
What You'll Need Before You Start
Before working through the checklist items below, gather the following. Most of this lives in your last year's Explanation of Benefits (EOB) statements, your pay stubs, and your employer's benefits guide. If you're new to a job or switching insurers, pull whatever records you have—even rough estimates are better than nothing.
Last Year's Explanation of Benefits (EOB) Statements
Tells you exactly how much you spent on healthcare last year, broken down by service type—your most accurate baseline for estimating future costs.
Employer Benefits Guide or Summary of Benefits
Lists premiums, deductibles, copays, coinsurance rates, and out-of-pocket maximums for each plan option available to you.
Plan Formulary (Drug List)
Shows which medications are covered under each plan and at which cost tier—essential if you take any prescription drugs.
Current Pay Stub
Confirms how much is currently deducted for health insurance each pay period and helps verify employer contribution amounts.
Provider Directory
Confirms which doctors, specialists, and hospitals are in-network for each plan you're considering.
IRS Publication 969 (HSA and FSA Contribution Limits)
Provides official annual contribution limits for Health Savings Accounts and Flexible Spending Accounts.
Spreadsheet or Comparison Template
Lets you record and compare cost figures side-by-side across multiple plan options during your analysis.
If you're considering a High Deductible Health Plan with an HSA, you'll want to look at the HDHP and HSA annual enrollment checklist alongside this worksheet. The tax math for those plans has its own layer of complexity that's worth tackling separately.
Don't Use Last Year's Premium as a Starting Point
Employers change their plan offerings, premium splits, and network arrangements every year. Even if you're re-enrolling in the same plan, the costs and terms may have changed significantly. Always pull fresh numbers from this year's benefits guide before filling out your worksheet.
FSA Funds Don't Roll Over Like HSA Funds Do
A Flexible Spending Account (FSA) is typically "use it or lose it" — any balance you don't spend by year-end is forfeited (some plans allow a small rollover or grace period). Factor this into how much you contribute. An HSA, by contrast, rolls over indefinitely and even earns interest.
Out-of-Network Costs Can Blow Your Budget
If you see a provider who is out of network, you may owe a much larger share of the cost — and in some plan types (like HMOs), out-of-network care isn't covered at all except in emergencies. Always verify network status before your appointment, not after.
The Annual Cost Worksheet Checklist
Work through each group below and write your numbers into a spreadsheet or notebook as you go. The goal is to end up with a side-by-side comparison for every plan you're considering. Don't skip groups that seem irrelevant—some items only matter if you use a lot of specialist care or prescription drugs, but you won't know that until you check.
Step 1: Capture Your Premium Costs
Step 2: Document Your Deductible
Step 3: Record Copays and Coinsurance
Step 4: Tally Prescription Drug Costs
Step 5: Identify Your Out-of-Pocket Maximum
Step 6: Account for HSA, FSA, and Employer Contributions
Step 7: Check Network and Provider Access
Step 8: Final Review Before You Enroll
Your Out-of-Pocket Maximum Is Your Financial Safety Net
Many people focus so hard on the deductible that they forget about the out-of-pocket maximum — the hard cap on what you'll pay in a plan year (not counting premiums). If you or a family member faces a serious diagnosis, hospitalization, or surgery, this number becomes the most important figure on your worksheet. Always run your comparison assuming a worst-case scenario where you hit the maximum, and make sure that number is one you could actually manage.
Once you have all your numbers filled in, you're ready to move to the next step: building your total cost estimate. The article calculating your total out-of-pocket health insurance costs for the year walks through exactly how to combine these inputs into a realistic annual figure for each plan you're comparing.
How to Use Your Numbers to Compare Plans
Once you've collected all the figures from the checklist, the comparison becomes straightforward arithmetic. Here's the basic formula for each plan you're evaluating:
| Cost Component | Plan A | Plan B | Plan C |
|---|---|---|---|
| Annual premium (your share) | $___ | $___ | $___ |
| Estimated deductible spending | $___ | $___ | $___ |
| Estimated copay/coinsurance spending | $___ | $___ | $___ |
| Estimated prescription drug costs | $___ | $___ | $___ |
| Gross estimated annual cost | $___ | $___ | $___ |
| Minus: Employer HSA/FSA contribution | ($___) | ($___) | ($___) |
| Minus: Your HSA/FSA tax savings | ($___) | ($___) | ($___) |
| Net estimated annual cost | $___ | $___ | $___ |
A plan with a higher monthly premium often wins on net annual cost if you have predictable, frequent medical needs—because a lower deductible means you stop paying full price for care sooner. Conversely, if you're generally healthy and rarely use healthcare, a high-deductible plan with a lower premium and employer HSA contribution may cost you substantially less over the year.
Don't forget to check what's actually covered under each plan before finalizing your decision. The what's covered hub is a good reference for understanding which services, medications, and procedures most plans include—and which ones vary significantly.
If you're approaching Medicare age or evaluating Medicare options alongside employer coverage, this worksheet applies to employer-sponsored plans only. For Medicare-specific cost questions, see before you enroll in Medicare: questions to ask about each part.
Common Mistakes This Worksheet Helps You Avoid
I want to close with a quick rundown of the errors I see most often during open enrollment—because knowing what can go wrong is half the battle.
- Ignoring the out-of-pocket maximum. This is the most the plan will ever make you pay in a year (outside of premiums). If you have a serious illness or injury, this number becomes your real cost ceiling. Always compare it.
- Forgetting about dental and vision. These are almost always separate plans with separate premiums. Budget for them independently.
- Assuming in-network providers stay in-network. Networks change every year. Confirm your doctors, hospital, and specialists are still covered before you re-enroll in the same plan.
- Missing the employer's HSA seed contribution. Many employers deposit money into your HSA at the start of the year. That's free money—and it should factor into your comparison.
- Estimating drug costs without checking the formulary. A formulary is the list of drugs your plan covers and at what tier (which determines your cost). If you take a brand-name medication, always look it up before enrolling.
Use the open enrollment hub as your home base throughout the process—it covers timing, deadlines, and all the decisions you need to make before the window closes.
All claims in this article are backed by peer-reviewed research. We follow strict editorial guidelines to ensure accuracy and reliability. Sources available on request from our editorial team.
