Open Enrollment Is Not a Vibes Exercise
Every fall, HR drops a benefits portal in front of you with two or three plan options, a PDF nobody reads, and a deadline in nine days. Most people glance at the monthly premium, feel a flash of anxiety about the word “deductible,” and pick the PPO because “better coverage” sounds like the safe answer. Then they never run the actual numbers again until next October.
That instinct is backwards. The plan that costs you less depends on comparing what each plan costs you in a good year, a bad year, and everything in between, not on which one has a smaller number on the paycheck stub. Most people never do that comparison. They compare monthly premiums and call it a decision.
Here’s how to actually run it.
The Four Numbers That Decide Everything
Every health plan, no matter how many pages the summary of benefits runs, reduces to four numbers:
- Annual premium: what comes out of your paycheck no matter what happens to your health this year
- Deductible: what you pay before insurance starts covering a percentage of costs
- Coinsurance: the percentage split between you and the insurer after you hit the deductible (a PPO’s “80/20 after deductible” means you pay 20%)
- Out-of-pocket maximum: the hard ceiling on what you pay in a year, premiums excluded
That’s it. Copays, networks, and prescription tiers matter too, but these four numbers let you build a real comparison in about ten minutes. Pull them from your own plan documents. Every plan is different, so what follows uses example numbers to show the method: plug in your actual plan’s figures before you trust the conclusion.
Guaranteed Savings vs. Possible Risk
Here’s the distinction that gets skipped every single open enrollment season: the premium difference between two plans is a guaranteed outcome. The deductible difference is a risk, not a cost.
If the PPO costs $200 more per month than the HDHP, you will pay that $2,400 a year regardless of whether you see a doctor once or twelve times. That money is gone the moment you enroll.
The deductible, by contrast, is money you might pay. If you have a boring, checkup-only year, a high deductible costs you nothing beyond what you’d have paid anyway for basic care. You’re paying a known amount today (the premium gap) to avoid an uncertain amount tomorrow (the deductible exposure). That’s the actual trade you’re making, and it’s worth stating plainly instead of feeling your way through it.
The HSA Multiplier People Leave Out of the Math
Here’s the number most people forget to put on the HDHP side of the ledger: only an HDHP makes you eligible for a Health Savings Account. A PPO, no matter how good, never qualifies.
Three things stack on top of that eligibility:
- Employer HSA contributions. A lot of employers who offer an HDHP option seed your HSA with a few hundred to over a thousand dollars a year, free, whether you use it or not. That money offsets your HDHP costs directly.
- Triple tax treatment. HSA contributions go in pre-tax, grow tax-free, and come out tax-free for qualified medical expenses. No other account in the tax code does all three. A dollar that lands in your HSA is worth more than a dollar of salary, because the salary dollar gets taxed on the way in and, if invested outside a retirement account, taxed again on its growth.
- It’s yours forever. Unlike an FSA, HSA money doesn’t vanish at year end. It’s still there, still invested, still growing, whether you spend it on medical bills or leave it for decades.
Skip an HDHP and you skip all three of these, permanently, for that plan year. That’s a real cost of choosing the PPO that never shows up on the enrollment portal’s comparison chart.
The HSA has its own annual contribution limit and its own minimum-deductible threshold that qualifies a plan as an HDHP in the first place. Both are set by the IRS and adjusted most years, so check the current figures on IRS.gov or your plan’s summary before you build your own numbers. Don’t treat any number you read on a blog post as this year’s rule.
Three Years, Same Person, Two Plans
Numbers beat vibes, so here’s a worked comparison. These are example plan parameters, not any real employer’s actual plan: use the shape of the math, then swap in your own figures.
PPO: $2,400 annual premium, $800 deductible, 20% coinsurance after the deductible, $3,500 out-of-pocket maximum.
HDHP: $1,200 annual premium, $2,500 deductible, 10% coinsurance after the deductible, $5,000 out-of-pocket maximum, plus a $750 employer HSA contribution.
Same person, three different years:
| Year | Medical charges | PPO total cost | HDHP total cost (net of employer HSA) | HDHP saves |
|---|---|---|---|---|
| Healthy | $300 (checkup, a couple prescriptions) | $2,700 | $750 | $1,950 |
| Moderate | $4,000 (ER visit, imaging, minor procedure) | $3,840 | $3,100 | $740 |
| Bad | $30,000 (surgery) | $5,900 | $5,450 | $450 |
Read the pattern: the HDHP wins in all three years in this example, but the margin shrinks every time the year gets worse. That’s the honest shape of this decision. The premium gap ($1,200 a year, guaranteed) does most of the work in a healthy year. In a bad year, both plans cap out near their out-of-pocket maximum plus premium, and the employer HSA contribution is what tips the scale.
Pull the employer contribution out of the bad-year math and the picture flips: the HDHP’s premium plus out-of-pocket max comes to $6,200 against the PPO’s $5,900. Without that $750 landing in your HSA, the HDHP is the worse deal in a bad year. That single number is doing more work in this decision than most people realize when they’re skimming a benefits PDF at 11pm the night before the deadline.
Weight those three years by rough odds (say 70% healthy, 20% moderate, 10% bad, adjust to your own health history) and the expected annual cost comes out to about $3,248 for the PPO and $1,690 for the HDHP in this example: roughly $1,558 a year in favor of the HDHP. Run your own weights. The method matters more than my made-up probabilities.
Your Downside Is Bounded, and You Can Calculate the Bound
The fear driving most PPO picks is some version of “what if something bad happens and the HDHP wrecks me.” That fear is real but overstated, because the out-of-pocket maximum is a hard number, not a guess. Add the annual premium to the out-of-pocket maximum and you have the single worst dollar amount that plan can cost you in a year. That’s the entire calculation.
In the example above, the HDHP’s absolute worst case is $6,200 before the employer contribution, $5,450 after it. The PPO’s worst case is $5,900. Neither number is infinite, neither is a mystery, and both were sitting in the summary of benefits the whole time. Do this arithmetic for your actual plans before enrollment closes. It takes five minutes and it replaces a vague fear with two comparable numbers.
When the PPO Actually Wins
None of this means HDHPs win by default. A few situations flip the math for real:
- You already know this will be an expensive year. Scheduled surgery, a planned pregnancy, a diagnosis you’re actively treating. If you already know you’ll blow past both deductibles, run the worst-case numbers for your specific plans instead of assuming the pattern above holds. Some PPOs have a meaningfully lower out-of-pocket max than their paired HDHP, in which case the PPO wins even in the expensive-year math.
- You have an ongoing specialist relationship. A therapist, a fertility clinic, a physical therapist you see weekly. If the PPO’s copay structure charges a flat $30 per visit instead of coinsurance percentage, frequent care can cost less under a PPO than under an HDHP’s percentage-based cost sharing, even before the deductible is met.
- You’re on expensive maintenance medication. A specialty drug with a $600 monthly list price behaves very differently under a plan with flat copay tiers than under one where you’re paying full coinsurance until you hit the deductible.
- Your spouse has their own employer plan. If one of you can get HDHP-qualified individual coverage while the other carries better dependent coverage through a separate employer, splitting coverage sometimes beats putting the whole family on one plan. Model both configurations.
Check the Network and Formulary Before You Trust Any of This
One more thing that can override every number above: the provider network and the drug formulary aren’t always identical between a PPO and an HDHP offered by the same employer, even when the underlying insurer is the same. Your current doctor being in-network on the PPO doesn’t guarantee they’re in-network on the HDHP tier, and a maintenance drug you take could sit on a different formulary tier with a different price. Check both before you enroll. A perfect cost comparison built on the wrong network is still wrong.
The Family Deductible Trap
If you’re covering a spouse or kids, read the HDHP’s deductible structure closely, because there are two very different designs hiding behind the same word.
Aggregate deductible: the family has one combined deductible (say $6,000), and no individual’s expenses count toward coinsurance until the whole family’s combined spending clears that number. One kid’s ER visit doesn’t unlock coverage on its own; the family total has to get there first.
Embedded deductible: each family member also has an individual deductible embedded inside the family number (say $3,000 per person, $6,000 family cap). Once any one person’s costs hit their individual embedded amount, that person’s coverage kicks in, even if the family total hasn’t been reached.
These produce very different real-world outcomes for a family where one person has most of the medical costs in a given year. An embedded structure protects that person sooner. An aggregate structure can leave everyone paying full price out of pocket for months while unrelated family expenses slowly add up toward the shared number. This detail is buried in the summary of benefits, not the enrollment portal’s headline comparison, so ask HR directly which structure your HDHP uses before you assume the smaller printed number tells the whole story.
Run Your Own Numbers This Week
The PPO isn’t wrong. It’s the right call for people with predictable, ongoing, expensive care, a mismatched network on the HDHP side, or a spouse’s plan that changes the equation. But “better coverage” as a feeling isn’t a comparison, and most people who pick the PPO have never written down what their worst-case year actually costs on either plan.
Pull your own plan documents, find your four numbers, run the three-scenario table, and check the network before the enrollment deadline closes it out for another year. The math takes ten minutes. Guessing costs you the difference every single year you don’t check.
