List price, net price, coupon price — which one am I actually paying, and how do I model 12 months?

I have now seen four different prices for the same product quoted as though each were the real one: a list price in the region of $1,300 a month, a "net price" figure someone cited from an industry report that was less than half of that, a manufacturer cash price around $500, and a copay card claiming $25.

These cannot all be the price. I assume they are prices to different parties at different points in the chain, and that the one I pay depends on facts about my own plan that I have not worked out yet.

Second question, and the one I actually need for budgeting: how do I model a full twelve months including titration? Every calculator I have found assumes the maintenance dose from day one, which cannot be right — the first four months are at lower doses, so the drug quantity is much lower, but the monthly price seems to be flat regardless of dose. I would like to do this properly for both a semaglutide and a tirzepatide schedule.

Extending the model in the direction people actually need it: what happens in year two, because a twelve-month model implies the course ends and for most people it does not.

The withdrawal trials are unambiguous that stopping reverses the effect. After a 20-week run-in, participants switched to placebo regained a substantial share of lost weight over the following year while those continuing kept losing [1], and the tirzepatide withdrawal trial reproduced the pattern [2]. Longer-duration data show maintained loss with continued treatment out to two years [3]. So the honest financial model is not a twelve-month course, it is an indefinite one, and the correct question at the outset is not "can I afford a year" but "what is my sustainable annual run rate".

Three things that changes:

• Year two has no titration. Every month is a maintenance month, so on per-milligram pricing year two costs more drug than year one: 124.8 mg against 100.2 mg for semaglutide, a 24.6% increase. On flat monthly pricing it costs the same. Model whichever applies to you.
• Reauthorisation risk. Coverage frequently requires a documented response, commonly at least 5% weight loss, to continue. So the year-two budget has a branch in it: continued coverage, or a sudden move to the cash row of the table above. Ask what your plan's reauthorisation criterion is before month twelve, and make sure on-treatment weights are being recorded, because failing reauthorisation for absent documentation rather than absent response is a common and entirely avoidable outcome.
• Maintenance dose may be lower than maximum. Several people stabilise below the maximum, which lowers the run rate. Worth modelling as a range rather than a point.

A five-year run rate at any of those monthly numbers is a large amount of money, and that arithmetic — rather than a first-month promotion — is the one that should drive the choice of route and the effort put into coverage.

Practical notes on getting the number that actually applies to you, since the accepted answer explains the categories but not how to extract your own figure.

1. Use the plan's price-transparency tool, not the pharmacy counter. Most plans now expose a member cost-estimator that will quote your out-of-pocket for a specific product, strength and pharmacy. That figure incorporates your deductible status, which no one else can see. Run it for the specific presentation and quantity your prescription will be written for; a different strength can sit on a different tier.
2. Ask the pharmacy for the cash price separately. Occasionally, with a high deductible, the cash price is lower than the insured price. Pharmacies will tell you if asked directly, and in the US pharmacists may no longer be contractually gagged from doing so. Note that a cash purchase generally does not count toward your deductible, which matters if you expect other spending.
3. Check the quantity the prescription is written for. A 28-day supply against a 30-day supply on a weekly injection changes the annual number of fills from 13 to 12, which is a whole month of cost. Copays are per fill, so fill frequency is a real lever.
4. Read the card's fine print for the annual maximum and the expiry. Both are usually stated. Multiply the monthly copay by twelve and check it against the annual maximum; if the maximum is lower, you know in advance which month the price changes.
5. Re-run everything in January. Deductibles reset, formularies change at plan-year boundaries, and a product can move tier or fall off entirely. Budget the first quarter separately from the rest of the year, because that is where the deductible sits.

Doing those five things gives you an actual figure rather than a range, and it takes about an hour. It is also the only way to know which row of the accepted answer's table you are in, which turns out to be the variable with the largest effect on total cost of anything discussed in this topic.