How to read a RxTrueCost drug page

What NADAC actually is

Every drug page on this site starts with a NADAC number. NADAC stands for National Average Drug Acquisition Cost. It comes from CMS, which surveys pharmacies about what they pay wholesalers for drugs. It's published weekly.

NADAC is not a retail price. It's not what you pay at the counter. It's an estimate of pharmacy acquisition cost, meaning what the pharmacy itself pays to get the drug in the door. Your out-of-pocket cost depends on your insurance, your pharmacy's contract with a pharmacy benefit manager, dispensing fees, and other things this site does not track.

Use NADAC to understand the cost floor a pharmacy is working from. Don't use it to predict your copay.

Pricing unit: EA, ML, GM

Every NADAC price is tied to a unit. You'll usually see one of three:

• EA (each) for things like tablets and capsules, priced per pill
• ML (milliliter) for liquids
• GM (gram) for creams, ointments, and powders

The pricing unit matters because it's the only way the number makes sense. A NADAC of $0.85 per EA for a tablet is not comparable to $0.85 per ML for a liquid. They're different products measured different ways. When you compare two drug pages, check that the units match before you compare the numbers.

Effective date

Each price on the page has an effective date. That's the date CMS says the price applies from, not the date we pulled the data. NADAC updates weekly, so the number you see is the most recent one as of that file.

An effective date does not tell you how long a price will last. Prices can hold steady for months or shift the next week. The date just anchors this specific number in time.

The member NDC table

A single drug name can cover many NDCs (National Drug Codes), each tied to a specific manufacturer, package size, or formulation. The member NDC table lists the NDCs that roll up into the price shown on the page.

This table lets you see the ingredients behind the summary number. If a price looks like it moved, checking the NDC table can show whether a new manufacturer's NDC entered the data or dropped out. That kind of change can shift an average without any single product's price actually changing.

What the table doesn't do is tell you which NDC your pharmacy stocks. That's between you and your pharmacy.

The history chart

The history chart plots NADAC per unit over time. It's built from past weekly CMS files, so it shows the trend as CMS reported it, not a smoothed or adjusted version.

Read it for direction and rough stability. A flat line means the reported price hasn't moved in the data. A step change means something shifted, a new survey response, a manufacturer change, a market event.

Don't read small week-to-week wiggles as meaningful on their own. NADAC is a survey-based average, and averages move for reasons that have nothing to do with your local pharmacy's actual cost that week.

The 4-week change

This figure compares the current NADAC to the value from four weeks earlier. It's a plain difference, not a forecast and not a trend line by itself.

A positive 4-week change means the reported acquisition cost went up over that window. A negative one means it went down. Neither tells you why. Price changes in NADAC can come from real market movement, from a shift in which NDCs are included in the average, or from data reporting changes at the pharmacy level.

Treat the 4-week change as a signal to look closer, not a conclusion. Pair it with the history chart and the NDC table before drawing any inference about a trend.

What none of this tells you

No number on this site tells you what you will pay, what your insurance will charge, or whether a drug is a good clinical choice for you. This site tracks acquisition cost data only. For anything about coverage, cost-sharing, or treatment decisions, talk to your pharmacist, your insurer, or your prescriber.