How to read an NDC, a lot number and an expiration date
PTCB topic: Lot numbers, expiration dates and NDC numbers
- An NDC has three parts: labeler, product and package code.
- Ten-digit NDCs come as 4-4-2, 5-3-2 or 5-4-1.
- For billing, add one leading zero to make 5-4-2.
- The uniform 12-digit NDC takes effect March 7, 2033.
- Vaccine EXP month/year means good through that month's last day.
Key facts
- The NDC's three segments are the labeler code (assigned by FDA), the product code and the package code.
- Today's 10-digit NDCs come in three configurations: 4-4-2, 5-3-2 and 5-4-1.
- A change in strength, dosage form or active ingredient needs a new product code; a change in package size or type needs only a new package code.
Show all 7 key factsShow fewer
- The HIPAA 11-digit NDC is always 5-4-2; add one leading zero to the short segment.
- FDA's uniform 12-digit NDC (6-4-2) takes effect March 7, 2033, with 3 more years allowed for 10-digit NDCs already on labels.
- A lot number lets the complete manufacturing and distribution history of a batch be traced; vaccine records must include manufacturer and lot number.
- For vaccines, CDC says EXP with only a month and year means usable through the last day of that month; a beyond-use date can shorten, never extend, the expiration date.
Quick check1 question · 2 more at the end
In the NDC 0173-0682-20 printed on a VENTOLIN HFA carton, what does the middle segment, 0682, identify?
Correct answer: D.
An NDC has three segments: labeler code, product code and package code (21 CFR 207.33). The middle segment is the product code, which changes when the drug, its strength, dosage form or similar product details change. In 0173-0682-20, 0173 is the labeler, 0682 is the product and 20 is the package.
A The labeler is the first segment, 0173, which FDA assigns to the firm.
B Package size and type are identified by the last segment, 20.
C The lot number is printed separately on the label; it is not part of the NDC.
D Correct: the middle segment is the product code, which identifies the specific drug, strength and dosage form.
Full lesson
Each part starts with its main idea. Open a part when you want the details.
The short answer: An NDC has three segments: labeler code, product code and package code, in 4-4-2, 5-3-2 or 5-4-1 form. Billing uses an 11-digit 5-4-2 version made by adding a leading zero. A uniform 12-digit NDC starts March 7, 2033. The lot number traces the batch, and CDC says a vaccine's month-and-year expiration runs through that month's last day.
1 How is an NDC built?Every National Drug Code splits into three segments that name the firm, the product and the package. 1 min
Every National Drug Code splits into three segments that name the firm, the product and the package. FDA's rule (21 CFR 207.33) requires a unique NDC for each drug's labeler, product, and package size and type. FDA assigns the labeler code; today only 5-digit labeler codes are being issued.
Take VENTOLIN HFA, NDC 0173-0682-20:
| Segment | Digits | Identifies |
|---|---|---|
| Labeler code | 0173 | The firm |
| Product code | 0682 | Drug, strength, dosage form |
| Package code | 20 | Package size and type (18 g, 200 actuations) |
Current 10-digit NDCs come in three configurations: 4-4-2, 5-3-2 and 5-4-1.
2 What changes the product code versus the package code?A new strength or form changes the product code, while a new package changes only the last segment. 1 min
A new strength or form changes the product code, while a new package changes only the last segment. Under 21 CFR 207.35, some changes need a new product code. They are a change in the name, an active ingredient or its strength, the dosage form, Rx/OTC status or the tablet's appearance. A change only in package size or type gets a new package code.
VENTOLIN HFA shows this: 0173-0682-20 is the 200-actuation canister and 0173-0682-24 is the 60-actuation one. The lot number never appears in the NDC.
3 How do you convert an NDC to the 11-digit billing format?Billing systems use a fixed 5-4-2 layout, so you pad the short segment with a leading zero. 1 min
Billing systems use a fixed 5-4-2 layout, so you pad the short segment with a leading zero. HIPAA transactions use this 11-digit format.
| 10-digit NDC | Short segment | 11-digit (5-4-2) |
|---|---|---|
| 0173-0682-20 (4-4-2) | Labeler | 00173-0682-20 |
| 76204-011-55 (5-3-2) | Product | 76204-0011-55 |
| Any 5-4-1 NDC, package code 3 | Package | Package code becomes 03 |
The zero always goes in front of the short segment.
4 Is the NDC changing to 12 digits?Yes, but not until 2033, so 10-digit NDCs are still current. 1 min
Yes, but not until 2033, so 10-digit NDCs are still current. FDA's final rule of March 5, 2026 adopts one uniform 12-digit, 6-4-2 NDC. It takes effect March 7, 2033. Existing NDCs will then be converted by adding leading zeros, and FDA says it will not object to 10-digit NDCs still on labels during a 3-year transition.
5 What does a lot number tell you?A lot number is the batch's fingerprint, linking the package to its full manufacturing history. 1 min
A lot number is the batch's fingerprint, linking the package to its full manufacturing history. FDA defines it as letters, numbers or symbols from which a batch's complete manufacturing, packing, holding and distribution history can be traced.
That is why recall notices list lots. It is also why federal law requires the vaccine manufacturer and lot number in the record for each covered vaccine given. A vaccine and its diluent each have their own lot number and expiration date.
6 How do you read an expiration date?For vaccines, CDC says a month-and-year date means the product is good through the last day of that month. 1 min
For vaccines, CDC says a month-and-year date means the product is good through the last day of that month. A vaccine labeled 12/2026 is usable through December 31, 2026. If a day is printed, the vaccine is good only through the end of that day.
Some products get an earlier deadline once opened or prepared:
- A beyond-use date (BUD) counts from day 0, the day the vial is punctured, mixed or moved. It can shorten the expiration date but never extend it; use whichever comes first.
- An opened LANTUS vial may be kept for up to 28 days. Opened March 10 (day 0), its last day of use is April 7.
Common mistakes
The traps students fall into most. Read these before you practice.
Watch out: The lot number is printed separately from the NDC, not inside it.
Watch out: Zeros for the 11-digit format go in front of the short segment, not at the end.
Watch out: The 12-digit NDC rule is final but not in force until 2033, so 10-digit NDCs are still current.
Watch out: A vaccine labeled EXP 11/2026 is good through November 30, not November 1.
Watch out: An opened LANTUS vial is discarded after 28 days, not at the printed expiration date.
How to remember it
Say "Who, what, how many" to recall the NDC's three segments in order. They stand for labeler, product and package. For dates, remember "month means the month's last day."
Self-check:
- Which segment changes when a bottle count changes?
- Convert 0173-0682-24 to the 5-4-2 format.
- A vial says EXP 02/2027 and has a BUD of February 10, 2027. Which date controls?
Show answers
- The package code.
- A change only in package size or type gets a new package code.
- The labeler and product codes stay the same.
- 00173-0682-24.
- 0173-0682-24 is a 4-4-2 NDC.
- The short segment is the labeler code (4 digits).
- Add one leading zero in front of it: 00173-0682-24.
- February 10, 2027.
- Even read to the month's last day, EXP 02/2027 ends after February 10.
- A BUD can shorten the expiration date but never extend it.
- Use whichever comes first: February 10.