PTCE - Order Entry and Processing (22.5% of the exam) - Section 4.3

Interpret lot numbers, expiration dates, and National Drug Code (NDC) numbers on medication packaging. (Calculation-based.)

Interpret the three-segment structure of an NDC number (labeller, product, and package codes) and locate lot numbers and expiration dates on drug packaging. Apply this information to verify product identity, manage stock rotation, and complete accurate dispensing records.

NDC numberLot numberExpiration dateDrug labelling

Practice question for this objective

Free sampleOrder Entry and Processingeasy

While verifying stock, a technician compares two vials of the same medicine. Both share the identical 10-digit NDC but carry different lot numbers and different expiration dates. What does this combination of matching NDC with differing lot numbers most accurately indicate?

AThey are different strengths of the same medicine.
BThey are the same product from different manufacturing batches. Correct
CThey are products from two different manufacturers.
DThey are the same batch packaged in two different container sizes.

An identical NDC with differing lot numbers identifies the same product produced in separate manufacturing batches. The NDC encodes labeller, product, and package size, whereas the lot number tracks a discrete production batch, so matching NDCs that differ only by lot are the same product from different batches.

Why A is wrong: A change in strength changes the product segment of the NDC; because the NDCs match exactly, the strength is the same, so this is wrong.

Why B is correct: The NDC identifies the labeller, product, and package size, while the lot number identifies a specific production batch, so a shared NDC with differing lots means the same product made in separate batches.

Why C is wrong: The first segment of the NDC identifies the labeller, so an identical NDC rules out different manufacturers despite the tempting difference in lot numbers.

Why D is wrong: Package size is encoded in the NDC and a single batch carries one lot number, so identical NDCs with different lots cannot represent one batch in two package sizes.

See more PTCE practice questions, answers explained.

Exam traps in Order Entry and Processing

Answers that look right on this material and are not. Each one is a distractor from a different question in the PTCE bank for this domain.

The manufacturing plant, the lot number, and the expiration date
Why it is wrong: Tempting because all three appear on packaging, but the lot number and expiry are separate label elements and are never encoded within the NDC segments.
The bottles must contain different strengths of the drug
Why it is wrong: Tempting if one forgets that strength is part of the product segment, but differing strengths would change the NDC, which here is identical.
Bottle two, expiring 02/2027
Why it is wrong: This is tempting if one assumes the newer-looking later date should move first, but placing the later expiry at the front risks the earlier bottle expiring unused.

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