Hi there!

Welcome back to the RelayEd Pharmacy Tech Toolkit, a practical study newsletter designed to help pharmacy technicians and technician students build confidence one skill at a time.

Each issue breaks down a pharmacy concept you may see on the PTCE or encounter in practice, with clear explanations, worked examples, and quick practice to help reinforce what you learn.

Today’s Theme: Reading an NDC

Imagine you are filling a prescription and find three bottles of the same medication on the shelf.

The drug names look the same.

But one is a different strength.

Another is from a different manufacturer.

And another contains a different package quantity.

This is one reason the National Drug Code, or NDC, matters.

An NDC identifies a specific drug product and package.

For pharmacy technicians, recognizing how an NDC works can help with:

• Selecting the correct product
• Entering prescription information
• Managing inventory
• Checking medication packages
• Identifying products during recalls
• Preventing dispensing errors

Good to know: The FDA will transition to a uniform 12-digit NDC format beginning March 7, 2033.

---

Breaking Down the NDC

An FDA NDC is divided into three segments:

1.Labeler

Identifies the labeler associated with the product, such as a manufacturer, repackager, relabeler, or distributor under whose name the drug is marketed.

2. Product

Identifies the specific drug product.

This helps distinguish characteristics such as the medication's:

• Strength
• Dosage form
• Formulation

3. Package

Identifies the package size or type.

Think:

LABELER – PRODUCT – PACKAGE

---

Order Entry Corner

Currently, FDA-assigned NDCs use a 10-digit format in one of three configurations: 4-4-2, 5-3-2, or 5-4-1.

• For many electronic billing and reimbursement transactions, the 10-digit FDA NDC is converted to the standardized 11-digit HIPAA format: 5-4-2
• Convert a 10-digit NDC to the 11-digit format by adding a leading zero to the segment that is short
• The zero is added to the beginning of that segment, not the end

Consider this fictional NDC:

12345-678-90

You do not need to know what drug this represents for this example.

Instead, identify the three sections.

12345 = Labeler

678 = Product

90 = Package

Quick way to remember it:

Who labels/markets it → What product is it → Which package is it

Try It Yourself

Consider this fictional NDC:

54321-1234-5

Which part identifies the package?

Try it before looking below.

Answer

5

The NDC contains three segments:

54321 | 1234 | 5

• 54321 = Labeler
• 1234 = Product
• 5 = Package

The final segment identifies the package.

Product Selection: Don't Stop at the Drug Name

Suppose the prescription calls for:

Metformin 500 mg tablets

You locate several bottles:

Bottle A: Metformin 500 mg tablets
​Bottle B: Metformin 1000 mg tablets
​Bottle C: Metformin 500 mg extended-release tablets

All three say metformin, but they are not the same product.

The technician must pay attention to the complete product information, including:

Drug + strength + dosage form/formulation

Choosing a product based only on the medication name can result in a dispensing error.

Best match:

If the prescription specifically calls for immediate-release metformin 500 mg tablets, Bottle A is the appropriate match among these choices.

---

What Else Should You Check?

The NDC is useful, but it is not the only information that matters when selecting a product.

Before using a medication package, technicians may need to verify information such as:

• Drug name
• Strength
• Dosage form
• Package size
• Expiration date
• Lot number
• Product integrity

The exact workflow depends on the pharmacy's procedures and applicable laws and regulations.

NDC vs. Lot Number vs. Expiration Date

These numbers are easy to mix up.

NDC

Identifies the drug product and package.

Lot Number

Identifies a particular manufacturing lot or batch.

This can become especially important when identifying medication affected by a recall.

Expiration Date

Indicates the manufacturer's labeled expiration date for the product.

Remember:

NDC = What product and package?

Lot = Which batch?

Expiration = How long is this package labeled for use?

---

Safety Check: Similar Packages

Medication shelves can contain products that look very similar.

Two bottles may have:

• Similar names
• Similar label designs
• The same manufacturer
• Different strengths
• Different dosage forms
• Different NDCs

Never assume that two similar-looking packages contain the same product.

A good verification habit is to compare the prescription or medication order with the actual product being selected.

Top 200 Medication: Levothyroxine

• Generic: Levothyroxine
• Common brand: Synthroid
• Class: Thyroid hormone
• Primary use: Hypothyroidism
• Common strengths:​
  25 mcg, 50 mcg, 75 mcg, 88 mcg, 100 mcg, 112 mcg, 125 mcg, 137 mcg, 150 mcg, and others

What should you know?

Levothyroxine is a narrow therapeutic index drug available in many different strengths, and some are very close to one another.

For example:

Levothyroxine 100 mcg

and

Levothyroxine 112 mcg

are different products even though the numbers look similar.

This makes careful attention to the drug name, strength, dosage form, and NDC especially important during order entry and product selection.

Safety Check

Because levothyroxine comes in numerous strengths, never rely on tablet appearance or package color alone.

Verify the prescribed strength and selected product carefully, and refer any discrepancy or uncertainty to the pharmacist.

From the Marketplace

Pharmacy Technician Calculations + Order Entry Practice Pack

Ready to practice beyond today’s topic? This 23-page study guide + separate 35-question practice packet combines pharmacy calculations with realistic order-entry and error-detection exercises.

Practice includes:

• Days’ supply and quantity calculations
• Sig translation
• Product and strength matching
• ER/IR and dosage-form mismatches
• Refills and prescription discrepancies
• Order-entry error detection
• Worked calculations and detailed answer explanations

A practical way to build both calculation skills and the ability to recognize when something doesn’t look right.

Get the Calculation Pack

One-Minute Knowledge Check

1.Which portion of an NDC identifies the specific drug product?

A. Labeler segment
B. Product segment
C. Package segment
D. Lot number

2. Which identifier distinguishes a particular manufacturing lot or batch of a medication?

A. Lot number
B. Prescription number
C. Days' supply
D. Refill number

3. A prescription calls for Drug X 25 mg tablets. Which product should make you stop and investigate before proceeding?

A. Drug X 25 mg tablets
B. Drug X 50 mg tablets
C. Drug X 25 mg tablets with a matching product description
D. Drug X 25 mg tablets in an appropriate package

Answers below.

---

Liz Fredrickson, PharmD, BCPS Founder, RelayEd liz@relayedllc.com

Always verify medication information using current product labeling, course materials, and workplace policies.

RelayEd provides independent educational resources and is not affiliated with, endorsed by, or sponsored by PTCB.