Interpreting Prescription Orders (Rx)

Sig Codes   |   Expiration Dates   |  Refills   |   Generic Drugs  |   D.E.A.

The prescription information on this site follows Federal guidelines and may not reflect tighter laws in individual states. The Federal requirements for pharmacy technicians are what the PTCB and ExCPT exams will ask about.

Sig Codes - Rx Abbreviations

The lingo "sig" refers to a string of
Prescription Abbreviations
found on a drug order.

When the sig is properly decoded, it becomes the directions for the preparation and use of the medication.

This is important because it tells pharmacy technicians how to dispense it. The sig is also printed on the container the prescription is dispensed in, but, translated into regular words for the patient to read.

Besides decoding a prescription's sig, there are several other concerns. There are refill limits, DEA laws, PPPA requirements, patient requests and many other considerations. Pharmacy technicians must know with certainty how to decode prescription orders.

Click on these links for:

Sig Code List / Abbreviations

Dosage Forms / Routes of Administration

Roman Numerals in Pharmacy

Prescription order expiration dates

A prescription order must be dated, and it has an appropriate expiration date based on the type of drug ordered. If it's not filled in time, the script expires.

DEA Sch II No Expiration
DEA Sch III thru V 6 Months
Legend Drugs 12 Months


If refills are allowed by the prescriber, it will be noted on the prescription. However, there are boundaries and limitations. These are the guidelines:

DEA Schedule III thru V up to 5, but only 5 times*
Legend Drugs up to 12 Months worth

*If a patient has a Sch 3-5 prescription with 5 refills of 100, but can only afford 50 at a time, they will only get 250 total. (not 500) Period. Each time a refill is redeemed, that refill is then voided. So, if you are authorized a refill of 100, but only get 50, you then forfeit the other 50.

Generic Substitutions

Generic drug substitutions
may not be used unless the prescriber has authorized it. Generic substitutions may only be used if the prescriber has requested or authorized them.

DEA Controlled Drug Prescriptions

Must contain at least :
  • Date of prescription issue
  • Patient's name and address
  • Practitioner's name, address, and phone number
  • Drug name
  • Drug strength
  • Dosage form and instructions
  • Exact quantity prescribed
  • Complete directions for use
  • Number of refills authorized
  • Have a valid DEA Number

Schedule II drug prescriptions also:

→ Must be manually signed by the practitioner. No exceptions.

→ May not be Faxed or Called in, except for a valid emergency.

→ May not have any refills.

Pediatric Dosage Calculations

Pediatric Dosage Calculation methods should be memorized to prepare for the pharmacy technician exam. However, in the field most prescribers will use a ratio to body weight formula for more accuracy. Pharmacy technicians will be better equipped to package the correct dosage with this more straight-forward method.

Where would you like to go now?

Common Prescription Abbreviations Page

Roman Numerals on Prescriptions

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