In Illinois, how long a prescription is good for depends on what’s in the bottle. A prescription for a non-controlled medication stays valid for up to 15 months from the date it was written. Schedule III, IV, and V controlled substances are good for 6 months. Schedule II drugs, which include most opioid painkillers and stimulants like amphetamine-based ADHD medications, expire after just 90 days and carry no refills at all.
Non-Controlled Medications: 15 Months
Most prescriptions fall into this category: antibiotics, blood pressure drugs, cholesterol medications, antidepressants that aren’t controlled, and similar therapies. The Illinois Pharmacy Practice Act sets the outside limit at 15 months from the date your provider wrote the prescription.1Illinois General Assembly. Illinois Compiled Statutes 225 ILCS 85 – Pharmacy Practice Act The Illinois Administrative Code says the same thing from the other direction: no prescription may be dispensed after 15 months from the original issue date.2Illinois General Assembly. 68 Illinois Administrative Code 1330
Your prescriber decides how many refills to authorize, but every refill has to happen inside that 15-month window. Whichever runs out first — the refills or the time — ends the prescription. Once it’s dead, you need a new one.
One thing that surprises people at the counter: your insurance plan may impose shorter limits than the law does. Many pharmacy benefit managers cap retail fills at a 30-day supply for chronic medications even when your doctor wrote for 90 days. That isn’t a legal restriction. It’s a coverage decision, often meant to push patients toward mail-order pharmacies for 90-day fills. If the pharmacy tells you they can only give you 30 days, ask whether the limit is on the prescription itself or on your insurance.
Schedule II Controlled Substances: 90 Days, No Refills
Schedule II covers many opioid painkillers, amphetamine-based ADHD stimulants, and other high-risk drugs. In Illinois, a Schedule II prescription is valid for up to 90 days from the date it was issued, cannot be refilled, and is capped at a 30-day supply per prescription.3Justia Law. Illinois Compiled Statutes 720 ILCS 570 – Illinois Controlled Substances Act – Article III
To spare patients a monthly office visit, Illinois lets physicians write three separate prescriptions at one appointment, each for a 30-day supply, for up to 90 days of medication total. The second and third prescriptions must carry a “do not fill before” date so the pharmacy knows when each one becomes dispensable, and the physician has to document the medical need for the arrangement in your chart.3Justia Law. Illinois Compiled Statutes 720 ILCS 570 – Illinois Controlled Substances Act – Article III Federal regulation mirrors this, requiring each individual prescription to meet independent clinical standards.4eCFR. 21 CFR 1306.12 – Refilling Prescriptions; Issuance of Multiple Prescriptions
The no-refill rule is absolute. There are no emergency exceptions and no pharmacist workarounds. If the prescription has expired or you’ve already filled it, you need a brand-new one from your provider.
Schedule III, IV, and V Controlled Substances: 6 Months, Up to 5 Refills
This tier includes drugs like testosterone, certain sleep aids, some anti-anxiety medications, and low-dose codeine preparations. The prescription is valid for six months, and within those six months it can be refilled up to five times.3Justia Law. Illinois Compiled Statutes 720 ILCS 570 – Illinois Controlled Substances Act – Article III That refill cap matches the federal DEA standard.5eCFR. 21 CFR 1306.22
Whichever limit hits first controls. If your prescriber authorized five refills but six months pass before you use them all, the leftover refills are gone. If you burn through five refills in three months, the prescription is finished even though the six-month window is still open. Either way, you need a fresh prescription to continue.
When You Can’t Reach Your Prescriber
Running out of a maintenance medication over a weekend or a holiday is a common problem. For non-controlled drugs only, Illinois law lets a pharmacist dispense up to a 30-day emergency supply if the prescriber can’t be reached for authorization. Several conditions apply:6Illinois General Assembly. Illinois Compiled Statutes 225 ILCS 85/15.3 – Public Act 100-0237
- The pharmacist must judge that interrupting your therapy could cause harm or suffering.
- The same pharmacy must have previously filled a prescription from the same prescriber for the same medication for you.
- The pharmacist has to tell you that future refills need prescriber authorization.
- The pharmacist documents the fill and notifies your prescriber.
Emergency dispensing does not apply to any controlled substance, regardless of schedule. This provision is a safety net, not a workaround for repeated lapses.
Telehealth Prescriptions Follow the Same Deadlines
Through December 31, 2026, the DEA and HHS have extended pandemic-era flexibilities that let DEA-registered practitioners prescribe Schedule II through V controlled substances by audio-video telemedicine without a prior in-person visit. Audio-only phone encounters are also permitted for medications treating opioid use disorder in Schedules III through V.7Gordon Rees Scully Mansukhani. HHS and DEA Extend Telemedicine Flexibilities for Prescribing Controlled Medications Through 2026
The validity periods and refill limits above apply identically to prescriptions issued this way. A Schedule II prescription written after a video visit still expires in 90 days and still cannot be refilled. Telehealth changes how you get the prescription, not how long it lasts.
What to Do When a Prescription Expires
An expired prescription is unworkable. No pharmacy in Illinois can legally fill it. Contact your prescriber’s office. Depending on the medication and how long it’s been since your last visit, your provider may be able to send a new prescription without seeing you, or you may need to come in. For controlled substances, and especially Schedule II drugs, expect a higher likelihood of an office visit before a new prescription goes out.
Quick Reference
- Non-controlled medications: valid up to 15 months from the date issued, with refills allowed as authorized by the prescriber, all within the 15-month window.
- Schedule II controlled substances: valid up to 90 days from the date issued, no refills, maximum 30-day supply per prescription. A physician may write three sequential prescriptions at one visit for up to 90 days total.
- Schedule III, IV, and V controlled substances: valid up to 6 months from the date issued, up to 5 refills within that 6-month period.