Epic Willow is the pharmacy module within Epic’s electronic health record (EHR) system. It handles everything pharmacists and pharmacy technicians do digitally, from verifying medication orders and managing drug inventory to processing prescriptions and checking for safety alerts. Willow is not a standalone product. It’s one piece of Epic’s broader software suite, sitting alongside modules for clinical care, billing, oncology, and other hospital functions.
The Three Parts of Willow
Willow is split into distinct products based on pharmacy setting:
- Willow Inpatient handles pharmacy operations inside the hospital. When a doctor orders a medication for a patient who’s been admitted, that order flows through Willow Inpatient for pharmacist verification before the drug is prepared and administered. Even medication orders placed in outpatient clinics that need to be given on-site still route through the inpatient module for verification.
- Willow Ambulatory covers outpatient pharmacy work. It receives electronic prescriptions from physicians using any Epic application, processes refill requests that patients submit through the MyChart patient portal, and accepts external electronic prescriptions through Surescripts, the national e-prescribing network. If your doctor sends a prescription to your pharmacy electronically, Willow Ambulatory is the system on the receiving end at Epic-based pharmacies.
- Willow Inventory is Epic’s medication inventory management system. It tracks drug stock levels and works alongside the other two modules to keep pharmacies supplied.
How Willow Fits Into Patient Safety
One of Willow’s most important roles is supporting barcode medication administration, often called BCMA. This is the system where nurses scan both the patient’s wristband and the medication’s barcode before giving a drug. The goal is to confirm the “five rights”: right patient, right medicine, right dose, right time, and right route. When the system detects a mismatch, it fires an alert. Wrong-patient alerts are especially effective. In one published study, scanning caught wrong-patient wristband errors 82% of the time, prompting nurses to recheck before proceeding.
These checks run continuously. Every time a nurse administers a dose in a hospital using Epic, the barcode system cross-references the scanned information against the active medication orders in the patient’s chart. If a medication has been discontinued, if the dose doesn’t match, or if the wrong patient’s wristband was scanned, the system flags it immediately.
Specialty Pharmacy Features
Willow includes a specialty pharmacy component designed for high-cost, complex medications that require extra coordination. This module handles several workflows that go well beyond simple prescription filling.
Prior authorization management is built in. When a prescribed medication requires insurer approval, pharmacy staff can take ownership of that process directly within Epic, working authorization requests from their in-basket messages rather than juggling phone calls and fax machines separately. The system also supports pharmacy benefit verification, which matters because a patient’s prescription drug coverage often differs from their medical insurance plan. Staff can check real-time prescription benefit information to see what a medication will cost the patient before it’s dispensed.
Medication adherence tracking estimates how consistently a patient has been filling and presumably taking their prescriptions, assigning a percentage value based on fill history. Pharmacists can also document clinical interventions (called i-Vents within Epic) to track the work they do beyond dispensing, such as counseling patients or resolving drug interactions, along with how long those activities take. For controlled substances, Willow connects to state Prescription Drug Monitoring Programs so pharmacists and providers can review a patient’s controlled substance history directly from the patient’s chart.
Integration With Other Epic Modules
Willow doesn’t operate in isolation. It connects to the clinical modules that doctors and nurses use, so medication orders flow seamlessly from the prescriber into the pharmacy queue. In oncology settings, for example, pharmacists working with chemotherapy and infusion protocols use Epic’s Beacon module for treatment planning, but they need Willow training as a prerequisite because the actual drug verification and dispensing happens through Willow.
The system also plays a role in federal drug pricing programs. Hospitals that qualify for the 340B program, which provides significantly discounted medications to eligible healthcare organizations, use Willow alongside specialized compliance software to determine whether a patient and prescription qualify for 340B pricing. The logic checks the prescriber, the location where the prescription originated, when the patient was last seen at a qualifying facility, and a range of other rules before applying the discounted price.
Training Requirements for Pharmacy Staff
Using Willow requires formal training, and the requirements vary by role. Outpatient pharmacists and technicians both complete a four-hour classroom session for Willow Ambulatory, plus an online prerequisite course. Completing both is mandatory to receive and keep Epic pharmacy access.
Inpatient pharmacists also attend a four-hour class with an online prerequisite. Inpatient pharmacy technicians have a shorter path at two hours with no prerequisite. Specialty pharmacy staff take a separate 2.5-hour course with its own online component. Staff who handle 340B compliance auditing need the broadest training: they must complete the Willow Ambulatory, Willow Inpatient pharmacy technician, and Willow Inventory courses.
These aren’t optional continuing education credits. At institutions running Epic, completing the assigned Willow training is a hard requirement for getting system access. If you skip the classroom session, your pharmacy access gets revoked.
Who Uses Willow
Willow is used by pharmacists, pharmacy technicians, compliance coordinators, and in some workflows by nurses and prescribers who interact with medication orders. Because Epic dominates the U.S. hospital EHR market, Willow is the pharmacy system at many of the country’s largest health systems and academic medical centers. If you’re a pharmacy professional interviewing at a hospital that runs Epic, Willow experience or certification is often listed as a preferred or required qualification. If you’re a patient at an Epic hospital, Willow is the system working behind the scenes every time your medications are ordered, checked, and dispensed.