What does “written order prior to delivery” mean?
A written order prior to delivery, or WOPD, is a signed order the supplier must have in hand before it delivers certain items. The Medicare policy for TENS units says that for items that require one, “the supplier must have received a signed SWO before the DMEPOS item is delivered to a beneficiary.” SWO means Standard Written Order. DMEPOS means durable medical equipment, prosthetics, orthotics and supplies.
This post explains the Medicare wording as of the LCD revision effective January 1, 2024. It is general information. Your clinician and your plan decide what applies to you.
What is the difference between an SWO and a WOPD?
They are related. Every claim for a TENS item needs a Standard Written Order. Only some items also need it before delivery. The LCD (L33802) says the SWO “must be communicated to the supplier before a claim is submitted.” For base items that require a WOPD, the order must come before the item is delivered.
| Term | Plain meaning | What Medicare says |
|---|---|---|
| SWO (Standard Written Order) | The signed order for the item | Must reach the supplier before a claim is submitted. Without a completed SWO, the claim is denied as not reasonable and necessary. |
| WOPD (Written Order Prior to Delivery) | An SWO received before delivery | If a supplier delivers an item that requires a WOPD without first receiving one, the claim is denied as not reasonable and necessary. |
| Face-to-face encounter | A visit with the practitioner before certain orders | Policy article A52520 says Final Rule 1713 requires one, with a WOPD, for specified HCPCS codes. |
The article says the face-to-face rule and WOPD apply to “specified HCPCS codes.” If you need to know whether a given item is on it, ask your supplier or check the current CMS policy.
Why does the timing matter so much?
Because a late order cannot repair the problem. Policy article A52520 says: “If the WOPD is not obtained prior to delivery, payment will not be made for that item even if a WOPD is subsequently obtained by the supplier.”
The LCD adds a rule for accessories. For a base item that requires a WOPD and also has separately billed options, accessories or supplies, the supplier must have a WOPD for the base item that lists the base item. It may list the associated items too. If the supplier bills those separately without a completed, signed WOPD of the base item before delivery, the claims “shall be denied as not reasonable and necessary.”
Who can give the order?
The LCD says: “The practitioner ordering the Transcutaneous Electrical Nerve Stimulators (TENS) unit and related supplies must be the treating practitioner for the disease or condition justifying the need for the TENS unit.” So the order should come from the clinician who treats the pain, not a third party.
Related terms you may see:
- Durable medical equipment is equipment meant for repeated use at home.
- A face-to-face encounter is a visit in which a practitioner evaluates the patient before ordering certain equipment.
- Medical necessity means a payer agrees the item is reasonable and needed.
Does a TENS unit need a prescription outside Medicare?
It depends on the unit. Under 21 CFR 882.5890, a TENS unit is a device “to treat pain.” A prescription device is one “to be sold only to or on the prescription or other order of such practitioner” (21 CFR 801.109), and its label carries the statement “Rx only” or a similar caution. Ask your clinician which route applies to your unit. Cleveland Clinic says you can get a prescription from a provider, or buy an over-the-counter unit at a pharmacy.
For other plans, check with your plan. University of Iowa Health Care says TENS units “are not routinely covered by insurance, but all companies have different policies.”
What about the Certificate of Medical Necessity?
Policy article A52520 says: “Providers and suppliers no longer need to submit Certificate of Medical Necessity (CMN) for services rendered on or after January 1, 2023.” It also says “A CMN is not needed for a TENS rental.” Older forms (CMS Form 848 for TENS) apply only to earlier dates of service.
What should you ask your clinician and supplier?
These questions help you check the paperwork before a unit arrives.
- Has my clinician signed a Standard Written Order for the TENS unit and supplies?
- Did the supplier receive it before the unit was delivered?
- Does my diagnosis meet the Medicare criteria? Our post on chronic low back pain and Medicare shows one case that is denied.
- What does my plan, if not Original Medicare, require?
Clinics can find a documentation list in our TENS referral checklist for clinics. The full guide to how to get a TENS unit covers the steps in order.
Next step
Ask your clinician to confirm the order is written and signed before any unit is delivered. Clinics can use the preauthorization form. Patients can call Analgesic Healthcare at (800) 749-1188 or use contact.
Questions people ask
What is a written order prior to delivery?
It is a signed Standard Written Order that the supplier receives before it delivers an item that requires one. The Medicare LCD for TENS says that if a supplier delivers such an item without first receiving a WOPD, the claim shall be denied as not reasonable and necessary.
Can the order arrive after the TENS unit is delivered?
For an item that requires a WOPD, no. Medicare policy article A52520 says that if the WOPD is not obtained prior to delivery, payment will not be made for that item even if a WOPD is subsequently obtained by the supplier.
Does a TENS unit need a prescription?
Medicare requires a Standard Written Order from the treating practitioner before a claim is submitted. Under FDA rules, a prescription device is sold only to or on the prescription or other order of a practitioner. Over-the-counter units follow a different route.
Does Medicare still use a Certificate of Medical Necessity for TENS?
Not for services on or after January 1, 2023. Policy article A52520 says providers and suppliers no longer need to submit CMNs or DIFs with claims for dates of service on or after that date.
Terms on this page
Sources
- CMS Medicare Coverage Database: LCD Transcutaneous Electrical Nerve Stimulators (TENS) (L33802)
- CMS Medicare Coverage Database: Article Transcutaneous Electrical Nerve Stimulators (TENS) - Policy Article (A52520)
- eCFR: 21 CFR 882.5890 Transcutaneous electrical nerve stimulator for pain relief
- eCFR: 21 CFR 801.109 Prescription devices
- Cleveland Clinic: Transcutaneous Electrical Nerve Stimulation (TENS)
Checked against the sources above on October 26, 2026. Coverage rules change, so check the linked page or your plan before you act.
This page gives general information, not medical advice. Talk with your doctor or physical therapist about your own care, and follow your clinician's and your device's instructions. In an emergency, call 911.
