Written and maintained by CASRAI Editorial Board
Published · Last updated
On this page
Short answer: a letter of medical necessity for diapers is a clinician-signed statement that supports an order for incontinence supplies. Oklahoma Medicaid and Geisinger Health Plan ask for more than a diagnosis: the underlying condition, the product, daily use, duration and quantity. The payer, not the letter, decides coverage.
This page is general information for supply and documentation staff, not medical advice. Coverage rules differ by state, plan and product type, so the plan document that applies to a given member governs.
What the letter is and what it is not
In practice the letter sits beside a prescription or order and records the member’s documented condition and the products ordered. For general background on who writes such letters and what reviewers look for, see the CASRAI guide to the letter of medical necessity, and for a worked layout see the sample letter of medical necessity. For Medicare specifically, see whether Medicare covers incontinence supplies.
A letter alone is not medical necessity. The Oklahoma Health Care Authority (OHCA) states that requests by medical services providers “in and of itself shall not constitute medical necessity” and that OHCA is “the final authority pertaining to all determination of medical necessity” (Incontinence Supplies Guidelines, last reviewed 10/1/2020, effective 10/14/2020).
At the federal level, the Medicaid home health rule at 42 CFR 440.70 requires that medical supplies, equipment and appliances be ordered by a physician or other licensed practitioner and that the beneficiary’s need be reviewed by a physician; it describes supplies as consumable or disposable health care related items required to address an individual medical disability, illness or injury. It leaves the product-level documentation detail to state programs and plans.
What two payer policies ask the letter or order to contain
The table sets two real documents side by side. Each cell comes from the policy named in the column heading, as checked on 2026-11-01.
| Element | Oklahoma Medicaid (OHCA, eff. 10/14/2020) | Geisinger Health Plan MP274 (Medicaid segment) |
|---|---|---|
| Who orders | Signed provider prescription with date of order, ordering practitioner, member name and items (HCPCS code, narrative or brand), or a completed HCA-52 form | Physician prescription; prior authorization by a plan medical director or designee |
| Diagnosis | An underlying condition involving loss of bladder or bowel control; a diagnosis of only urinary incontinence, fecal incontinence or enuresis is not sufficient | Diagnosis of the medical condition causing the incontinence; physician documentation of a type of urinary incontinence or of fecal incontinence |
| Usage and duration | Expected length of need | Number used per day and anticipated duration of need |
| Quantity | Height, weight and type of incontinence to support the size and amount requested | Quantity of items requested; diapers and pull-ups combined are capped at 300 per month unless the Medical Director reviews documentation |
| Other treatments | Tried-and-failed treatments “when indicated”, such as medications, pelvic floor exercises, bedside commode or behavior modification | Failure of, or inability to take part in or benefit from, bowel/bladder training; pharmacologic or surgical management failed or contraindicated |
| Renewal | A new prescription at least annually; a further signed order for added products or more units | Pull-on briefs: reassessment every six months |
Geisinger also states that its coding information does not constitute or imply coverage and that the benefit plan document governs.
Template gaps: quantity, usage and duration
A short template shows how much a minimal letter can leave out. The Children’s Mercy Kansas City template titled “Letter of Med Nec for diapers” has fields for date, patient, date of birth and diagnosis, plus a statement that the patient is non-verbal, non-ambulatory, dependent on caregivers and not capable of toilet training. It has no field for quantity, daily usage or duration. Set against the two policies above, those are exactly the items Geisinger lists for the prescription, and OHCA lists length of need, type of incontinence, height and weight. A template is a starting point for one clinic’s patients; the receiving payer’s list is the test.
Product type changes the documentation
Both payers treat product categories differently. OHCA defines diapers or briefs as items attached with tabs, pull-ons as slip-on items for an ambulatory member or one able to identify the need, and liners as worn inside a diaper or pull-on to increase absorbency. For pull-ons the member must be ambulatory or in toilet training, and a request is denied if the member is both non-ambulatory and unable to communicate needs. For diapers, pads or liners, documentation must support that the member is not amenable to a bowel/bladder training program or has failed one. OHCA lists T4521 to T4524 (with further codes) for disposable briefs and diapers, T4525 to T4528 for pull-ons, T4535 for liners and T4541 to T4542 for disposable underpads; the DME HCPCS codes guide explains how those code families are organised.
Geisinger covers pull-on briefs for six months when a condition causing incontinence is documented and the individual is actively taking part in a training program, with reassessment every six months. Generic disposable diapers and under pads fall under a different set of criteria, including an age of three years or older.
Where it matters for supply and procurement files
For staff who assemble supply orders, the practical use of the comparison is a pre-submission checklist built only from the items the two policies name. Confirm against the receiving payer’s own policy before relying on it.
- Signed, dated order naming the practitioner, the member and each item (code, narrative or brand).
- Diagnosis of the underlying condition, not only the symptom.
- Product category stated (brief, pull-on, liner, underpad), since the criteria differ.
- Units per day, anticipated duration and total quantity requested.
- Height, weight and type of incontinence where the payer uses them to support size and amount.
- Record of other treatments or training tried, where the payer asks for it.
- Renewal date: annual in the OHCA policy, six-monthly for pull-ons in the Geisinger policy.
Flexible-spending or health savings accounts use a different letter with a different purpose; see the letter of medical necessity for an HSA.
Common misunderstandings
“A signed letter guarantees approval.”
It does not. The payer applies its own criteria and, in OHCA’s words, makes the final determination.
“A diagnosis of incontinence is enough.”
Under the OHCA guideline it is not; the record must show an underlying condition involving loss of bladder or bowel control. Geisinger likewise asks for the condition causing the incontinence.
“One letter works for every payer and every product.”
The two policies differ on training requirements, pull-on rules, renewal intervals and quantity limits, so a letter written for one may be incomplete for another.
FAQ
Is a letter of medical necessity enough to get diapers covered?
No. OHCA states that a provider’s request does not in itself constitute medical necessity and that OHCA makes the final determination. Geisinger requires prior authorization by a plan medical director or designee.
What should a letter of medical necessity for diapers include?
It depends on the payer. Geisinger’s prescription must include the diagnosis of the condition causing the incontinence, the items, the number used per day, the anticipated duration of need and the quantity. OHCA also asks for height, weight, type of incontinence and expected length of need.
Is a diagnosis of incontinence alone sufficient?
Not under OHCA, which says a diagnosis of only urinary incontinence, fecal incontinence or enuresis is not sufficient; it asks for an underlying medical condition, injury or disability that involves loss of bladder or bowel control.
How often does the order need to be renewed?
OHCA requires a new prescription at least annually. Geisinger requires reassessment every six months for pull-on briefs. Federal Medicaid rules at 42 CFR 440.70 call for an annual physician review of the need for medical supplies.
Do these rules apply to Medicare or an HSA?
Not directly. See the guides on Medicare coverage of incontinence supplies and the letter of medical necessity for an HSA.
Sources
- Oklahoma Health Care Authority, Incontinence Supplies Guidelines, last review 10/1/2020, effective 10/14/2020: aem-prod.oklahoma.gov. Checked 2026-11-01.
- Geisinger Health Plan, Medical Benefit Policy MP274, Diapers and Incontinence Supplies (revised 8/24; latest review listed 8/26): geisinger.org. Checked 2026-11-01.
- 42 CFR 440.70, Home health services: Cornell LII. Checked 2026-11-01.
- Children’s Mercy Kansas City, Letter of Med Nec for diapers (template): childrensmercy.org. Checked 2026-11-01.
