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General product information only, not medical advice. For fitting or any clinical question, speak with a qualified clinician.
The original ASO ankle stabilizer, made by Medical Specialties, Inc., is sold in eight sizes keyed to ankle circumference in inches, from 9 in (XX-Small) up to 16 in and over (3X-Large). The chart below reproduces the manufacturer’s own size table, with the black and white part number for each size, so you can match a size to an order or a label.
ASO ankle brace sizing chart (original ASO Ankle Stabilizer)
Source: the manufacturer’s ASO Ankle Stabilizer product page (Medical Specialties, Inc.), checked 2026-11-01. Ankle circumference is in inches.
| Size | Ankle circumference | Black part no. | White part no. |
|---|---|---|---|
| XX-Small | 9–10 in | 264019 | 264009 |
| X-Small | 10–11 in | 264011 | 264001 |
| Small | 11–12 in | 264012 | 264002 |
| Medium | 12–13 in | 264014 | 264004 |
| Large | 13–14 in | 264015 | 264005 |
| X-Large | 14–15 in | 264016 | 264006 |
| XX-Large | 15–16 in | 264017 | 264007 |
| 3X-Large | 16 in and over | 264018 | 264008 |
Check your product’s labelling. Part numbers, sizes and ranges can change between product versions, so confirm against the label and the instructions for use that come with the product you actually hold.
How to read the chart
Find the row whose ankle circumference range contains the measured value. The size name (XX-Small to 3X-Large) is what appears in the product name; the part number identifies one size in one colour. Black and white versions share the same circumference ranges, and only the last digits of the part number differ between colours.
The ranges are written as 9–10, 10–11, 11–12 and so on, so a value on a boundary, such as exactly 11 in, appears in two adjacent rows. The chart itself does not say which row applies, so do not assume. Check the manufacturer’s current chart and instructions for use, or ask the supplier.
How to measure or choose
The manufacturer’s product page gives the size as an ankle circumference but its text does not state where on the ankle to measure, so this guide does not specify a measuring location. Use the instructions that come with the product, the manufacturer’s own sizing material, or the guidance of the clinician who is fitting the brace.
For how other makers define their sizing basis, see the lace-up ankle brace guide, and for general wearing guidance see how to wear an ankle brace. Other ankle support types are covered in ankle brace types, and a sibling lookup page is the knee brace sizing chart.
Equivalence notes: ASO ankle stabilizer sizing across models
ASO Speed Lacer
The ASO Speed Lacer Ankle Stabilizer uses the same circumference bands for X-Small (10–11 in) through XX-Large (15–16 in), with its own part numbers (black 223611, 223612, 223614, 223615, 223616, 223617). Two differences from the original appear on its manufacturer page: XX-Small (9–10 in) is listed in black only (223619), and no 3X-Large is listed. White Speed Lacer numbers are 223601, 223602, 223604, 223605, 223606 and 223607. Source: Medical Specialties, Inc. product page, checked 2026-11-01.
Left and right
Both manufacturer pages describe the brace as bilateral, fitting either the left or right foot, so there is no left or right size to order.
Shoe size
This guide gives no shoe-size equivalents because the manufacturer’s table above is by ankle circumference. If a shoe-size or S/M/L conversion is needed, use the manufacturer’s current published chart.
Common mix-ups
- Original versus Speed Lacer. Their part numbers differ (264xxx versus 223xxx) even where the circumference bands match. A Speed Lacer number will not appear on the original’s chart.
- Size name versus colour. Each part number covers one size in one colour. Check both on the box.
- Boundary values. Adjacent bands share an end value (see above).
- Assuming a left and right pair. The brace is bilateral, so a single unit fits either side.
Receiving check
When a delivery arrives, compare the size, colour and part number on the packaging with the order, and confirm the instructions for use are in the box. The Speed Lacer instructions state that the product is for single patient use only and that there is no guarantee it will prevent injury; it is warranted against defects in materials and workmanship for six months from shipment. The instructions for use of the model you receive cover care and washing.
FAQ
How is the ASO ankle brace sized?
The manufacturer sizes the original ASO Ankle Stabilizer by ankle circumference: for example Small is 11–12 in and Medium is 12–13 in. The chart above lists each size and part number; confirm against the product labelling.
How is ASO ankle stabilizer sizing different from shoe size?
The manufacturer’s table on its product page is by ankle circumference, not shoe size. No shoe-size conversion is given here.
Is there a left and right ASO ankle brace?
No. The manufacturer describes it as bilateral, fitting either the left or right foot.
Does the ASO ankle brace have a HCPCS code?
The manufacturer’s page lists “PDAC Verified HCPCS: L1902” for the original ASO Ankle Stabilizer. Coverage and billing depend on the payer.
Sources
- Medical Specialties, Inc., “ASO Ankle Stabilizer” product page: https://medspec.com/product/aso-ankle-stabilizer/ (checked 2026-11-01).
- Medical Specialties, Inc., “ASO Speed Lacer Ankle Stabilizer” product page: https://medspec.com/product/aso-speed-lacer-ankle-stabilizer/ (checked 2026-11-01).
- Medical Specialties, Inc., ASO Speed Lacer Instructions for Use (PDF): https://medspec.com/wp-content/uploads/2023/03/2-Instructions-for-Use.pdf (checked 2026-11-01). ASO is a registered trademark of Medical Specialties, Inc.
