Key points
- The FDA's Orange Book codes therapeutically equivalent products "A" (usually "AB" when bioequivalence data were submitted) and products it does not consider equivalent "B", with "BX" meaning the data are insufficient.
- In November 2014 the FDA changed two generic Concerta products from AB to BX because they might release drug more slowly in the 7 to 12 hour range.
- In the Orange Book data dated October 9, 2026, seven other manufacturers' generic methylphenidate extended-release tablets were rated AB to Concerta and one remained BX.
- An authorized generic is marketed under the brand's own application, may differ only in color or marking, and is not listed separately in the Orange Book.
- New York law requires a pharmacist to substitute a less expensive equivalent drug product unless substitution is prohibited, and New Jersey lets the prescriber indicate no substitution.
Most adults on ADHD medication take a generic at some point, sometimes without asking for it. Generics usually cost less, but people sometimes report that a new bottle seems to work differently, and the history of generic Concerta shows the question is not always imaginary. This article explains how the FDA decides that a generic is equivalent, what happened with methylphenidate extended-release tablets, what an authorized generic is, and how substitution works at pharmacies in New York and New Jersey. It does not recommend brand over generic or the reverse.
What the FDA requires of a generic
According to the FDA, a generic drug must be the same as the brand-name drug in active ingredient, conditions of use, dosage form, strength, route of administration and (with certain permitted differences) labeling. The company must show it is bioequivalent, meaning it "gets to the part of the body where the drug works at the same time and in the same amount." Inactive ingredients can differ, so the color, shape and filler of a generic often do.
Reading the Orange Book codes
The FDA's Approved Drug Products with Therapeutic Equivalence Evaluations, known as the Orange Book, gives each approved product a therapeutic equivalence code. The preface explains them:
| Code | What it means |
|---|---|
| A codes | No known or suspected bioequivalence problems, or problems that have been resolved. Considered therapeutically equivalent. |
| AB | The usual A code when data showing bioequivalence were submitted. |
| AB1, AB2 and so on | Used when more than one reference product of the same strength exists. A generic is equivalent to the reference product with the same three-character code. |
| B codes | Products the FDA does not at this time consider therapeutically equivalent. |
| BX | The data reviewed are insufficient to determine therapeutic equivalence. Presumed not equivalent until shown otherwise. |
The numbered codes matter for one ADHD product family. In the October 2026 data, generic mixed amphetamine salts extended-release capsules rated AB1 are equivalent to Adderall XR, while those rated AB2 are equivalent to Mydayis. They contain the same four salts but are not interchangeable with each other. The Orange Book preface also says it does not mandate which products are purchased, prescribed, dispensed or substituted, and that substitution is a matter of state law.
The generic Concerta story
Concerta is an extended-release methylphenidate tablet that its 2023 label described as an osmotic delivery system, releasing drug over many hours. The FDA's public record shows what happened with its first generics:
- November 13, 2014: the FDA announced concerns that two generic versions, made by Mallinckrodt and Kudco, might not be therapeutically equivalent. Its analysis found they "may deliver drug in the body at a slower rate during the 7- to 12-hour range," which could mean patients do not get the desired effect. It changed their rating from AB to BX. The products stayed approved and could still be prescribed, but were no longer recommended for automatic substitution. The FDA asked the companies to confirm bioequivalence within six months or withdraw the products.
- Same notice: the authorized generic, marketed by Actavis under a licensing agreement with the brand company, was found bioequivalent and substitutable.
- October and November 2016: the FDA proposed withdrawing approval of both products, saying the companies had failed to show their products provide the same therapeutic effect. On October 21, 2016 it approved another generic, marketed by Mylan.
The current picture comes from the Orange Book data files dated October 9, 2026. Generic methylphenidate extended-release tablets in Concerta's strengths from seven manufacturers were rated AB, and one product, held by Lannett, remained rated BX. This guide did not confirm whether the 2016 withdrawal proposals were completed or how the BX product relates to the 2014 products. If you want to know the rating of the exact product you received, ask the pharmacist for the manufacturer and check it in the Orange Book.
Product detail is in Concerta for adults and brand vs generic Concerta.
Authorized generics
The FDA describes an authorized generic as an approved brand-name drug marketed without the brand name on its label. It is the exact same drug product, though a tablet or capsule may have a different color or marking. It may be sold by the brand company or by another company with permission. Because it is marketed under the brand's own application, it is not listed separately in the Orange Book, and the FDA considers it therapeutically equivalent to the brand.
The FDA's listing of authorized generics, updated October 5, 2026, includes entries for several ADHD stimulants: Adderall XR, Focalin XR, Ritalin, Ritalin LA, Relexxii, Dexedrine Spansule and Methylin oral solution. Concerta does not appear on the listing, even though the FDA's 2014 notice described the Actavis product as an authorized generic identical to Concerta. The FDA cautions that the listing may be incomplete and does not say whether each product is still marketed.
Which ADHD medications have generics (October 2026)
| Medication | Generic in the Orange Book? | Note |
|---|---|---|
| Mixed amphetamine salts, immediate-release and extended-release | Yes | Extended-release generics are coded to either Adderall XR (AB1) or Mydayis (AB2); brand Adderall immediate-release tablets are listed as discontinued |
| Lisdexamfetamine capsules and chewables | Yes | First generic approvals listed August 25, 2023 |
| Methylphenidate extended-release tablets | Yes | Mostly AB; one product BX |
| Dexmethylphenidate immediate-release and extended-release | Yes | |
| Atomoxetine capsules | Yes | First generic approval listed September 16, 2010; brand Strattera is listed as discontinued |
| Viloxazine (Qelbree) | No | Brand only |
| Serdexmethylphenidate with dexmethylphenidate (Azstarys) | No | Brand only |
Having many generic makers does not guarantee supply. As of October 2026 the FDA drug shortage database still listed lisdexamfetamine and methylphenidate extended-release tablets as current shortages. See ADHD medication shortages in New York and in New Jersey.
Substitution at the pharmacy in New York and New Jersey
- New York: Education Law section 6816-a says a pharmacist "shall substitute a less expensive drug product" with the same active ingredients, dosage form and strength when the prescription does not prohibit substitution and the product is on the state's list. The label must show the name, strength and manufacturer of the drug dispensed, unless the prescriber specifies otherwise.
- New Jersey: under the state's generic substitution law (N.J.S.A. 24:6E), the prescriber can indicate that there shall be no substitution, interchangeable products are those the Department of Health has determined to be therapeutic equivalents, and pharmacies must post signs saying whether a drug may be substituted from the state's list of interchangeable products.
In practice, if you or your prescriber want a specific product, the prescription has to say so, and your insurance plan may charge more for the brand. Cost details are in ADHD medication cost in New York and in New Jersey.
If a new generic seems to work differently
- Check the label for the manufacturer and compare it with your last fill.
- Write down what changed and when, such as earlier wearing off, more side effects or less effect.
- Tell your prescriber. Do not change how you take the medication on your own.
- You or your clinician can report a suspected problem to the FDA through MedWatch.
Dr. Shershow, a psychiatrist licensed in New York and New Jersey, provides ongoing follow-up for adults on ADHD medication, which is the place to raise a change like this. See adult ADHD treatment.
Questions
Is a generic ADHD medication as good as the brand?
A generic rated AB in the FDA's Orange Book has been shown bioequivalent and is considered therapeutically equivalent to its reference brand. The 2014 generic Concerta downgrade shows that the FDA can change a rating when evidence raises doubt. If you notice a difference after a switch, tell your prescriber.
What is the difference between a generic and an authorized generic?
A generic is a copy made by another company and approved through its own application after showing bioequivalence. An authorized generic is the brand product itself sold without the brand name, possibly with a different color or marking.
Can my pharmacist switch my brand ADHD medication to a generic?
In New York, a pharmacist must substitute a less expensive equivalent product unless the prescription prohibits substitution. In New Jersey the prescriber can indicate no substitution. Ask your prescriber to note it if a specific product is clinically needed.
Are generic Adderall XR and generic Mydayis the same?
No. Both contain mixed amphetamine salts, but the Orange Book codes Adderall XR generics AB1 and Mydayis generics AB2, meaning each is equivalent only to its own reference product.
Is there a generic Vyvanse?
Yes. The Orange Book lists generic lisdexamfetamine capsules and chewable tablets, with first approvals dated August 25, 2023. Shortages of lisdexamfetamine were still listed by the FDA in October 2026.
Sources
- US Food and Drug Administration: Orange Book preface (therapeutic equivalence codes)
- US Food and Drug Administration: Orange Book data files (data dated October 9, 2026)
- US Food and Drug Administration: Orange Book search
- US Food and Drug Administration: Methylphenidate hydrochloride extended release tablets (generic Concerta) made by Mallinckrodt and Kudco
- US Food and Drug Administration: FDA list of authorized generic drugs (updated October 5, 2026)
- US Food and Drug Administration: FDA listing of authorized generics (content current as of October 5, 2026)
- US Food and Drug Administration (Drugs@FDA): Concerta prescribing information, October 2023 revision
- New York State Senate: Education Law section 6816-a, Substitution by pharmacists
- New Jersey Legislature: P.L.2015, c.130 (amending the generic substitution law, N.J.S.A. 24:6E)
- US Food and Drug Administration: Drug Shortages database (checked October 2026)
- US Food and Drug Administration: MedWatch safety information and adverse event reporting program
