Trail Making Test Part A 

Trail Making Test Part A (TMT-A) is a timed paper-and-pencil or digital task that measures visual scanning and processing speed by having a patient connect numbered circles (1-2-3...) in sequence as quickly as possible. Completion takes roughly 1-3 minutes and is scored by total time in seconds, interpreted against age-normed reference data rather than a fixed pass/fail cutoff.

What TMT-A Measures

TMT-A is primarily a measure of processing speed and visual scanning, with secondary demands on sustained attention, visuomotor coordination, and basic sequencing ability. The patient is presented with a page (or screen) of numbered circles scattered in no particular spatial order and is instructed to draw a line connecting them in ascending sequence — 1 to 2 to 3, and so on — as fast as possible without lifting the pen or making errors.

Because Part A has no set-shifting requirement (unlike Trail Making Test Part B, which alternates numbers and letters), it functions as a relatively "pure" measure of scanning speed and motor tracking. This makes the A-B pairing clinically useful: subtracting or ratioing Part A from Part B helps isolate the executive/set-shifting component of Part B from baseline processing-speed and motor demands common to both trials.

Administration Time

Administration typically takes 1 to 3 minutes per trial. Many standardized protocols apply a discontinuation ceiling (commonly around 150 seconds) if a patient has not completed the trail, to limit frustration and testing burden. Total encounter time including instructions, a brief practice trial, and transition to Part B is usually well under 10 minutes when given as part of a battery.

Scoring and Interpretation

TMT-A is scored as the raw completion time in seconds, with errors (connecting circles out of sequence) typically noted separately and factored into examiner interpretation. Raw time is then converted to age-normed T-scores or percentiles using published normative datasets — commonly cited sources include Heaton and colleagues' demographically corrected norms, among other normative reference sets used across neuropsychology practices.

There is no single universal cutoff score that defines "normal" versus "impaired" performance on TMT-A. Normative comparisons vary by the dataset used, and interpretation should always account for age, education, and — where available — a same-patient baseline (e.g., a preseason baseline in sports medicine settings). In general, markedly prolonged completion times relative to age-matched peers, or an unusually high error count, suggest reduced processing speed and warrant clinical correlation rather than a standalone diagnostic conclusion. Clinicians should treat any single TMT-A score as one data point within a broader clinical picture, not an isolated diagnostic threshold.

Clinical Use Case

TMT-A is one of the most frequently administered instruments in neuropsychological practice because it is brief, has good normative support, and is sensitive to diffuse effects on processing speed — a common finding after mild traumatic brain injury and concussion. It is typically administered as part of a broader battery rather than in isolation, often alongside Trail Making Test Part B, Digit Span, the Stroop Color and Word Test, or SDMT, when a clinician wants a fuller picture of attention, working memory, and executive function alongside raw processing speed.

In concussion care specifically, TMT-A serves as a sensitive marker within the processing speed domain, useful for tracking recovery trajectory over serial administrations — particularly when paired with an individual patient baseline collected before or shortly after injury.

CPT Code: How TMT-A Is Billed

TMT-A is not billed as a standalone code. As part of a formal neuropsychological or psychological test battery, its administration and scoring is captured under:

• 96136 — test administration and scoring by a physician or other qualified health care professional (QHP), first 30 minutes, two or more tests, any method — with 96137 as the add-on for each additional 30 minutes.
• 96138 — the equivalent administration/scoring code when a trained technician administers the test, with 96139 as the additional-increment add-on.
• Interpretation, integration of results across the battery, and the written report fall under 96132/96133 (neuropsychological testing evaluation services).

In some legacy billing contexts, brief standalone cognitive screens were reported under CPT 96125, but that code was largely narrowed or replaced by the 2019 code family revisions — current guidance should be verified against CMS and payer-specific policy before use. Who administers the test (physician/QHP vs. technician), how much time is spent, and the payer's local coverage policy all affect which code family applies.

This page provides general educational information about CPT and RTM billing codes. It is not coding advice, a guarantee of reimbursement, or a substitute for your own compliance review. Payer coverage and documentation requirements vary by plan and can change — verify current requirements with CMS, your Medicare Administrative Contractor, and each payer before billing.

Where TMT-A Sits in the Kavera Protocol

Within Kavera's Cognitive Health module, TMT-A is included as one component of the broader cognitive-domain testing that runs alongside symptom, mood, and sleep instruments in the platform's assessment battery. It is also relevant to the Concussion module, where serial processing-speed tracking supports return-to-play and return-to-learn decisions over the course of recovery.

How Kavera Handles This

Trail Making A runs between visits in the Concussion and Cognitive Health modules, timed and scored on completion. Kavera plots it against baseline and beside Part B so processing speed and set-shifting are read together. The record supports 96136–96139 and RTM documentation. Self-Serve practices run this with their own staff. On Managed, Juliet Mott's team runs it and bills it under your credentials.

FAQ

How long does Trail Making Test Part A take to administer?

Most patients complete TMT-A in 1 to 3 minutes. Many protocols cap the trial at around 150 seconds if the patient has not finished, to keep testing burden low.

What is a "normal" score on TMT-A?

There is no single universal normal score. Raw completion time is converted to an age-normed percentile or T-score using a published normative dataset, and results are best interpreted relative to age, education, and — where available — the patient's own baseline rather than a fixed cutoff.

Is Trail Making Test Part A the same as Part B?

No. Part A requires only number sequencing and primarily measures processing speed and visual scanning. Part B alternates between numbers and letters, adding a set-shifting demand that measures executive function. Comparing A and B performance helps isolate the executive component from basic processing speed.

What CPT code covers Trail Making Test Part A?

TMT-A administration and scoring is typically billed under 96136/96137 (physician/QHP) or 96138/96139 (technician-administered), with interpretation and report captured under 96132/96133 when part of a full battery. Exact billing depends on who administers the test and payer policy.

When is TMT-A used in concussion care?

TMT-A is commonly included in post-concussion neuropsychological batteries to track processing-speed recovery over time, often administered serially and compared against a preseason or early post-injury baseline as part of a broader return-to-play or return-to-learn evaluation.