Part 135 medical certificate requirements: class, currency, and what the dispatch gate checks

Medical currency is one of the most commonly misread items in a pre-dispatch crew check. The rules are not complicated, but they are easy to misapply — especially when age transitions change the expiry window mid-year without anyone updating the crew record.

What class is required for Part 135

Under 14 CFR 135.243, a pilot acting as PIC of a Part 135 operation must hold at least a second-class medical certificate issued under 14 CFR Part 67. A third-class medical is not sufficient for PIC under Part 135.

A pilot acting as SIC (second in command) must hold at least a third-class medical under 135.245 — unless the operation requires an SIC by type (e.g., a multi-engine turbine requiring two pilots), in which case second-class is typically expected by practical convention even if the regulation allows third.

A first-class medical is not required for Part 135 PIC — unless the operator's OpSpecs specify otherwise or the pilot is also acting as an air carrier ATP (e.g., in a Part 121 cross-utilization scenario). For pure on-demand Part 135 PIC, second-class is the floor.

Expiry windows — the age break matters

The currency of a second-class medical depends on the holder's age at the time of the exam:

A second-class medical is valid for 12 calendar months regardless of age — but there is a critical nuance. When a second-class expires, it downgrades to third-class currency (24 or 60 months depending on age), which is not sufficient for Part 135 PIC. The moment the 12-month window closes, the pilot cannot act as PIC under 135, even if the physical certificate is still valid as third-class.

This is the most common medical currency error in dispatch: "their medical is still valid" is true for third-class privileges but not for second-class privileges. The dispatch gate must check the exam date against the 12-month window, not the certificate expiry date printed on the physical document.

The age-40 transition trap

A pilot who turns 40 during the validity period of a medical issued before age 40 does not get a shorter validity period — the 12-month window for second-class runs from the exam date regardless. But when they renew, they are now "age 40 or older" for the purposes of first-class validity. Second-class is unaffected.

The dispatch system needs to compute currency from the exam date, not from an age-based table lookup, to handle this correctly.

BasicMed — not valid for Part 135

BasicMed (14 CFR 61.113(i)) is not valid for Part 135 operations. It applies only to operations under 61.113 — private pilot operations, not commercial. A pilot holding only BasicMed cannot act as PIC for any Part 135 flight, regardless of aircraft weight or passenger count.

This comes up when a pilot's second-class has lapsed and they obtained BasicMed to maintain some flying privileges. BasicMed does not restore Part 135 PIC eligibility.

Sport pilot and recreational pilot medicals

Not applicable to Part 135. Any pilot acting as PIC under Part 135 must hold an FAA medical issued under Part 67, minimum second-class.

How the pre-dispatch gate checks medical currency

The gate computes the expiry date as (exam date + 12 calendar months) and compares it to the proposed flight date. If the medical expires before the flight, the gate returns UNABLE with citation 135.243 and the expiry date.

The 60-day buffer convention is worth understanding: some operators flag medical currency as a warning at 60 days out to give enough lead time to schedule a new AME appointment, even though the legal expiry is 12 months. This is a policy choice, not a regulatory requirement. The UNABLE is issued at the legal expiry, not at the 60-day flag.

Third-class or BasicMed in the crew record triggers an immediate UNABLE for PIC dispatch — not a warning. There is no window in which a third-class medical is sufficient for Part 135 PIC.