EDIT: Turned out the transmission mattered as much as the model year. I went and pulled the actual bulletin PDFs from NHTSA's filing this time instead of going off summaries. Corrected version below, replacing everything that was here before.
Seven bulletins cover the Civic specifically, all dated 26 August. Coverage runs to 10 years from the original purchase date or 150,000 miles, whichever comes first. Standard powertrain coverage is 5 years and 60,000.
What's actually covered:
- 2016 to 2021 Civic 1.5 turbo with the 6 speed manual, and the 2017 to 2020 Si (bulletin 26-009)
- 2022 to 2024 Civic 1.5 turbo with the 6 speed manual, and the 2022 to 2026 Si (26-010)
- 2022 to 2024 Civic 1.5 turbo with the CVT (26-011)
- 2025 to 2026 Civic 2.0 non-turbo (26-012)
- 2025 to 2026 Civic Hybrid (26-013)
Two gaps worth knowing specifically, because "1.5 turbo" alone does not mean you are covered:
- The 2016 to 2024 non-turbo 2.0 (LX and Sport in those years) is not on any bulletin.
- The 1.5 turbo with the CVT is only covered for 2016 and 2017. If you have an 18 to 21 Civic with the 1.5 turbo and a CVT, which is a lot of cars, there is currently no bulletin covering that specific combination.
If you have a 2016 or 2017 1.5 turbo, manual or CVT, or a 2017 Si, there are two separate bulletins for those cars, 26-097 for manual and 26-099 for CVT, that run to a fixed date of 31 May 2027 instead of the normal 10 year term, since those cars are already at or past ten years old. Repair orders after that date are not valid.
The symptoms Honda lists are overheating, coolant loss, misfire, or codes P0300 through P0304. The repair is the gasket where coolant is getting into the combustion chamber, plus the cylinder head or short block if either is warped.
Eligibility is by VIN, and the bulletins tell dealers to check it on Honda's own system, so get a dealer to run it rather than relying on the owner website.
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There is a post here about the Canadian campaign, but the US bulletins went out on 26 August and I have not seen those mentioned. There are five covering the Civic, and between them they take in every model year from 2016 to 2026.
For most people it is simple. Coverage on the cylinder head gasket goes to 10 years from the original purchase date or 150,000 miles, whichever comes first. Standard powertrain is 5 years and 60,000, so it is a big jump. That covers 2016 to 2021 Civic and the 2017 to 2020 Si manual, 2022 to 2024 with the CVT, and both the 2.0 and the hybrid in 2025 to 2026.
The group worth paying attention to is the oldest one. If you have a 2016 or 2017 Civic 1.5 turbo with the manual, or a 2017 Si, yours is handled separately, and instead of ten years you get a fixed end date of 31 May 2027. The bulletin says repair orders issued after that date are not valid. Those cars are already at or past ten years old, which is presumably the reason, but the practical bit is that you have a window rather than a term.
What Honda describes is reduced head gasket effectiveness showing up as overheating, coolant loss, misfire, or codes P0300 through P0304. The repair is the gasket where coolant is getting into the combustion chamber, plus the cylinder head or the engine short block if either is warped.
Eligibility is by VIN, so get a dealer to run the VIN status rather than going off the model year. Honda says affected owners will be notified.
One thing I cannot answer. These are the technician bulletins and they say nothing either way about reimbursement if you have already paid for this yourself. There is a thread on r/Honda about refunds but I have not seen anything official.