This information is from our Gearwiki. Please contribute your own knowledge.

As part of our goal to provide information for personal loss prevention, we are developing a reference library of serial number information. Using this information, you can more accurately date an instrument, determine how genuine it is, and make the right buying or selling decisions. Currently, Martin serial numbers are found inside the guitar on the heel, printed directly on the wood. Any deviation from these numbers or this design could indicate a counterfeit instrument.

Here is a list of Martin Guitars Serial Numbers. Martin is very good for determining a year from this number, as their numbering system has been consistent from the point they began serializing their instruments. The serial numbers you see below are the LAST serial numbers produced during that year. The Backpacker guitars are numbered on a separate system, and aren’t accounted for in this dating material.

* Serial numbers 900,001 to 902,908 were used on Sigma-Martins in 1981 and 1982.

We’ll post Mandolin information on a separate page.

All information is quoted from Martin’s site.