If it's not a transmitter, then it's not certified (this has a meaning), you just need to have acceptable data on hand for your Supplier's Declaration of Conformity (SDoC). Then if you make any changes to your product after test, it is a judgement call whether you need to retest. Ultimately you are responsible for compliance, so this is not a free pass. In principle your computer or cell phone manufacturer could get fined if it is possible to operate their device with new user software in a way that emits RF above allowable levels.
If it is a transmitter and you-the-manufacturer make changes to software that operates the transmitter, the FCC has specific rules. Look at the KDBs for permissive changes and for Software Defined Radio Applications. Note that the FCC has a somewhat unique idea of what constitutes an SDR. Some software changes to radio firmware will require recertification but some just will require a permissive change. Some permissive changes are handled in a way similar to SDoCs, where you just get yourself a report with acceptable data, some require filing that data with the FCC.
If it's not a transmitter, then it's not certified (this has a meaning), you just need to have acceptable data on hand for your Supplier's Declaration of Conformity (SDoC). Then if you make any changes to your product after test, it is a judgement call whether you need to retest. Ultimately you are responsible for compliance, so this is not a free pass. In principle your computer or cell phone manufacturer could get fined if it is possible to operate their device with new user software in a way that emits RF above allowable levels.
If it is a transmitter and you-the-manufacturer make changes to software that operates the transmitter, the FCC has specific rules. Look at the KDBs for permissive changes and for Software Defined Radio Applications. Note that the FCC has a somewhat unique idea of what constitutes an SDR. Some software changes to radio firmware will require recertification but some just will require a permissive change. Some permissive changes are handled in a way similar to SDoCs, where you just get yourself a report with acceptable data, some require filing that data with the FCC.