What the mandated service has to catch is specified, and the specificity is the useful part. 16 CFR 609.2(l) defines "material additions or modifications" as significant changes to a consumer's file, including new accounts opened in the consumer's name and new collection accounts; inquiries or requests for a consumer report; material changes to a consumer's address; changes to credit account limits of $100 or greater; and negative information. Section 609.2(n) then defines negative information as accounts furnished as more than 30 days delinquent, accounts furnished as being included in bankruptcy petition filings, and new public records, "including, but not limited to, bankruptcy filings, civil court judgments, foreclosures, liens, and convictions".
The inquiry limb has an exclusion that changes what silence means. Under 609.2(l)(2)(i), an inquiry made for a prescreened list obtained in order to make a firm offer of credit or insurance, or made for the purpose of reviewing or collecting an account of the consumer, "shall not be considered a material addition or modification". So the two commonest categories of pull on a settled file, the marketing prescreen and the existing creditor's periodic review, are deliberately not reported. A quiet month is not evidence that nobody looked.
There is a deadline, and it is short. 16 CFR 609.4 requires the notice to be provided "within 48 hours of any material additions or modifications to a consumer's file". Section 609.2(h) defines electronic notification as a notice by mobile application, email or text message, and adds that where the notice itself does not tell you which specific change was made, it must link to a page that does. Section 609.2(g) requires the service to give access, following a notification, to all the information in the file at the time of the notification, which is what makes the alert actionable rather than merely alarming.
The rule anticipates being used as a sales channel and forbids it. 16 CFR 609.3(e)(1) requires that once a consumer is in the process of enrolling, any advertising or marketing of other products be delayed until after enrollment is complete, and (e)(2) prohibits communications that "interfere with, detract from, contradict, or otherwise undermine" the purpose of providing the free service. The examples given in (e)(3) are instructive about what the Commission expected: material implying that a paid product must be bought in order to get the free service, and material falsely representing an ancillary product such as identity theft insurance as free, or failing to disclose prominently that a service advertised as free for an initial period must be cancelled to avoid charges. Section 609.3(f) adds that the agency may not require the consumer to agree to any terms or conditions beyond those needed to comply with law.
Eligibility is broader than "deployed", and it lasts two years at a time. 15 USC 1681c-1(k)(1) expressly includes a member of the National Guard, and 16 CFR 609.3(c)(2) deems an agency compliant if it serves consumers who self-certify active duty status, reservists called to active duty, or National Guard membership. Under 609.3(c)(3) a verification is valid for two years, after which the agency may ask for proof again.
One limitation on this particular right is unusual and worth knowing. Under 15 USC 1681c-1(k)(4), the Fair Credit Reporting Act's civil liability provisions at 1681n and 1681o "shall not apply to any violation of this subsection", which is enforced instead "exclusively" by the federal agencies and federal and state officials identified in 1681s. So a service member who is denied the free monitoring has an enforcement route through regulators rather than a private damages claim under those sections.
For a commercial product, the contract is the specification. Everything above describes the mandated service. A paid subscription is governed by its own terms, and the questions that decide what it is worth are which of the three bureaus it watches, since a file at an unwatched bureau can change without a notification, what it counts as an event, how fast it notifies, and which score it shows. On that last point the published material on credit scores, FICO Scores and VantageScore explains why the number in a monitoring app is often not the number a lender will use. Note also that monitoring keeps working through a freeze: a file monitoring service you subscribed to is one of the statutory exceptions in 15 USC 1681c-1(i)(4), set out in the published material on credit freezes.