Inclusion Criteria:  Veterans receiving services through the MVAHCS  History of mild TBI according to VA/DoD Clinical Practice Guidelines (2009) with one or more of the following criteria present after head injury:  Loss of consciousness between 0-30 minutes Post-traumatic amnesia between 0-24 hours Alteration of consciousness/mental state up to 24 hours Glasgow Coma Score between 13-15 (best available score within first 24 hours)  Post-traumatic headaches defined by International Classification for Headache Diagnosis 3rd Edition (ICHD-3) guidelines with the following criteria present:  Headaches developing within seven days following trauma or injury to the head and/or neck Headaches persisting beyond three months  Chronic daily headaches defined by clinical standards with the following criterion present:  o 15 or more headache days per month  Men and women 18-75 years of age Possess a smartphone and agree to download and use the EMA application on their personal device Capable and willing to provide voluntary informed consent  Exclusion Criteria:  History of moderate or severe TBI according to VA/DoD Clinical Practice Guidelines (2009) with one or more of the following criteria present after head injury:  Loss of consciousness greater than 30 minutes Post-traumatic amnesia greater than 24 hours Worst Glasgow Coma Scale less than 13 within the first 24 hours unless invalidated upon review (e.g., attributable to intoxication, sedation, systemic shock) Abnormal structural imaging Current (within six months of enrollment) psychosis and mania Current (within one month of enrollment) substance dependence with the exclusion of opioids  Personal history of epilepsy or seizure disorder  o Does not include seizures therapeutically-induced by ECT or identified as a single seizure event (based on the principal investigator's judgement)  Metal particles in the eye or head (exclusive of the mouth) (e.g., shrapnel, fragments from welding or metalwork, etc.) Implanted medical device above the clavicle (e.g., aneurysm clips, shunts, stimulators, cochlear implants, electrodes, etc.) Significant neurological disorder or insult that would impact risk (based on the principal investigator's judgement and research literature) Current use of medications with significant potential for lowering seizure threshold Current benzodiazepine usage at a dose higher than 3mg of lorazepam or equivalent Electroconvulsive therapy (ECT) or cortical energy exposure within one month of enrollment (including participation in any other neuromodulation treatments or studies) Current (within one month of enrollment) participation in another interventional study that would impact the results of this research Inadequate communication (e.g., language barrier) Women who are pregnant, trying to become pregnant, or breastfeeding Women of childbearing age/potential who are not using a medically-accepted form of contraception when sexually active