How do you know when to apply for TDIU?

You should apply for TDIU when your service-connected disabilities prevent you from securing or following substantially gainful employment, even if your combined scheduler rating is less than 100%. Based on your 90% rating and worsening pain post-surgery, you likely meet the basic eligibility criteria of having one disability rated at least 60% or multiple with a combined 70% rating (one at 40% or higher) as outlined in **38 CFR 4.16(a)**. The key is demonstrating unemployability, not just pain; you must show your conditions, particularly those addressed in your pain management, cause functional impairment in a work environment, such as marked interference in work relationships, reliability, or productivity, per the criteria in **38 CFR 4.130** for mental disorders or analogous standards for physical conditions. Case law like *DeLuca v. Brown* supports considering the combined impact of all disabilities and their worsening over time, while *Buchanan v. Nicholson* emphasizes that marginal employment (e.g., odd jobs, protected work) does not preclude TDIU. Your actionable next steps are: 1) Gather supporting evidence, including statements from your pain management doctors detailing your work limitations, 2) Obtain employment history statements from former employers or coworkers, 3) Complete **VA Form 21-8940** (Veteran’s Application for Increased Compensation Based on Unemployability) and **VA Form 21-4192** (Request for Employment Information) for your past employers, and 4) File a fully developed claim with this evidence, explicitly requesting TDIU, as it is not automatically considered. *Disclaimer: This information is for educational purposes regarding VA claims processes and is not intended as legal or medical advice; for personal guidance, consult an accredited VA attorney or claims agent.*