Not if you take 3 weeks off work under the FMLA (Family Medical Leave Act). You can actually take that 3 weeks off and have your employment there protected. It's a federal law compliance thing that your employer is required to follow. But you have to get the right paperwork, get your employer to sign-off on it, etc. I would talk to an FMLA and ADA representative about it. You are legally entitled to 12 weeks of paid leave from your employer, under the FMLA. I have included a few links for you and your wife to peruse. I would act quickly to get that 3 week program covered. If you have to, contact the program and ask them to help you get the correct FMLA forms for your employer to fill-out, so that your job is protected and you can complete that 3 week program without worrying about losing your job.

https://www.dol.gov/whd/regs/compliance/whdfs28f.pdf

Access Denied

What Medical Conditions Are Covered Under FMLA? - FMLA Assistance

Keys to FMLA, ADA Compliance for Mental Health Are Communication, Flexibility

Is Your Disability a Serious Health Condition Under the FMLA? | DisabilitySecrets

https://www.nolo.com/legal-encyclope...-the-fmla.html