I have a termal illnes can I file for SSDI

Yes, you can file for SSDI (Social Security Disability Insurance) and if you have a terminal illness you should do so immediately.  You can apply (1) online, (2) in person or by (3) telephone in the comfort of your own home.  Based on your description, by telephone sounds the most comfortable for you.   Regardless of the method you choose to apply, be sure to review the SSA's Disability Planner that provides contact information for the three methods to apply described above and important information you will need. I am uncertain if your case is a "compassionate allowance."  Click here for the list of diagnoses for your doctor to review that are compassionate allowances. Your question regarding the 401(k) is beyond my area of expertise. For SSI (Supplemental Security Income) cases payments can be made more quickly than usual if "a physician confirms by telephone or in a signed statement that an individual has a terminal illness with a life expectancy of six months or less; or a physician or knowledgeable hospice official (for example, hospice coordinator, staff nurse, social worker or medical records custodian) confirms that an individual is receiving hospice services because of a terminal illness;a physician confirms by telephone or in a signed statement that an individual has a terminal illness with a life expectancy of six months or less; or a physician or knowledgeable hospice official (for example, hospice coordinator, staff nurse, social worker or medical records custodian) confirms that an individual is receiving hospice services because of a terminal illness"