I’m an AF guy but the Army Summary does a pretty decent job covering what duty counts toward the 20 years of service requirement (7200 points).
DoD Disability Retired Pay
Summary
The Department of Defense (DoD) compensates Soldiers who are retired for physical disability (Title 10 USC Ch. 61). The Secretary of the Army (SA) may retire a regular component Soldier who is deemed physically unfit to perform their duties as the result of an injury incurred in the line of duty. To qualify for disability retirement, the Soldier must have completed at least 20 years of creditable service , in accordance with
10 USC 1208, or have service-connected disabilities that caused the Soldier to be unfit for duty and amount to a combined disability rating of 30 percent or more. The 20-year threshold established by
10 USC 1208 includes Reserve "equivalent duty service" (the product of the Soldier's membership and Inactive Duty Training (IDT) points divided by 360). This service is applicable to Regular Soldiers with former Reserve Service.
The AF says he same thing:
AFI36-3212
3.17.2. Permanent Disability Retirement. Applies to service members who have been found unfit, the condition is stable and permanent, and the total disability rating is 30 percent or greater or the service member has 20 years or more service computed under 10 U.S.C. § 1208 regardless of the combined compensable disability rating.
Title 10 U.S.C. § 1208
(a)For the purposes of this chapter, a member of a regular component shall be credited with the service described in paragraph (1) or that described in paragraph (2), whichever is greater:
(1)The service that he is considered to have for the purpose of separation, discharge, or retirement for length of service.
(2) The sum of—
(A) his active service as a member of the armed forces, a nurse, a reserve nurse, a contract surgeon, a contract dental surgeon, or an acting dental surgeon;
(B) his active service as a member of the National Oceanic and Atmospheric Administration or the Public Health Service; and
(C) his service while participating in exercises or performing duties under sections 502, 503, 504, and 505 of title 32.
Title 32
32 U.S. Code § 502 - Required drills and field exercises
32 U.S. Code § 503 - Participation in field exercises
32 U.S. Code § 504 - National Guard schools and small arms competitions
32 U.S. Code § 505 - Army and Air Force schools and field exercises
ANGI36-2001
3.2. Inactive Duty Training (IDT). IDT consists of attendance at regularly scheduled drills, additional IDT periods, and voluntary IDT. IDT provides individual or unit readiness training to ANG members. 32 U.S. Code § 502, 37 U.S. Code § 206(e), DoDI 1215.06 and DoDI 1215.13 establish basic policies and governing authority for conducting IDT. IAW 37 USC Section 206 (d) (1-2) IDT may not be used for correspondence courses, to include electronic-based distributed learning.
DODI 1215.06
a. IDT. IDT consists of attendance at regularly scheduled unit training periods (regularly scheduled drills), additional IDT periods, and voluntary IDT.
From the 15 year Pre-retirement Brief (Ohio)
1405 Time – IDT points earned while a member of the Reserve Component used to increase the percentage of base pay multiplier of a Regular retirement.
• Used to determine Non-regular retirement eligibility
• For regular retirement the points count AFTER acquiring 20 years of active service
• May be used to reach 20 years of active service for disability retirements.
• Points cannot exceed 365/366 points total per retirement year